Touchpad predecessors
Do you want to know what a touchpad is? This term appeared in 1988. Before that, there were devices called trackball and trackpoint. And before them, the cursor was controlled with the mouse.
The basis of the design of the trackball is a ball, the same as in a mechanical mouse. Old mechanical mice were moved on a special rug, the ball rolled inside and, touching the sensors, generated a signal that moved the cursor across the screen. But, after working with a mouse for several hours, you will understand that this is not the most convenient option. Therefore, the designers came up with the following device for controlling the cursor - the trackball (the mouse is vice versa). The trackball ball is mounted on top or on the side, there are two buttons next to it, as in a conventional mouse. The palm rests motionless on the table, and only the thumb moves, turning the trackball ball. The ball can be from 1 to 6 cm in diameter. There are trackball designs in which the ball is controlled by the index, middle, or ring fingers. On most models (except buttons and a ball), a wheel is installedscroll. The main advantage of the trackball is the immobility of the hand in the wrist.
Rotating the ball with your finger gives more accurate cursor positioning. But the trackball has a serious drawback - open at the top, it gets dirty very quickly. In addition, mechanics are mechanics, and mechanical devices are less reliable than electronic counterparts. After the trackball came the trackpoint. It consists of two resistive sensors that change their resistance under the action of a force applied to them (strain gauges). The cursor moves according to the applied force. The trackpoint has two buttons similar to mouse buttons. The disadvantages of this device are the drift of the cursor, as well as the need to press on the panel, which can lead to spasms of the muscles of the hand during prolonged use.
What is a touchpad?
The development of technical means of touch control has led to the fact that it became possible to create a new generation device for controlling the computer cursor. Thus the touchpad was born. Consider what a touchpad is (and how it works). The touchpad works like a conventional touch switch: the operator touches the sensitive (touch) pad with his finger, the electrical circuit is closed and the switch is activated. Later, it was not the electric circuit that began to close with the finger, but when it was introduced into the zone of the sensory area, the capacitance of the space changed (and the electronic switching circuit worked). So the touchpad became the basis of the touchpad. Apple has bought a license from the inventor of a touch pad that reacts not onlyon pressing, but also on the movement of the finger. After design and technological development (in 1994), the touchpad appeared in portable computers. True, it was called TrackPad (as Apple still calls it).
The touchpad has a number of advantages:
- placed in the design of the laptop, does not require additional space for itself;
- does not require a flat surface (like a mouse);
- the reliability of the electronic rather than mechanical device is higher;
- the ability to simulate pressing any mouse button;
- slight movement of the finger moves the cursor around the screen;
- has good protection against dust and moisture.
Disadvantages include:
- low resolution and (difficulties in working with graphic programs);
- does not work when using a pencil or pen;
- does not react with a small touch zone;
- once every few months requires cleaning the touch pad.
Touchpad in laptops
The touchpad in laptops is used very widely, because it was developed specifically for them. Touchpads in laptops of recent years provide not only single and double clicks of the mouse, but also vertical and horizontal scrolling. Some even recognize multi-finger touches, and even gestures: rotate a picture or scale an image (text) with two fingers. It is usually installed below the keyboard (in the middle) and has two physical mouse buttons. There are touchpads that are structurally independent of the laptop, connected like a mouse (wired through a connector or over the air).
Now you know what a touchpad is.
