subject: Interacting With Machines Using The Touch Screen Display And Silicone Keypads [print this page] Designers are constantly trying to make the interface between man and machine more user friendly and interactive. Starting with the clanking keys of a typewriter, the technology progressed to the common computer keyboard which made typing easier and simpler. However, these keypads were not without problems. The plastic keypads present a hard surface for the fingers to touch. These keypads are easy targets for failure, breakage, and are permeable to moisture and water. This limits the scope of usage to computers and indoor applications. A more versatile solution for some applications is the Silicone Keypad. Silicone (also called Rubber, Elastomer, or Elastomeric) Keypads have made themselves an indispensable part of the set-up in many commercial establishments, industrial facilities, public offices, outdoor applications and in homes.
Silicone Keypads are preferred for use in phones. The Silicone Keypads are easy to use and have a soft touch. If a hard feel is required, the plastic keycap is used over a silicone mat. The silicone keypads are made with a compression-molded silicone compound. These Silicone Keypads are long lasting. The applications of these Silicone Keypads are boundless. The conductive Silicone Keypads are integrated with flex boards, printed circuit boards and membrane switches. They can even be custom designed to be used as rubber switches. Silicone is available in solid colors or translucent colors making them a great option when backlighting is required. There are many companies around the world offering compression molded silicone. However, when comparing suppliers it is not only important to consider pricing, but also quality, length of time in business, and customer service.
Another milestone witnessed in the development of man machine interface is the Touchscreen Display. The Touchscreen Display is commonly available in three forms; infrared, capacitive and resistive. Resistive Touchscreen Displays are cheaper and are further classified as analog and digital displays.
The Analog Touchscreen Display is used in cases when the maximum resolution of the switches required exceeds the limit with digital screen. Each layer has an X or Y axis and when the layers are placed on top of one another, a switch is created. Thus a voltage drop is detected when the screen is touched which is interpreted as a location on the screen by the processor. Also called the X-Y matrix, the Digital Touchscreen Display is designed with a number of columns and rows by etching the screen with a coating of ITO. On assembly, a screen is formed with distinct switches. The resolution depends on the columns and rows.
An important advantage of the Touchscreen Display is their easy integration with membrane switches. Membrane switches offer discreet keys and can be used for simple or common key strokes (i.e; enter function). The advent of Touchscreen Displays and Silicone Keypads are one of the many improvements in technology driven by human need, that have reduced work stress and improved efficiency.
