Capacitive Touch Panels
These touch panels have multi-touch ability and are extremely durable in most environments including withstanding water contact, dust and grease. Capacitive touch panels will activate with either a bare finger or a capacitive stylus and have excellent dragging performance. Newhaven Display offers capacitive touch panels with mutual capacitive sensors on the 3.5", 4.3", 5.0" and 7.0" TFTs. These capacitive touch panels come with a built-in I2C interface controller. This allows for quick time to market while keeping development costs low.
Key Features and Advantages
Built-in controller with I2C interface (400KHz)
Multi-touch capability: touch, lift, directional & zoom gestures
Sizes designed to mate with 3.5", 4.3", 5.0" and 7.0" TFTs
6H hardness, >1 million touches
82% light transmittance
6mA at 3.3V power supply
0.03mA sleep mode
As capacitive screens don't need much contact at all, you can swipe across them very lightly and get just as good a response as you would with a slow, heavy drag. Capacitive Touch Panels are made of an insulator that is coated with a transparent conductor. Typically, Capacitive Touch Panels consist of glass as the insulator coated in indium tin oxide (ITO). The human body is also an electrical conductor, so when the human body comes into contact with the Capacitive Touch Panel, the touch panel's electrostatic field becomes distorted. It is this distortion that is then read by the touch panel controller and, depending on the program written, the display will respond accordingly.
Projected capacitance has an etching on the conductive layer which forms a grid pattern allowing it to be more accurate and have a more flexible operation. The grid pattern on the conductive layer is either created by etching on either a single layer of a conductive layer or by etching parallel lines on two separate perpendicular layers of conductive layers. Since this type of capacitance has a greater resolution, the touch panel can operate without direct contact allowing it to be operable under screen protectors or other protective insulating layers. In addition to the human body, projected capacitance can also interact with an active or passive stylus. There are two different sensor types for projected capacitive touch panels: Mutual Capacitive and Self Capacitive.
Resistive Touch Panels
These touch panels are designed to allow items other than your finger to activate the touch. Resistive touch panels don't rely on organic properties of your finger so you have more options to interact with them. Resistive technology senses pressure which is why a gloved hand will work, but it requires harder contact so a stylus responds more accurately. Resistive touch screens are great for handwriting recognition with a stylus. Newhaven Display offers many size options for our resistive touch panels including 128x160, 240x320, 480x272, 640x480 and 800x480 pixels. The resistive touch panel is made up of several layers. When you press down onto the touch panel with your finger or stylus, the top layer flexes and pushes back onto a layer behind it. This will effectively complete a circuit and tell the controller which part of the touch panel is being pressed.
Key Features and Advantages
Can operate with pointing devices like stylus, pen, nail, gloved finger...etc.
Sizes fit 1.8", 2.4", 3.5", 4.3", 5.0", 5.7", 7.0" TFTs
Can operate at any level of humidity
3H hardness, >1 million touches