A touch screen is a machine interface that is sensitive to touch. Many cash withdrawal (banking) machines utilize touch screen technology. The touch screen is a clear panel that mounts in front of an LCD display. We can print legends or other text directly on the glass if needed. RSP supplies touch screens and LCD assemblies.

Standard touch screens are rigid (glass) but they can also be flexible. The operating temperature is approximately -10ºC – 70ºC (14ºF – 150ºF).

Digital Resistive Touch Screen

This type of touch screen is sometimes referred to as the X-Y matrix touch screen. It has a projected life of 1 million actuations.

The typical border width is at least .25”.  Digital resistive touch screens operate by decoding or measuring a

direct resistive circuit. There are four layers;

1. Top polyester layer coated with a conductive coating

2. Adhesive spacer

3. Glass layer coated with a conductive coating

4. Adhesive layer on the backside of the glass for mounting.

Advantages

• No false actuations
• Low cost
• Easily adapted tp various sizes (1”x1” minimun ) and configurations
• Able to be sealed to NEMA-4 specifications

Disadvantages

• Limited number of touch points
• Mechanical wear, top layer can be scratched
• Glass layer can break

To produce digital resistive touch screens conductive coating is either etched away or selectively applied to form rows on one layer and columns on the opposite layer. When assembled, the rows and columns form a matrix of switches. The location of each switch is permanent. The resolution of the touch screen depends upon the number or rows and columns specified.

 
Analog touch screens have one layer that carries the X axis and one layer that carries the Y axis. The axes are determined by the orientation of bus bars printed on two opposite edges of each layer. Both axes must remain perfectly linear in order for the touch screen to function properly. When the two conductive coated layers are placed together it forms a single switch. An analog switch is activated no matter where the screen is touched. The controller detects the location of the touch based on the voltage drop sensed in each layer at the point where they make contact.

Unlike digital touch screens which require a pin connector for each row and column, analog models can be attached to the controller with either a 4-pin or 5-pin connector.  The standard 4-wire analog touch screens have a projected life of approximately 1 million actuations.  Typical border widths are .15”.  There are four layers:

1. Top polyester layer coated with conductive film

2. Adhesive spacer

3. Glass layer coated with a conductive film

4. Adhesive layer for mounting

The 5-wire analog touch screens have a projected life of approximately 35 million actuations.

Typical border widths are .25”. There are six layers:

1. Top polyester layer coated with conductive film

2. Adhesive

3. Polyester spacer

4. Adhesive

5. Glass layer coated with a conductive film

6. Adhesive layer for mounting

Printed spacer dots on the glass layer are used for controlling the actuation force and to keep the

conductive layers from premature contact.

Advantages

• No false actuations
• 4096 x 4096 touch points
• No stylus needed, operates with a gloved finger
• Able to be sealed to NEMA-4 specifications

Disadvantages

• Maximum transmissivity of 80%
• Mechanical wear, top layer can be scratched
• Glass layer can break

Analog Resistive Touch Screen

This type of touch screen is designed for ‘pen recognition’ and other applications where a higher resolution is required than is feasible with a digital resistive touch screen.

Analog touch screens have one layer that carries the X axis and one layer that carries the Y axis. The axes are determined by the orientation of bus bars printed on two opposite edges of each layer. Both axes must remain perfectly linear in order for the touch screen to function properly. When the two
conductive coated layers are placed together it forms a single switch. An analog switch is activated no matter where the screen is touched. The controller detects the location of the touch based on the voltage drop sensed in each layer at the point where they make contact.

Unlike digital touch screens which require a pin connector for each row and column, analog models can be attached to the controller with either a 4-pin or 5-pin connector.

4-wire analog touch screens have a projected life of approximately 1 million actuations. Typical border widths are .15”. There are four layers:

1. Top polyester layer coated with conductive film
2. Adhesive spacer
3. Glass layer coated with a conductive film
4. Adhesive layer for mounting

Advantages

• No false actuations
• 4096 x 4096 touch points
• No stylus needed, operates with a gloved finger
• Able to be sealed to NEMA
  

Disadvantages

• Maximum transmissivity of 80%
• Mechanical wear, top layer can be scratched
• Glass layer can break

• No false actuations
• 4096 x 4096 touch points
• No stylus needed, operates with a gloved finger
• Able to be sealed to NEMA
• Rated for 35 million actuations
  

Disadvantages

• Maximum transmissivity of 80%
• Mechanical wear, top layer can be scratched
• Glass layer can break