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Melrose Nameplate & Label Co. All Rights Reserved.
26575 Corporate Avenue
Hayward, CA 94545
510-732-3100
FAX: 510-732-3111
- Failure Due to Damage: 4-wire touch screens will not function if the top layer is penetrated or fails due to fatigue.
- Drift: A 4-wire touch system may experience voltage losses due resistance changes in the bus bars and connection between the controller and sensor. The losses can vary with product use, temperature, and humidity. In a 4-wire sensor, variations in the losses manifest themselves as error or drift in the reported touch location.
- Incorporating a membrane switch or graphic overlay protects the functional top layer of a 4-wire switch from damange.
- 8-wire touch screens eliminate drift inherent in 4-wire. 8-wire screens incorporate 4 extra wires that enable the controller to correct for drift caused by temperature and humidity variatiions. Like a 4-wire, the top layer should be protected from abuse as it is a functioning part of the touch screen mechanism. Top layer protection can be with graphic overlay or membrane switch.
- 5-wire touch screens allow top layer damage that would render 4-wire nonfunctional. 4-wire damage may occur due to PET fatigue, or mechanical abuse. Function continues because the 5-wire's essential circuitry is on the lower layer.
Melrose engineers and manufactures touch screens with resistive technologies.
- low cost 4-wire
- more reliable 5 and 8-wire
- easily interfaced touch matrix
4-wire touch screen issues. Customers are attracted by 4-wire touch screens because of their low cost. However 4-wire touch screens have two limitations to consider:
4-wire issue mitigation. 4-wire drift and failure due to top layer damage can be mitigated in one of three ways.
4, 8 and 5-wire resistive touch screens consist of a flexible top layer (PET) and a bottom layer (glass or PET), separated by tiny spacer dots. The inside surface of each layer is finished with a transparent conductive coating (ITO). Touch creates contact between the top and bottom circuit layers. The touch screen’s controller applies a linear voltage gradient across a layer. The x-coordinate is measured on the opposing layer. The y-coordinate is measured by reversing the the function of the layers. 5 wire and 8 wire touch screens mitigate the two major issues inherent in 4-wire panels.
Matrix Touch Screens require no controller as they interface with the computer just like membrane switches. Matrix touch screens consist of ITO-coated top and bottom layers separated by spacer dots. The ITO coating is etched to form rows on one layer and columns on the other. The rows & columns terminate on the tail and are read by the controller like a membrane switch. When touched, the top layer completes a circuit with the bottom layer. The row column configuration can be defined by the customer to meet application requirements.
More on touch screens
- Standalone touchscreen
Engineering
- Touchscreen types
4, 5 and 8 Wire Resistive and Matrix Touch Screens
Melrose engineers are available to discuss your touch screen application from 6am to 5pm Pacfic (M-F). Please call 800-826-7741 or e-mail to contact one.
Click On Image For Englarged View and Description
Melrose engineers are available to discuss touch screen trade-offs from 6am to 5pm Pacific (M-F). Please call 800-826-7741 or e-mail to contact and engineeer.
Melrose engineers are available to discuss touch screen trade-offs from 6am to 5pm Pacific (M-F). Please call 800-826-7741 or e-mail to contact and engineeer.
