Starting from the great experience accumulated with TFT displays, EDT has studied and developed proprietary touch panel solutions. Through the adoption of different construction technologies, it has made models from 3.5" to 15.4" single and multi-touch models of excellent workmanship and quality. We also offer finished products complete with customizable protective cover lens.
You can follow some lessons about the capacitive touch panel technology and an overview of EDT products.
Please contact us for further infos.
The base structure of the capacitive panel consists of two parts: touch sensor and cover lens. There are two types of touch sensors. First, we have the glass sensor that benefits from optical performance, durability and tight boundary, so the film sensor has the advantages of subtility, lightness and ease of production.
There are two types of cover lens: glass and plastic. The typical thickness of the cover lens ranges from 0.55, 0.75 or 1.1 mm to mobile devices and reaches up to 3 mm or more for industrial applications. The dielectric constant of the cover lens and its thickness have a direct impact on the sensitivity of the capacitive touch panels: a slimmer coverage lens and/or a higher dielectric constant allow for better performance. Plastic (PMMA) has a lower dielectric constant and must be half the thickness of the glass to achieve the same performance.
EDT develops various types of sensor and cover lens combination for the capacitive touch panels: Glass to Glass, Glass to film and One Glass only. The followings are our available capacitive touch panel structures.
Following the continuous evolving demand for advanced user interfaces, EDT is proud to present the latest innovation in the field of capacitive tactile technologies. It features EDT PolyTouch™ capacitive touch solution, alternative to common touch sensory design, easy to deploy and highly reliable. Unlike traditional resistive touch panels, EDT PolyTouch™ Uses an exclusive structural design that omits the need for sensory films and allows for a much more durable product and a wider range of use. With various functions and pre-installed controls, each PolyTouch™ Can be easily integrated and made compatible with both existing and newly-conceived systems for rapid deployment and development. The standard EDT project offers single touch and multi-touch options. Both can be customized and integrated into the display project. Compatible with TFT, Monochrome and CSTN displays, the EDT PolyTouch™ Is the perfect solution for excellent visualization and interaction with the user.
The Glass/Glass (G/G) type capacitive touch panel (CTP) has been used for glass cover lens laminated with glass sensor.
The cover glass is used to protect the sensor glass underneath, and the sensor glass is used to sense the touch points. The sensor glass is coated with two conductive layers of ITO: one for the x-axis, another for the y-axis. There are two types of G/G solutions: double-sided indium-tin oxide (DITO), patented by Apple, and single-sided ITO (SITO) that is the most popular used in the CTP industry.
The overall thickness of EDT’s G/G type CTP can be from 1.1 mm for portable device to 3.5 mm or even thicker for various industrial applications. Advantage for G/G type CTP is that the glass cover lens can be custom made by screprinted on the rear surface, in-mold decorated (IMD), complex treatment with multiple holes and slots, rounded corners, even bent edges, and in most cases, chemically strengthen to enhance its resistance to external impact.
First, applying a chemical strengthening process onto mother glass, followed by the application of blackmasking (BM1) and circuitry layout. Once circuitry is completed, mother glass is then divided into individual size panels, and applied with edge-grinding treatment. A second step of chemical strengthening process is then applied, followed by optional decoration printing or surface treatment.
Individual panels are separated from the mother glass and undergone chemical strengthening individually. The glass is then entered cover lens and blackmasking (BM) process, followed by circuitry application and at last any pattern decoration or surface treatment.
EDT’s G1F structure is optimized from G-G and G-F-F. It is composed of one glass sensor, which is made from cover glass and one film sensor. G1F improves thickness and weight of G-G, and also the optical performance of G-F-F.
Common thickness: 150μm, 175μm, 200μm, 250μm, 500μm, 800μm
Optical bonding is the process of laminating cover glass or touchscreens to the LCD cell. It is a process that applies a layer of transparent material such as OCA (Optically Clear Adhesive) or OCR (Optically Clear Resin) between the layers to completely fill the air gap. The adhesive is completely transparent, the structure and color of the adhesive will not transform through the use of time. Any display in an outdoor environment or high ambient light conditions can be improved with our matured technology and experience. EDT provides optical bonding solutions to a wide variety of applications like handheld device for outdoor use, navigation systems, industrial, medical displays, and ATM equipment, for clear visibility under sunlight or in bright environment.
Optical bonding has some the following advantages,
For air gap structure with AR(R1=0.5%), the total specular reflectance is 8.5%, the CR can be calculated below, and it should be larger than the structure without AR.
For optical bonding(R2+3=0.2%) structure without AR, the total specular reflectance is 4.2%, the CR can be calculated below,
When surrounding glare makes display readability difficult, anti-glare (AG) coatings utilize diffusive properties to fragment the ambient light
off the surface, using the concept of constructive interference of light. Diffusion works by scattering specular reflections into a wide viewing
cone, making these undesirable reflected images and glare blurred to the eye
AG coatings use either diffused particles or etching on the glass surface and can enhance viewing performance. EDT currently provides
one standard types of AG coating, both with superior glare reduction for glass cover lens.
Using the concept of destructive interference of light, anti-reflective (AR) coatings utilize stacking layers structure over the glass
surfaces that vastly improve the efficiency of the optical performance by increasing transmission, enhancing contrast, and eliminating
ghost images.
1. The transmission rate could reach up to 92% for single side one layer AR coating and 94% for double side two layers AR coating.
2. AR coating is vulnerable against finger prints, therefore extra layer of AF costing is always required.
Anti-Fingerprint (AF) coating is using nano-scale material which has excellent water & oil repellency to make the glass surface having smooth touch, and prevent glass surface from contamination such as smudging or staining, making the glass surface extra slippery and easy to clean.
