JHC Sealing Solutions is a supplier for optical enhancement solutions. Whether for simple anti-reflective matter removable films to full ruggedised touchscreen integrated EMI shielding laminated glass displays, JHC can assist with application advice and product supply.
Some of JHC’s product solutions include:
- EMI shielding
- Transparent heaters
- Sunlight readability and stray light control
- Impact resistance and ruggedisation
- Touch screen integration and enhancement
- Night vision compatability
- Micro-louver privacy filters
To provide some initial guidance, the following lists some of the types of filters that JHC recommends for different display types:
- Electro-luminescent displays - These are one-colour bright displays. EMI can radiate from the electronics behind the display. On sensitive devices the display needs to be shielded. Plastic or glass windows can be used. Moir fringing is not an issue on these displays so the mesh can be set at 90. A circular polariser is usually included in the laminate to eliminate reflections from the metal components of the display
- LCDs - This is a pixel based display with electro-magnetic interference emanating from the electronic circuitry itself. While much of this electro-magnetic interference can be controlled at the board level, in some cases it may be necessary to shield the whole appliance, including putting a shielded window over the display aperture. There are two options for shielding these displays: conductive coatings and wire mesh windows
- PDPs - This is the only display type where the emi emanates from the display itself and not the circuitry. It is therefore essential that the window area is shielded as the interference can not be controlled at board level. Issues for consideration are; light transmission, shielding to Class B EN5044:1, NIR (Near Infra-Red) blocking when remote devices are used, surface reflections and cost
- LEDs - These are usually one colour displays. They can be bright and there is usually a requirement for contrast enhancement. Using a coloured filter or neutral density filter will enhance the actual LEDs while attenuating the other colours and making the back of the display appear darker.
- CRTs - Many CRT displays are produced with a fine etched surface. Using a filter with a non-glare surface (another etched surface) produces a coloured sparkling effect when viewing the CRT through this filter. This can be dealt with by moving the filter further away from the CRT or by changing to an anti-reflective optical coating. For office or bank use where confidentiality is an issue, a privacy film can be included in the laminate. This controls the viewing angle of the display.
- Touchscreens - Now being used in a wide range of applications from offices to ATMs, public information displays to gaming machines. Given the nature of these applications, these screens are often treated roughly and it is therefore important that they provide a reasonable level of impact resistance and safety. If they were to break, the screen should remain intact, thus avoiding damage to the equipment and to persons from broken glass
- Security glass - Full lamination of the sensor glass with another piece of glass or plastic can enhance the overall strength and safety of the screen without impairing the optical clarity of the display
- Privacy filters - Touchscreens are being increasingly used on ATM machines where privacy is an important consideration. Light control films such as 3M privacy filters, can be used to control the angle from which the display can be viewed