So you’ve been tasked with implementing a digital signage solution, and it’s time to shop for displays. Well, in addition to selecting a screen size, you’ll need to select the type of flat-panel technology to use. There are three types of flat-panel displays currently available from commercial display companies. These are LCD, LED and OLED. There are distinct differences between them.
LCD (CCFL) Displays
LCD (CCFL) displays have been the most widely used type of display for signage up until recently. It is a method of backlighting using a panel of CCFL lamps placed behind two panels of glass filled with liquid crystal matter, which becomes opaque when an electric current passes through it. The contrast between the opaque and transparent areas forms visible characters. LCD displays are generally less expensive, wider in depth and weigh more than LED displays.
LED back-lit LCDs are a step up from LCD (CCFL) panels, and are offered in different varieties: back-lit, edge-lit and direct-lit. LED types use either a matrix of LEDs behind the screen, or an array of side-mounted LEDs to replace the cold cathode fluorescent light lamps (CCFLs). Although the concept is generally the same as CCFL backlighting, the differences in performance are significant. LEDs can be switched on and off more quickly than CCFL displays, and can typically offer a brighter screen.
LED displays are sharper, clearer and offer brighter colors and better contrast over LCD. LEDs also offer lower operating costs by using up to 50 percent less power consumption than CCFLs. LEDs offer a slimmer profile, with some commercial displays being less than a few millimeters in depth against up to 5 inches with CCFL displays. Because of the many advantages and energy savings, manufacturers have started to discontinue CCFL displays in favor of LEDs.
An organic light-emitting diode (OLED) is an organic LED, similar to a regular LED, except that it is made up of organic semiconductor material. This organic material is sandwiched between two electrodes, and produces light when current is made to flow through its volume. The active material is thinner than a regular LED. An OLED does not require a backlight. OLED displays produce deeper blacks and brighter whites.
Because OLED doesn’t use a backlight, display manufacturers are starting to show displays that could be bent or rolled up. LG recently introduced an 18-inch display that can be rolled up, and is working on larger roll-up sizes. LG also recently announced a 55-inch and 65-inch double-sided OLED. Expect many new and unique display technologies using OLED for retail applications.