This provides an overview of the LCD monitor nomenclature and specifications as they relate to TRU-Vuindustrial monitors.This is an ever changing industry and as such, all specifications are subject to change.Only LCD displays will be covered in this paper; CRT's, LED's and Plasma are not considered.
LCD TECHNOLOGY
The LCD monitor represents the display technology of choice for most industrial, commercial, medical, law enforcement and military applications.LCD offers the best compromise between performance, price, and reliability.
LCD stands for Liquid Crystal Display. It utilizes liquid crystals sandwiched between two layers of glass, that when energized allow light to pass through. In the "off" state, a liquid crystal will block light. Think of an LCD as a shutter that controls the passage of light. There is a fluorescent or LED backlight behind the LCD that is constantly on. The light from the backlight is passed through the LCD module, where the amount of light modulated by each individual pixel to create various level of brightness. In the front pane of glass are color filters. These are vertical strips of Red, Green, and Blue that when combined form a pixel and can produce any color of the spectrum. White is achieved by opening all colors, black by blocking all colors. The location of each individual Pixel is fixed with an LCD, as compared with a CRT where the pixel location is determined by the location of the electron beam.
Advantages:
Will not burn-in the image.This is critical when viewing static images
Thin and lightweight
Perfect geometry of the image
Superior focus across the entire image
Reliability
COMPONENTS OF AN LCD DISPLAY
Compared with a CRT monitor, the LCD display is a much simpler device.This relates to less components used and therefore higher reliability.
LCD Module The glass display window.This is a light shutter that varies the amount of light allowed through a given color of sub-pixel to create an overall image.There are approximately six major manufacturers of LCD modules, with another half-dozen smaller, specialized LCD producers.The LCD module typically includes the backlight as part of a complete assembly.All LCD modules have polarizers to direct the light, and diffusers to eliminate bright spots where the lamps are.
Backlight The light source behind the LCD Shutter.This is typically made of CCFL fluorescent lamps or an array of LED"s.There are Direct backlight and Edge backlight configurations.Most backlights are CCFL Fluorescent, but LED"s are making in roads.
Inverter An electronic ballast to drive the fluorescent lamps of the LCD module.A high-voltage, low current device, it is critical that the inverter be matched to the LCD for maximum lamp life. Controller Board The brains of the unit.The controller board converts either an analog or digital signal from the camera/computer to the digital signal the LCD module requires.This board also controls all other aspects of the signal and display quality such as the On Screen Display function, Scaling, and audio when optioned.
OSD Board On Screen Display board.Switch board to control the parameters of the display such as power, brightness, contrast, color, sizing, volume, etc.
Power Supply LCD's are typically powered internally by 12 or 24 VDC.To operate the display, an AC/DC transformer is required.The transformer can be either internal or external to the display.An external transformer would be the "Power Brick" that is common on smaller sized displays, while the internal style would have an IEC-320 style plug that connects directly to a wall outlet.There are advantages to both types; the external does not induce heat to the monitor, while the internal is more convenient. RESOLUTION
The resolution of the display is determined by the quantity of horizontal and vertical pixels.An LCD has a "Native" resolution, which is the fixed quantity of horizontal and vertical pixels.Through scaling of the graphics chip, the LCD can display many resolutions other than the native resolution.For example, when the signal source is putting out 640x480 resolution on a 15" LCD (native is 1024x768), it will expand the image to fill the entire screen rather than showing a reduced size image in the center of the screen.There are VESA standards of resolution that are typically used for display properties.Occasionally, there will be proprietary signals that are not compatible with standard LCD products.These proprietary signals can be especially difficult for an LCD to resolve.Due to the LCD using digital logic, they typically require a very structured signal and are not as forgiving as the analog CRT's were.
VESA Standard Resolutions (and typical associated panel sizes):
VGA:640 x 480 pixels8" and smaller, some 20" SVGA:800 x 6008.4", 10", 10.4", 12", some 20" XGA:1024 x 76815" WXGA:1280 x 76817" WXGA:1366 x 76818.5", 20", 23", 26", 32", 37", 42" WXGA+:1440 x 90019" SXGA:1280 x 102417", 19" WSXGA+:1680 x 105020", 22" UXGA:1600 x 120020" FULL HD:1920 x 1080 26", 32", 42", 46", 52"
These represent the standard sizes as dictated by VESA (Video Electronics Standard Assoc.), There are others available in specialty markets.Often the resolution will be referred to as X mega-pixels (MP); this refers to the quantity of total pixels on the display in millions, multiplying the Horizontal x Vertical.Example SXGA = 1280 (H) x 1024 (V), or 1.3MP.UXGA is 1600 x 1200, or 2MP.
ASPECT RATIO
There are two basic aspect ratios available:4:3 (standard) and 16:9 (widescreen).The standard aspect ratio displays are being replaced by the widescreen aspect ratio displays, driven by the HD television market.Standard aspect ratio displays are only available in sizes of 20.1" and smaller.Widescreen aspect ratio displays are available across the size spectrum.
VIDEO CONNECTIONS
There are different input connections for LCD monitors, typically associated with given resolutions.There are other, less common connectors, but these are the most prevalent in the industry.
Composite(CVBS-Composite Video Blanking and Sync) RCA and BNC connectors. Typically associated with NTSC, PAL, and SECAM low resolution, interlaced signals.Has video, color, and sync signals combined in one carrier.
S-Video(Separate Video)Four-Pin Mini-Din connector.An analog signal that separates the Brightness and Color components of the video signal. Slightly better than CVBS for image quality, associated with NTSC, PAL, and SECAM interlaced signals.
VGA(Video Graphics Array)Standard computer monitor interface.HD-15 D-Sub connector.Analog signal capable of running from VGA through UXGA.Utilizes separate R,G,B color and Horizontal and Vertical sync signals.
DVI-D(Digital Visual Interface- Digital)24-Pin D-shaped connector, compatible with DVI-I connector from a mechanical standpoint.Pure digital signal, no analog component transmitted.Not as common as the DVI-I signal due to the universality of the DVI-I signal.
DVI-I(Digital Visual Interface- Integrated) 27-Pin D-shaped connector.This has both the digital and analog components of the signal.The analog portion allows the signal to work with VGA connections when an adaptor is used.
HDMI(Hi-Definition Multimedia Interface) 19-Pin connector, similar in size to a USB connector.UncompressedDigital signal for video and audio. Capable of displaying up to Full HD signals. Typically used in consumer HD applications.
SDI(Serial Digital Interface)BNC connector. Digital signal used in Broadcast industry.
HD-SDI (Hi-Definition Serial Digital Interface) BNC connector.Used for Hi-Def Broadcast signals.
YCbCr (Color Component Video) Uses a 6-pin Mini-Din connector, or 3RCA connectors. The digital signal is separated into Y (the luma/brightness), Cb (the blue minus luma) and Cr (red minus luma). The difference between YCbCr and RGB is that YCbCr represents brightness and two color difference signals, while RGB represents color as red, green and blue. YbCbCr takes advantage of the fact that the eye is more discriminating of brightness than color.
FACE TREATMENT There are two types of face treatment on LCD panels; Standard (non-glare) and Glare type.The
standard will diffuse ambient light reflections at the cost of
decreased contrast, while the Glare type will improve contrast, but at
the cost of higher reflections.
MOUNTING
LCD monitors use VESA mounting patterns.These standard mounting patterns allow compatibility between the various monitor and hardware manufacturers.
TRU-Vu Mounting patterns: 75mm x 75mm12", 19"; 100mm x 100mm20", 42"; 200mm x 100mm26", 42". Above patterns all use 4mm screwsThe larger displays (32"+) also utilize a method of mounting directly to the LCD module.The patterns are various, but mount manufacturers have universal mounts that adjust to meet these patterns. TRU-Vu SPECIFIES:
TRU-VuPROTECTIVE GLASS
TRU-Vu monitors offers a unique protective glass panel for their LCD monitors.This panel is Anti-Reflective (A/R) on both sides to reduce internal reflections as well as external. Bonded panel technology:On smaller sized products, we can also offer a bonded panel technology.This is a process of injecting an epoxy resin between the LCD face and the glass protective panel.This technology vastly improves contrast and high ambient light readability.
REMOTE CONTROL TRU-Vu monitors 20" and larger include Remote Controls.This allows all aspects of the monitor to be adjusted through the remote.There are two remote configurations used depending on the model of display.
24VDC OPERATION
TRU-Vu monitors 20" and larger operate on 24vdc.This allows an external power supply to be mounted a distance away from the display.By
remotely mounting the power supply, there are large savings in
installation costs when the display is to be located in an area where AC
power is not readily available.24VDC operation allows smaller gauge wire to be run to the display versus 12VDC operation.
ASPECT CORRECTION TheTRU-Vu
widescreen displays have a Aspect Correction feature to display the
correct aspect ratio of a 4:3 camera image on a 16:9 display.This feature does not distort the image horizontally to fill the screen width.This is unique to TRU-Vu monitors.
SERVICE
WhileTRU-Vu monitors are extremely reliable, there could be an occasional problem.All Tru-Vu display products are serviced by Clinton Electronics in Rockford, IL.Turn around time is typically less than one week, and advanced replacement products are often available.
TECHNICAL SUPPORT
TheTRU-Vu
Technical Support team is comprised of technicians who have an average
tenure with Clinton Electronics of over 10 years in the
Engineering/Technical Department.When you call with a question, the techs are on site and know the product first-hand.
CUSTOM PRODUCTS
With our vast inventory of available options and engineering capabilities, we can provide custom TRU-Vu monitors
with all the features and functionality you need, at very competitive
prices. LCD panels, enclosures, video connections, special features,
private-labeling, custom mounting, and integrated accessory devices are
all available to meet your OEM requirements.
