The ICDM (International Committee for Display Metrology) and SID (Society for Information Display) have published a very comprehensive set of standards for measuring display characteristics.
It is very impressive and available for free download at http://www.icdm-sid.org/, well worth a look for anyone who wants to know more about display specifications and their measurement.
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The IR board is one of those small accessories that sometimes gets overlooked but plays a valuable role. A pictured below this small board is designed to be integrated on the inside of an enclosure with suitable access holes.
The IR receiver is used for the On Screen Display (OSD) menu of Digital View display interface controllers and works with the Digital View remote control. The LED is the controller power indicator.
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At the SID display exhibition in Boston 5-7 June we will be announcing the latest HD-SDI interface now with a fiber interface, the HD-3000SF. In addition to the standard BNC connectors the HD-3000SF also supports a standard SFP fiber module providing distance driving – so far verified over 1.5km.
Picture shows SFP module with passthrough.
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Back in 2001 Captive View (a Digital View joint venture) launched a washroom media product called the Viewrinal, an LCD display built into a urinal. The Viewrinal was successfully installed in a number of venues, most notably a few nightclubs in London, UK, and also caught some good media attention. Captive View was sold during 2003 and since then the concept has resurfaced many times with other companies – most recently with Sega and their Toylets, see http://toylets.sega.jp/
Color is an involved topic but in the context of LCD panel selection there are generally two main parameters specified:
- Color depth: This represents how many colors a panel is technical capable of showing within its color gamut. LCD panels mostly comprise 3 colors R (red), G (green), B (blue) so the number of shades possible for each color indicates the theoretical number of colors. See table.
- Color gamut: This refers to the range of colors a panel is able to show out of the visible spectrum, it is typically represented on a 3 coordinate color map. Typical color-space references are NTSC, Rec. 601 and Rec.709, the color gamut will be the extent (as a %) to which a panel is able to achieve the color-space reference.
For most industrial applications the color depth is unlikely to be particularly important. For applications where video or images are shown, particularly of things like the sky or skin, a greater color depth should enable a smoother looking image without noticeable steps between color shades. This of course depends on other parts of the display system being up to the same standard.
Color gamut will be considered further in a later blog.
If you are planning a digital signage display system the following LCD controllers are a great place to begin:
- SVX-1920, the most popular choice as it offers a significant number of functions and control options together with support for DisplayMark display and system monitoring as well as support for 120Hz panels when used with the IE-1000 add-on board.
- ALR-1920, when straightforward full-screen video is required and cost is a key factor the ALR-1920 is a great choice. It is compact and easy to work with and gives excellent results.
- SGX-1920, this is the very top of the range providing all the features of the SVA-1920 plus a considerable number of input signal options as well dual digital input and powerful Picture in Picture capabilities.
For details of all Digital View controllers see www.digitalview.com/display-builder-home, this also provides details of complementary accessories.
The Digital View reseller web page has been updated, all resellers are now shown on a single page to make it easier to find a local supplier.
This can be seen at: http://www.digitalview.com/resellers
Various display resolutions have been given names, the list below shows what I feel are the most common names with the respective resolutions – there are are plenty more but they are not in common usage:
- QVGA: 320 x 240
- VGA: 640 x 480 (VGA is also used a generic name for the ARGB input)
- SVGA: 800 x 600
- XGA: 1024 x 768
- WXGA: 1280 x 768
- SXGA: 1280 x 1024
- UXGA: 1600 x 1200
- WUXGA: 1920 x 1200
- WQXGA: 2560 x 1600
Personally I prefer to stick with the actual resolution, it is less ambiguous.
If you are looking for information about displays and related technologies Veritas et Visus newsletters are a good place to start. See: http://www.veritasetvisus.com/
In addition to commentary the newsletters also include new product announcements and relevant trade event coverage.
Digital View have been exhibiting at SID since 1996 – this year it is being held in Boston from 5-7 June 2012 and we will be there again.
This year we will be showcasing new harsh environment solutions, connectivity options as well as systems for video-wall developers. We will also have some add-on accessories for signage display developers.
Digital View SID 2011
The ‘Autobright+’ sensor board (pictured) changes LCD contrast and black-level to preset levels according to ambient light conditions. It also recognizes RS-232 commands for remote control of these settings. This kind of setting adjustment is useful for low light conditions.
It is an example of one of the many add-ons and product extensions that add value to a display system.
Digital View works with the following inverter and LED driver manufacturers:
- Endicott Research Group
- Applied Concepts
- JKL Components
- Quantum Engineering Corp
More details are provided on the website at www.digitalview.com/inverter-partners
The viewing angle of an LCD panel is generally expressed for both horizontal and vertical in degrees from perpendicular to the display or as a total of left & right and up & down. So for example the newer IPS panels now claim up to 178 degree viewing angle.
A few important points to note with viewing angle:
- As I am likely to mention for other specifications it is difficult to choose a panel solely on specification, it is worth seeing the panel. I have seen a panel with excellent viewing angle ratings but when testing it I found a color shift at around 45 degrees from perpendicular.
- Specifications are generally expressed for the panel in landscape orientation so if the panel is going to be used in portrait mode the up/down viewing angle in the specification will be very relevant.
- TN type TFT panels may only offer a viewing angle of 130 degrees with different up/down results making them unsuitable for portrait mode.
Overall viewing angle is becoming less of an issue as there are panel choices to meet the requirements of most users.
In the commercial and professional market display systems differ in many significant respects and are far from the commoditization of the consumer monitor market. The differences are both external and internal:
- Panel choice: Brightness and temperature range are two obvious and significant factors as well as color, resolution, viewing angle and even shape.
- Enclosure design: Size, shape, ruggedness and controls.
- User interface: Very likely to be quite different with presets for specific functions, different type of controls such as a joystick or remote activation.
- Signal inputs: Aside from standards such as HD-SDI there are many custom signal requirements.
- Power supply: Especially in transport and industrial equipment display systems are likely to have different power supply requirements.
- Environmental: Resilience against dust, humidity and other that require conformal coated electronics.
- Compliance: A major factor can be the specific compliance requirements for a market application such as for medical or commercial marine.
- Lifetime & Lifecycle: Not just operating lifetime but also the production lifecycle of the components – we often have to supply the same LCD controller for over 5 years.
The above are just some headline differences but provide a clear indication how many permutations of display system design there can be to meet different niche market requirements. It is an exciting market with considerable scope for creativity and innovation.
The Hong Kong Heritage Museum kindly sent over some photos of recent installations using Digital View VideoStream media players and VideoFlyers.