Video Electronics Standards Association
| Video Electronics Standards Association (VESA) |
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| purpose | Development and promotion of technical standards |
| Seat | San Jose , USA |
| founding | November 1988
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| Organization type | Non-profit corporation |
| Website | www.VESA.org |
The Video Electronics Standards Association ( VESA ) is an organization in which around 270+ member companies (as of August 2018) have come together to create uniform specifications of video standards especially for the field of computer graphics . It is considered one of the largest industrial standardization organizations. Above all , she regularly participates in the annual SIGGRAPH conference series with numerous lectures.
history
The Video Electronics Standards Association was founded in 1988 by NEC Home Electronics , a large producer of MultiSync monitors and eight graphics card manufacturers: ATI Technologies , Genoa Systems , Orchid Technology, Renaissance GRX, STB Systems, Tecmar, Video 7 and Western Digital / Paradise Systems.
Various types of computers and graphics standards existed in the 1980s, nearly each of which required a compatible screen or at least a suitable adapter. VESA came up with the idea of standardizing the interface between computer and screen; so the two devices could develop independently of each other. The original goal of the organization was primarily to establish an industry standard for the emerging SVGA screen resolution of 800 × 600 pixels . VESA achieved greater popularity primarily through its specification of the VESA BIOS Extension and the VESA Local Bus (VLB) for IBM PC- compatible computers. With DPMS , Video Input Port (VIP) and DFP technologies, further fields of activity soon arose for VESA.
Furthermore, by defining the so-called VESA modes for the timing of the screen control signals and the associated General Timing Formula (GTF), VESA is still of great importance for the standardization of parts of computer technology. In addition, the DDC ( Display Data Channel ) standard and the associated Extended Display Identification Data (EDID) specification were laid down by VESA. The standardization of DVI-D and DVI-I connection techniques for digital video data was also involved. Newer standards such as HDTV are also likely to be influenced by the VESA. Proposals for standardization from August 2005 propagate the DisplayPort , which is based on PCI Express technologies. Similar to HDMI , high-resolution video and audio signals can be encrypted and transmitted uncompressed via a single cable to a screen .
In November 2010, the merger declared a cooperation with the Wireless Gigabit Alliance (WiGig) in order to jointly develop the standards for the wireless DisplayPort . After WiGig was merged into the WI-Fi Alliance in 2013, VESA and WI-Fi Alliance announced the continuation of their cooperation, initially primarily to further develop 60 GHz technology.
VESA standards
Display timings
In order for the computer sending the video signal and the screen receiving the video signal to understand each other, both sides need to use a signal that follows the same timing rules.
Display Monitor Timing (DMT)
In the first approach of a VESA standard, a list of image resolutions , color depths and refresh rates was created, which contains the respective time values - the timing. Despite a newer method of a formula for the dynamic calculation of the timing, this list called Display Monitor Timing is still maintained by the VESA. In mid-2014, the latest DMT edition was “Revision 13” from March 2013.
General Timing Formula (GTF)
The screen industry developed rapidly. Instead of building screens with fixed timings, the control of the CRT screens became more flexible and allowed a variety of different resolutions. Instead of including all possible resolutions and timings in the DMT table, VESA began to market a formula in 1996 that made it possible to calculate the required timings from a desired resolution and refresh rate.
The General Timing Formula took into account the technological framework conditions known at the time. For example, the horizontal resolution must be divisible by eight, the horizontal synchronization pulse should be eight percent of the screen line length.
The GTF specification is not freely available. An open source program, however, is able to calculate the timing according to GTF.
Coordinated Video Timings (CVT)
The screen industry continued to advance. The tube screens have increasingly been replaced by LCD or plasma screens. At the end of the picture, the tube screens needed a certain amount of time until the electron beam had moved from the bottom right to the top left. This pause, known as the blanking interval , is technically superfluous with LCD screens and can be saved with reduced blanking .
Information technology and entertainment technology merged more and more: With the digitization of televisions, the image resolutions used there (720p, 1080i, ...) and aspect ratios (e.g. 16: 9 instead of the 4: 3 previously widespread in the IT world) interesting for the IT industry. Therefore, in 2003, VESA decided to adapt the GTF to the new conditions and designed a refined CVT formula based on GTF.
CVT encodes the aspect ratio into the signal (the length of the vertical synchronization pulse indicates the aspect ratio, e.g. 4 lines → 4: 3, 5 lines → 16: 9 ...), and whether the video signal uses "normal" tube blanking times or shortened LCD Blanking times, is controlled by the polarity of the sync pulses (H- / V + → normal, H + / V- → shortened)
The CVT specification is not freely available. However, an open source program is able to calculate the video timings according to CVT (and GTF).
future
Even CVT still has the limitation that the horizontal resolution must be divisible by eight. At the moment, this could be circumvented by including these new resolutions in the DMT table. If not only video but also audio signals are to be transmitted with the signal, the calculated video timings are not optimally compatible with the timings used in the audio world. The latest developments take this into account by also taking into account the new requirements and framework conditions.
Connections / hardware interfaces
- VESA Feature Connector (VFC)
- VESA Advanced Feature Connector (VAFC)
- VESA Enhanced Video Connector
- VESA Local Bus (VLB)
- VESA stereo
- VESA Video Interface Port (VIP)
- DisplayPort
VESA mounts (screen mounts)
The VESA Flat Display Mounting Interface (FDMI) is a standard for attaching flat screens to walls, ceilings, tables or vehicles, which, depending on the dimensions and weight of the screen, provides at least 4 threads for metric screws: Until October 2002 this standardization was called Flat Panel Monitor Physical Mounting Interface (FPMPMI).
The variants of the FDMI are diverse and start with four threads with intervals of 50 and 20 mm in five different arrangements. For naming in data sheets, a syntax is provided that begins with VESA , followed by MIS for Mounting Interface Standard , the applicable part of the standard and the applicable options of this part. The following specifications with regard to the screen diagonal and the maximum total mass are assigned to the individual parts:
- Part A: Open, Future Developments;
- Part B: 10.2 to 20.2 cm screen diagonal; Max. 2 kg; 4 screws 4 mm, 0.7 pitch, 6 mm length
- Part C: 20.3 to 30.4 cm screen diagonal; Max. 4.5 kg; 4 screws 4 mm, 0.7 pitch, 8 mm length
- Part D: 30.5 to 58.3 cm screen diagonal; Max. 14 kg; 4 screws 4 mm, 0.7 pitch, 10 mm length
- Part E: 58.4 to 78.6 cm screen diagonal; Max. 22.7 kg; 6 screws 4 mm, 0.7 pitch, 10 mm length
- Part F: 78.7 to 228.6 cm screen diagonal; Max. 113.6 kg; n Screws 6 mm, 1.0 pitch, 10 mm length or 8 mm, 1.25 pitch, 16 mm length
In practice, parts A – C are not widely used and part D is used instead for smaller monitors down to 12 ".
From 200x200mm, M6 screws are used instead of M4 screws, for even larger brackets either M8 screws (Samsung, up to 15mm length), or hole patterns with 6, 8, ... threads according to the standard VESA MIS-F.
Examples:
- VESA MIS-D 75: 4x M4 threads in a square arrangement 75 × 75 mm in the center of the back of the screen.
- VESA MIS-D 100 C: Part D of the standard, 4x M4 threads in a square arrangement 100 × 100 mm in the center of the back of the screen.
- VESA MIS-D 100 L / R: Part D of the standard, 4x M4 threads in a rectangular arrangement 100 × 50 mm on the left and right edge of the back of the screen.
- VESA MIS-E 200 C: Part E of the standard, 4x M4 threads in a rectangular arrangement 100 × 200 mm in the center of the back of the screen.
- VESA MIS-E 200 D: Part F of the standard, 4x M6 threads in a rectangular arrangement 200 × 200 mm in the center of the back of the screen.
See also
Individual evidence
- ↑ Number of members on VESA.org. Retrieved February 2, 2016.
- ↑ Wi-Fi Alliance and VESA Announce Collaboration to Advance 60 GHz Technology ( Memento of the original from February 3, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , Press release, September 9, 2013, accessed February 3, 2016
- ↑ Program for calculating the video timings according to GTF
- ↑ Program for calculating the video timings according to CVT and GFT
- ↑ VESA Flat Display Mounting Interface (FDMI) Overview (PDF; 65 kB) VESA. Retrieved April 14, 2011.
- ↑ a b c VESA Flat Display Mounting Interface Standard (PDF; 2.06 MB) VESA. January 16, 2006. Retrieved April 14, 2011.
- ↑ Meaning of the VESA standard in TV mounting . In: plasma holder . ( plasma-halter.de [accessed on February 22, 2018]).
- ↑ How To Determine The Screw Size For VESA Wall Mounts. Retrieved February 22, 2018 .
