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With the development of the display, it has more and more interfaces. In this case, many people are more and more confused about what the interfaces of the display are used for. Even some friends who often pay attention to IT are the same. Some JS or manufacturers have seen this, and often mislead consumers through exaggeration or false propaganda in publicity and shopping guides, making them confused and deceived.
To this end, it is necessary to conduct a comprehensive analysis of the interface used by the current display. At present, there are many interfaces involved in the display, among which VGA, DVI, HDMI, USB, DP and so on are mainly used. Some of these interfaces are also divided into different types and versions. In this picture analysis, it will be introduced and analyzed in detail one by one.
VGA interface:
The VGA interface is a common interface that we have been using since the CRT era to the present. It is a color-difference analog transmission interface, a D-type port with 15 holes on it, which transmit different signals respectively. In addition, the VGA interface is also called the D-Sub interface.
characteristic:
1. In theory, it can support 2048x1536 resolution screen transmission.
2. Because VGA is an analog signal transmission, it is easy to be interfered, and signal conversion is easy to bring about signal loss.
3. At 1080P resolution, users can clearly feel the loss of the picture with the naked eye.
4. It is recommended to use the following monitors with a resolution of 1080P.
VGA is the most widely used display interface at present. Almost most of the low-end monitors have a VGA interface. However, due to its obvious shortcomings, the high resolution cannot achieve the desired refresh rate and only the image input has no sound input. It's hard to make it work in mid-to-high-end monitors.
DVI interface:
DVI (Digital Visual Interface[1]), that is, digital video interface. It was launched in 1999 by Silicon Image, Intel (Intel), Compaq (Compaq), IBM, HP (HP), NEC, Fujitsu (Fujitsu) and other companies to form DDWG (Digital Display Working Group, Digital Display Working Group) launched. interface standard. There are three types of DVI interfaces: DVI-A, DVI-D and DVI-I. DVI-D and DVI-I are divided into single-channel and dual-channel.
DVI-A, analog interface, used to switch to VGA, has been abandoned.
DVI-A, digital interface, is divided into single channel (18+1) and dual channel (24+1). It is not convertible to VGA, nor is it possible to use an adapter.
DVI-I, compatible with analog and digital interfaces, can actually be said to be the integration of A and D, which can be transferred to VGA, but requires an adapter.
characteristic:
1. It can only transmit images and supports limited resolution.
2. It only supports 8bit RGB signal transmission, which is not perfect for some wider color gamut displays
.
Compatibility with devices is relatively general, especially flat-panel TVs.
DVI transmits digital signals, and the digital image information will be directly transmitted to the display device without any conversion, thus reducing the tedious conversion process of digital →analog →digital and greatly saving time, so its speed It is faster, effectively eliminates the smear phenomenon, and uses DVI for data transmission, the signal is not attenuated, the color is purer and more realistic, and it is also widely used at present.
HDMI interface:
I often see netizens mention in evaluation articles, why does this monitor not have an HDMI interface? It seems that the lack of HDMI interface is a major disadvantage of the monitor now. Why is the HDMI interface so popular? It can be said that HDMI is the most common interface in our daily life, and it is widely used in home multimedia equipment.
In April 2002, Hitachi, Panasonic, Philips, Silicon Image, Sony, Thomson, and Toshiba jointly established the HDMI High-Definition Multimedia Interface Organization, and began to develop a new digital video/audio interface technology that meets the standards of the high-definition era. After more than half a year of preparation, the HDMI organization officially released the HDMI 1.0 standard on December 9, 2002, marking the official entry of HDMI technology into the historical stage.
High Definition Multimedia Interface (English: High Definition Multimedia Interface, HDMI) is a digital video/audio interface technology. It is a dedicated digital interface suitable for image transmission. It can transmit audio and video signals at the same time. GB/s
characteristic:
1. The latest HDMI1.4 standard, capable of supporting 4Kx2K resolution transmission, with Ethernet channel, audio return channel, support for 3D functions, etc.
2. It supports the output of 4K resolution, which improves the foundation for the support of current 4KK TVs and monitors.
3. Support 3D function, which can meet the display signal transmission requirements of 3D TV.
4. It can also support more than 30-bit color gamut space, and can display the most vivid and vivid colors under various standards.
Display interface analysis
HDMI is a digital interface that provides the best video quality since all analog connections (such as component video or S-video) require no loss when converting from analog to digital. This difference is especially noticeable at higher resolutions, such as 1080p. Digital video will be sharper than component video, eliminating the softness and smearing found in component video. Tiny, high-contrast details such as text bring this difference to the extreme. In addition, there are many reasons why the HDMI interface is widely used, which also extends HDMI interfaces of various sizes, mainly including Micro, mini HDMI and standard HDMI interfaces.
DisplayPort (DP for short):
The DP interface is the successor of DVI. Now the most common ones are the DisplayPort interface and the miniDP interface developed by Apple. Compared with DVI, the DP interface has improved a lot, and there have been qualitative changes in bandwidth and customizability.
In May 2006, the Video Electronics Standards Association (VESA) confirmed the 1.0 version of the standard, and upgraded to 1.1 after half a year, providing support for HDCP, and 2.0 is also planned to be launched this year. A competitor to HDMI and UDI and a potential successor to DVI, DisplayPort has the backing of industry giants like AMD, Intel, NVIDIA, Dell, HP, Lenovo, Philips, Samsung, and more, and it's free to use.
1. The longest external distance of the DP interface can reach 15M, the rate can reach 10.8Gb/S, and it can support 2560x1600 resolution and 30/36bit color depth.
2. It also allows audio and video signals to be transmitted in a common cable, and supports a variety of high-quality digital audio.
3. In addition to the 4 main transmission channels, it also provides a powerful auxiliary channel with a bandwidth of 1Mbps and a maximum delay of only 500us, which can achieve a variety of functions.
4. The Apple miniDP interface is more powerful, not only the interface is small, but also can support the compatibility of various interfaces, just need to add an adapter.
At present, the latest 1.3 standard of the DP interface, the speed can reach 21.6Gb/s, and the resolution can directly support up to 4K. It is mainly used in PCs, which is why the current 4K monitors all use the DP interface.
DP and HDMI interface comparison:
HDMI Advantages: There are many products that support HDMI, and it is more mainstream at present.
Disadvantages: Poor compatibility with PCs, unable to support 3 or 6-screen multi-screen output
DP advantage: PC support is perfect, support 3 to 6 screen output
Disadvantage: come out late, non-mainstream
In short, DP is theoretically stronger and more advanced, but it came out late, and the application area is narrow, and it is biased towards the PC field.
USB and Audio Interface:
Now, more and more monitors are also equipped with USB interface, and it is still the latest USB3.0 interface. For most monitors, configuring USB only enables the monitor to have USB HUb function. The user can easily connect to the computer through the downstream USB interface of the monitor.
However, for some smart displays, the USB configuration is naturally the same as the USB interface on the computer host.
Some monitors are directly equipped with an upstream interface, which is purely for the purpose of the built-in speakers of the display, while some have two upstream and downstream ports. In addition to the built-in speakers, they can also output, such as HDMI input and audio output.
Summarize:
A monitor may have display output interfaces including HDMI, DVI, VGA, DP, etc., as well as additional interfaces such as USB, audio, and USB-HUB. Through the above introduction, I hope you can have a general understanding of the interface of the monitor. Advantages and disadvantages, uses, etc.