It's a plane interface with a little arc on one side! If you look closely, you will know that it says HDMI, which is a high-definition video interface and can be connected to a high-definition display or projector. There is also a function key fn+... on the notebook to switch the monitor or projector, but this interface is generally useless. Unless you want an external projector or monitor. This interface is for this purpose.

There are other interfaces: (These interfaces may be similar to USB interfaces)

IEEE 1394: Commonly known as "Firewire" interface, it is similar to USB interface, but the transmission speed is much faster than USB, and the interface size is much smaller. It is mainly used for video cameras (DV) or external drives.

SD？ MS/Pro？ MMC？ XD: multifunctional card reader socket, supporting mainstream SD card and other types of memory cards.

Expansion port 3: It can be connected to a desktop monitor, and it is also very powerful.

ESATA: Seldom use various SATA types of external devices, such as SATA hard disks.

HDMI interface:

HDMI (high definition multimedia interface) is a digital video/audio interface technology and a special digital interface suitable for image transmission. It can transmit audio and audio-visual signals at the same time, and the highest data transmission speed is 5Gbps. At the same time, there is no need for line number/analog or analog-to-digital conversion before signal transmission. HDMI can be combined with Broadband Digital Content Protection (HDCP) to prevent copyrighted audio-visual content from being copied without authorization. The extra space provided by HDMI can be used for future upgraded audio and video formats. And because a 1080p video and an 8-channel audio signal need less than 4Gbps, there is still a lot of room for HDMI. This makes it possible to connect DVD player, receiver and PRR with one cable respectively.

20 10 On March 4th, MILLICENSING, LLC released the HDMI specification version 1.4a on behalf of the original development members of HDMI. Its functions include key enhancements of 3D applications, mandatory 3D format of broadcast content and 3D format named "Shangxia".

Because the expression of "HDMI 1.4" is too broad to show the specific supporting technology of the equipment, it is completely forbidden to use the version number identification method of "HDMI 1.4" in this specification. According to the new version of Trademark and Logo Usage Specification, when selling and promoting HDMI 1.4 standard cables, HDMI cable manufacturers are prohibited from using version number logo, all labels, descriptions and packaging. Old cables marked with version numbers should be removed within one year.

For other HDMI devices except cables, all version numbers should be removed before 20 12 1. Prior to this, the manufacturer should apply the version number identification on the premise of clearly indicating the technology used, such as "HDMI V. 1.4 with audio return channel and HDMI Ethernet channel" (HDMI V. 1.4 supports ARC audio return channel and HEC Ethernet channel), but it is forbidden to use the universal "HDMI v. 1.4 compatibility".

Me. HDMI output compatibility test

1. Compatible with HDMI interface TV: simultaneously transmit audio and video;

2. Compatible with DVI interface TV: only transmit video;

3. Power amplifier compatible with HDMI interface: only transmit audio;

Judging criteria: The audio that HDMI interface can transmit supports "any compressed digital audio that can be output through S/PDIF" and "uncompressed digital audio with 2/6/8 channels and sampling rate of 32- 192KHZ", and can output "I2S (digital transmission interface with time difference better than S/PDIF and suitable for short-distance communication) and SPDIF audio". It can always get the audio quality of CD; The video that can be transmitted by HDMI interface supports "HD 1080I", "HD 720P", "normal interlaced" and "normal progressive", and also supports NTSC and PAL TV systems. The video format of YUV or RGB coding can be automatically output according to the acceptable video state of the receiving end;

2. Reliability test of. HDMI port plugging and unplugging

Reliability of hot plug of 1. interface: when the disk drive and the receiver are working, plug in and plug out the HDMI interface, whether the devices at both ends work normally, and whether the audio and video functions output by HDMI are normal;

2.ESD test

3. Interface plugging and unplugging life test: Plug and unplug the HDMI interface for many times to test the service life of the HDMI interface; Criteria: The receiver can output HDMI audio and video signals normally when it is hot-plugged, and the source system should still work normally; The service life of the interface plug-in needs at least 5000 times;

Three. Reliability test of. HDMI output

1. Drive capability test of source and output;

2. Test the attenuation characteristics of connecting wires;

3. Reliability of high-frequency and large-capacity data transmission;

Judgment standard: the longest transmission can be 30 meters, ensuring normal sound and image; Fluency of large-capacity DVD (multi-subtitle, multi-channel) discs;

4. Whether the 4.HDMI output is normal at startup and standby.

Four. Test standard. HDMI cable and interface

Please refer to the test standard of HDMI interface and cable supplier;