Talking about the interactive flat panel, what’s your impression? 4K screen high resolution?multi-points touch and writing, etc? or Eco-friendly digital whiteboard function? Or wireless screen Mira-cast mobile phones, tablets, and laptops to smart panels? or the function of scanning the QR code to download memos? Yes, these are all functions of interactive panels. But do you know how these functions are realized? What technologies are applied to the smart interactive screen? How does it realize interaction? Why the mobiles and tablet screens can be projected to the interactive panel without cable and projector? In this article ,we will analyze them one by one, including interactive touch technology, backlight technology, wireless screen share technology, and type C data transfer technology.

What’s interactive touch technology?

The interactive panels are divided into Infrared touch, capacitive touch, and optical touch tech for large size 55″ 65″ 75″ 86″ interactive screens.

Infrared touch technology

it is also called IR touch, the interactive touch screen is covered with IR rays from every bezel of the screen, including the top bar bezel, bottom bar bezel, and sides bezels of the screen. See picture 1-infrared touch screen structure.

• There are infrared LEDs on the PCB bars that emit infrared lights to cover every dot of the screen. in this way, all screens of any angel are covered. An X-axis and Y-axis dual-dimensional infrared light can precisely lock the touch point, When people touch the screen, lighting on the horizontal and vertical axes locks onto a unique point, improving touch accuracy and sensitivity. 

What’s the advantage of an infrared touch screen?

• Infrared touch screen characters include high precision, fast and no delay touch, mature and stable tech, and are widely used. 
  • High precision: since there is an emitter in the top bar and a receiver in the bottom bar, also the same in the left bezel and right bezel, so every point of touch can be exactly recorded no matter in the center of the screen or very side corner. There are no touch dead spots on the entire large screen. 
  • No-delay touch: There is no delay when touching the surface of the screen, the sensitivity is high and adjustable. Touch sensitivity will affect the writing and touch experience when using interactive flat panels. The high sensitivity of IR touch frame makes the infrared touch screen more popular in the international IFP market. 
  • Mature and stable, widely used tech: Compared with optical touch and capacitive touch, IR touch technology is the most mature tech and widely used in large-size display touch screens. And the top leading interactive smart board brands mostly use the IR touch tech for the panels. 

Capacitive touch screens

• Capacitive touch screens control displays that utilize the electrical properties of the human body as input. When a finger (or specialized input device, such as a stylus) comes in contact with the display it detects when and where on the display the user touches it. The biggest advantage of a capacitive touchscreen display is that no writing distance. When the user touches or writes on the touch panel screen, it feels no gap on the screen surface.
• Many customers feel a 1-2mm distance when writing on an infrared touch screen, but there is no distance on a capacitive touch screen, why? Because the capacitive touch screen is mounted to LCD or LED backlights tightly. The X-axis and Y-axis sensor electrode is flat and covered all of the screens, that’s why there is no writing gap.

But the disadvantage of the capacitive touch screen is also very obvious-high cost. The capacitive touch screen is most widely used in small screens like mobile and tablet touch screens, but for education interactive display screens, 55″ 65″ 75″ 86″ 98″ are very large size, so the total cost is pretty high. And the industry application is not so common as IR touch, which makes the cost keep in a high standard and can not cut down. Take 75″ interactive flat panel as a sample, the same configuration screen with capacitive touch cost is about 10-20% higher than IR touch screen. so the capacitive interactive touch panels are more popular in the European and USA markets.

• Optical touchscreen technology uses multiple optical sensors to detect the touch point, which registers the touch just before physical contact with the screen. The features of the optical touch screen are not precise, and it is not easy to adjust the precision. 
•  And 65inch 75inch 85inch and 86inch optical touch panels are more widely used in China market, while very few choose optical touch for foreign markets. 
• The structure of optical touch is as follows: 

• Since optical touch sensors are located in the top corners when touching the screen, there may be some touch dead space, that is to say, some areas or spots are not so sensitive and exact when using optical touch tech. The sensitivity of optical touch tech determines that the application is limited. 

Zero bonding technology

The latest technology used on the interactive panels to improve the writing experience and smoothness on touch screens. The key point is that zero bonding technology reduces the distance between the touch glass and the backlight panel, and the refractive index is reduced when the distance is small, thereby improving the visual effect and reducing the visual error. To conclude is that, zero bonding technology improves users’ writing and viewing feelings. We will introduce it detailed in another article.

LCD, LED display tech

From the pixel control way of the interactive display screen, the screen display technology is divided into LCD, LED, and CRT display tech. 

• LCD stands for Liquid Crystal Display, which is a type of flat panel display using liquid crystals in its primary form of operation. How do LCDs work? A display is made up of millions of pixels. The quantity of a display screen commonly refers to the number of pixels, for example, a 4K screen is made up of 3840*2160 pixels. With all the pixels on a display working together, the display makes millions of different colors. 
• LED: A LED display is a flat panel display that uses an array of light-emitting diodes as pixels for a video display. Their brightness allows them to be used outdoors
• CRT stands for Cathode Ray Tube. 
• LCD is a big leap because it replaced gas plasma, LED and CRT, etc. 
• LCDs allowed displays to be much thinner than cathode ray tube (CRT) technology.
•  LCDs consume much less power than LED and gas-display displays because they work on the principle of blocking light rather than emitting it. Where an LED emits light, the liquid crystals in an LCD produce an image using a backlight.
• some people also call LCD interactive panels LED panels because interactive flat panels also use LED diodes as backlights, Which own a great advantages like low power consumption, small size, long life time and stable output, and good quality .

Wireless screen mirroring- 5G communication projection

Screen sharing: Generally, there are multiple screens in the home network or local area networks, such as touch all-in-one interactive panels or smart TV, laptop (computer) screen, mobile phone screen, and tablet screen. Displaying content from one screen to another is called screen sharing. For example: display the computer screen on the TV screen, display the mobile phone screen on the TV screen, etc.

Wireless screen sharing(or called miracast)

Compared with wired screen transmission, wireless screen miracast is to use of WIFI to display the screen of a mobile phone, tablet, or computer on the interactive touch panel or TV. The wireless screen-sharing technology breaks the constraints of wires connection and realizes that there is no need for wiring, no external adapter, and no need to connect to Wi-Fi. After pairing with DS interactive screens, it can automatically form a network to realize point-to-point encrypted transmission, which is reliable and stable and meets the security requirements of the intranet. And it can transmit pictures, audio, video, and file also. The development and application of this technology solve the problem that in traditional conference scenarios, a lot of cables need to be connected to the computer screen, and the signal of the mobile phone and tablet computer cannot be projected to the large screen display. Wireless screens miracast improve great convenience in corporation conferences and education classroom teaching.

There are currently three mainstream technologies for wireless screen sharing or projection: AirPlay, DLNA, and Miracast. (These three screen projection technologies will be analyzed separately in another article, and only a brief introduction will be given here.)

AirPlay Screen Mirroring

AirPlay Screen Mirroring is a wireless technology developed by Apple in the United States. It can wirelessly transmit pictures, audio, and video on iOS devices such as iPhones, and iPad to any device that supports AirPlay. All DS interactive screens support Airplay.

DLNA wireless screen sharing

DLNA, the full name of Digital Living Network Alliance, is a set of interconnection agreements between computers, mobile devices, and consumer appliances initiated by Sony, Intel, and Microsoft.

Unlike AirPlay, DLNA can only transmit media data (ie: music, photos, videos, link information), cannot transmit other types of files, and cannot achieve mirroring (screen sharing). The mobile phone or computer is only responsible for pushing and not playing, and it is directly played and displayed by the TV.

Miracast (WiFi-Display) wireless screen sharing

Miracast (WiFi-Display): Miracast is a wireless display standard protocol established by the Wi-Fi Alliance in 2012 based on Wi-Fi Direct. As long as devices that support this protocol can share video images wirelessly, for example, mobile phones can directly play videos or photos on TV or other devices through Miracast.

How is the wireless screen share on the interactive flat panel realized?

(In this article, we mainly analyze the hardware projection of the wireless screen projector.)

• The technology to realize wireless screen sharing or projection is 5G WIFI communication technology. A 5G signal receiver is built in the interactive flat panel motherboard. And the wireless screen dongle for screen sharing is equipped with a 5G signal transmitter module. After the user paired the wireless screen dongle with DS interactive flat panels, by WIFI direct connection tech, the dongle can mirror the laptop’s video, audio, and pictures to the interactive screen.
• Max 7meters screen sharing – Wireless screen sharing tech currently supports a max 7 meters screencast. That means, if the wireless screen dongle is far away from the interactive screen’s receiver, it will be hard for the 5G modules to communicate, then it will cause the screen sharing to delay or fail.
• Multi-device to mira-cast at the same time. Wireless screen miracast supports multiple devices to transmit images and signals to the large IFPD screen at the same time. Unlike other screen projection technologies, Miracast wireless screen transmission under WIFI direct connection can support many-to-one transmission. For example, the teacher may transmit the picture to the student’s device during class, or transmit the picture of the teacher or a specific student to the electronic whiteboard, which can bring many interesting experiences to digital life.

USB Type C fast data transfer and power supply tech.

USB-C (on DS smart board, it is marked as a Type-C port) is a 24-pin USB connector system with a rotationally symmetrical connector. The designation C refers only to the connector’s physical configuration or form factor and should not be confused with the connector’s specific capabilities, which are designated by its transfer specification (such as USB 3.2). Refer to WIKIPEIDA

• USB-C cables interconnect hosts and devices, replacing various other electrical cables and connectors, including USB-A and USB-B, HDMI, DisplayPort, and 3.5mm audio jacks.

Fast data transfer

• The full-featured USB Type C cables can transfer files at high speed and transmit video, audio, and power simultaneously. When you connect your mobile device to a USB-C computer, you can transfer data such as photo, video, and audio files at up to 10 Gbps, While the theoretical transfer speed of USB 3.0 is 4.8 Gbit/s (600MBps) vs. 480 Mbit/s (60MBps)

Quick Charging

• A standard USB-C connector can provide 2.5 watts of power, which is the same as most USB-A connectors. But many devices use something called a Power Delivery (PD) protocol, which will let a USB-C cable deliver up to 100 watts. PD cables can charge laptops and other high-wattage devices, something impossible for the older USB standards.