Touch screen is widely used in life in a variety of places, such as some fairs, shopping centres, cinemas and other places can see the touch one machine, contact can be found, most of them are multi-touch, which is the principle of how?
First, what is multi-touch technology
Many small-sized touch screen only supports single-point touch, can only identify and support each time a finger touch, click, if at the same time there are more than two points are touched, you can not make the correct response. And multi-touch technology can break down the task into two aspects of the work, one is the simultaneous acquisition of multi-point signals, the second is to judge the significance of each signal, which is also known as gesture recognition, so as to achieve screen recognition of the five fingers at the same time to do the clicking, touching action.
Second, the principle of multi-touch technology
Multi-touch technology is the core of the suppressed total reflection technology. By the LED light beam from the touch screen cross-section to the surface of the screen, will produce reflection. If the screen surface layer is air, when the angle of incident light to meet certain conditions, the light will be completely reflected on the screen surface. However, if a substance with a high refractive index (e.g. a finger) is pressed against the acrylic panel, the condition of total reflection on the screen surface will be broken, and part of the light beam will pass through the surface and be projected onto the finger surface. The uneven surface of the finger leads to beam scattering (diffuse reflection), scattered light through the touch screen to reach the photoelectric sensor, the photoelectric sensor will be converted into electrical signals, the system thus obtain the corresponding touch information.
Third, the characteristics of multi-touch
1, multi-touch is in the same display interface on the multi-point or multi-user interaction mode, abandoning the keyboard, mouse single-point operation.
2, the user can be single-point touch with both hands, but also with a single click, double-click, pan, press, scroll and rotate and other different gestures to touch the screen, to achieve arbitrary control, so as to better and more comprehensive understanding of the relevant characteristics of the object (text, video, pictures, satellite films, three-dimensional simulation and other information).
3, according to customer demand, customised touch screen, touch software and multimedia systems; can be used in conjunction with professional graphics software.
Fourth, common touch gestures:
Gesture touch refers to the use of fingers or hands on the touch screen for specific actions to achieve a variety of operations and functions. It provides users with an intuitive and natural way of interaction. Here are some common touch screen gestures for touch:
(Tap): A quick, light press of a finger on a touchscreen. A tap can be used to select, activate or open an element or application.
(Double Tap): Tapping the touchscreen twice in rapid succession. Double taps are often used to zoom in or out of content or images.
(Long Press): Press and hold an area or element of the touchscreen for an extended period of time. Long presses can be used to bring up context menus, copy and paste, and more.
(Swipe): Rapidly slide your finger across the touchscreen. Swiping can be used to scroll up and down the page, switch screens, view images, etc.
(Slide to Unlock): Slide your finger a specific path to unlock the device.
(Pinch): Use two fingers to move inward and closer to each other at the same time. Pinch can be used to shrink images, web pages, or map content.
(Spread): Use two fingers to move outward and apart at the same time. Spreading can be used to zoom in on an image, web page or map content.
(Scroll): Use your finger to make a continuous swipe across the touchscreen. Scroll can be used to view large amounts of content, lists, or pages as they scroll.
(Rotate): Performs a rotating motion with two fingers on the touchscreen. Rotate can be used to rotate pictures, maps, or for gesture recognition.
(Two-Finger Drag): Use two fingers to drag an object on the screen. Two-Finger Drag can be used to move files, pictures, etc.