El sensor táctil acústico de onda masiva es una capa de cubierta de vidrio en la superficie de la pantalla. Los transductores X e Y están soldados en las esquinas adyacentes del vidrio y conectados al controlador con un par de cables blindados. Cada par de cables está conectado respectivamente a la línea de señal ya la línea de tierra. Un escudo triangular protege los transductores X e Y y los cables conectados. Una matriz de franjas de reflexión con un ángulo de 45 grados está grabada a lo largo de ambos lados del vidrio como una guía de ondas. Los reflectores están opuestos entre sí. Los bordes están pulidos para garantizar un eco acústico correcto.
The touch sensor can be laminated on any thickness of glass to increase durability, riot resistance and safety. It can also be laminated directly on CRT or flat panel displays. Use silicone gel as the lamination medium.
Acoustic bulk wave touch screen technology is based on transmitting high-frequency sound waves through the touch sensor covering the surface of the display. The detection work is to continuously monitor the touch sensor to determine whether there is a touch. It includes the following processes
(1) Transmit sound waves and wait for reflected wave response.
(2) Digital reflected wave response.
(3) Analyze the signal and determine the touch activity.
(4) Send the verification result to the host.
transmit and receive sound waves
X and Y transducers alternately emit sound waves (in transmission mode). The transducer is installed in the upper left corner of the sensor and converts electrical pulses into sound waves. The transducer emits multi{{0}}cycle ultrasonic waves into the sensor glass at a velocity of 0.135 inches/microsecond.
The sound wave propagates along the reflection fringe, is reflected by the reflection fringe to the opposite light edge, and then reflected back to the fringe array, and then converted to the transducer (in receiving mode). The first reflector sends a signal back, then the second, the third, and so on. Then decompose the anti-lr signal to separate the noise from the effective information.
Digital reflection signal
X or Y transducer receives the reflected signal, amplifies and demodulates the signal and converts it into a digital signal. Adjust the amplitude if necessary.
Analyze digital signals
Fingers or other media that can absorb sound waves touch the sensor, which absorbs the energy of the sound waves and reduces the amplitude of the waves. This energy attenuation appears on the signal as a drop in amplitude. The touch is detected by comparing the current digitized data with the previous detection or reference data. The different results of the current and previous data are processed through the digital filter to determine whether there is a touch and a touch position on the sensor (brother: K is the coordinate, Z is the pressure axis).
Send the test result to the host
The controller transmits the coordinates to the main processor, and the main processor processes the data for use by the application program.
