Abstract: A reading device for capacitive sensing element comprises a differential capacitive sensing element, a modulator, a charge-voltage conversion circuit, a phase adjustment circuit, a demodulator and a low-pass filter. The modulator outputs a modulation signal to the common node of the capacitive sensing element and modulates the output signal of the capacitive sensing element. The two input terminals of the charge-to-voltage conversion circuit are connected to two non-common nodes of the capacitive sensing element. The charge-to-voltage converter read the output charge of the capacitive sensing element and convert it into a voltage signal. The modulator generates a demodulation signal through the phase adjustment circuit. The demodulator receives the demodulation signal from the phase adjustment circuit and demodulates the output of the charge-to-voltage conversion circuit. The low-pass filter is connected to the output of the demodulator for filtering the demodulated voltage signal to output the read signal.

Abstract: A light guide board includes an incidence surface, an emitting surface, and a reflection surface. The incidence surface is frosted and has a roughness-enhanced zone corresponding in location to a light source. The emitting surface forms micro-structures on portions adjacent to the incidence surface and two opposite end surfaces. The portions of the emitting surface forming the micro-structures have magnitude increased roughness as compared to portions that are not provided with micro-structures so that light transmitting through the micro-structures is subject to further diffusion. The reflection surface forms a plurality of prisms extending from the incidence surface with a small (shallow) depth to an opposite surface with a large (deep) depth, with the height of the prisms increasing with the length thereof so that the prism surface of the prisms changes from minimum to maximum, which ensures uniformity of the light emitted from the light guide board.

Abstract: A renewable wear-proof elbow is disclosed which can be connected to a pipe and become a part thereof for transporting particles of powdered material via compressed air. The renewable wear-proof elbow comprises a main elbow portion and a buffer chamber. The main elbow portion comprises: (a) an inlet at one end of the main elbow portion having a first flange for connection with a first section of the pipe; (b) an outlet at another end of the main elbow portion having a second flange for connection with a second section of the pipe; (c) a first side opening formed on a side wall of the main elbow portion opposite the inlet; and (d) a third flange formed around the first side opening. The buffer chamber has a second side opening, a central axis, and a fourth flange, which is formed around the second opening and is engageable with the third flange so as to allow the buffer chamber to be removably affixed to the main elbow portion at the first side opening thereof.