Abstract: Some disclosed implementations include an ultrasonic sensor stack and an acoustic resonator. The acoustic resonator may be configured to enhance ultrasonic waves transmitted by the ultrasonic sensor stack in an ultrasonic frequency range that is suitable for ultrasonic fingerprint sensors. In some examples, the acoustic resonator may include one or more low-impedance layers residing between a first higher-impedance layer and a second higher-impedance layer. Each of the one or more low-impedance layers may have a lower acoustic impedance than an acoustic impedance of the first higher-impedance layer or an acoustic impedance of the second higher-impedance layer. At least one low-impedance layer may have a thickness corresponding to a multiple of a half wavelength at a peak frequency of the acoustic resonator. The peak frequency may be within a frequency range from 1 MHz. to 20 MHz.

Abstract: A display device having a substrate; a first thin film transistor (TFT) on the substrate, the first TFT having a first active layer, a first gate insulator, and a first gate electrode; a second TFT on the substrate, the second TFT having a second active layer, a second gate insulator and a second gate electrode. The first gate insulator is disposed between the first gate electrode and the first active layer, and the first gate insulator is in contact with the first active layer. The second gate insulator is disposed between the second gate electrode and the second active layer, and the second gate insulator is in contact with the second active layer. The first active layer is a different material than the second active layer, and a hydrogen concentration of the second gate insulator is less than a hydrogen concentration of the first gate insulator.

Abstract: An engine starter for a radio control model includes an output shaft concentrically connected to and synchronously rotated with a T-shaped drive axle of the engine to start the engine. A drive wheel is sleeved on the output shaft for receiving an extra power. A limit wheel is sleeved on the output and synchronously rotated with the output shaft. The limit wheel is selectively driven by the drive wheel. A gear box is secured on the engine and provided to receive the output shaft, the drive wheel and the limit wheel. A torsion adjust device is mounted to a free end of the output shaft after the output shaft extending through the gear box. The drive wheel is idle running when the torsion force from the engine is greater than that from the torsion adjust device for protecting the engine from a forced operation.

Abstract: The present invention provides a way to measure the position of an instrument that is mounted on an instrument shaft within a clutched mounting system, the instrument shaft being driven through a reduction gearbox by a motor shaft. The position of the instrument is measured as a function of the position of the motor shaft and the position of the instrument shaft, the measurement of the position of the motor shaft providing greater precision than the position of the instrument shaft. Because the mounting system is clutched, it is necessary to check at intervals whether the measurement of the motor shaft position no longer accurately represents the position of the instrument, in which case the measurement of the motor shaft position is resynchronized to the measurement of the instrument shaft.

Abstract: A wrench for an engine clutch of a radio control model includes a handle having a receiving space longitudinally defined in the handle. A control unit is rotatably mounted in the receiving space, and includes a first end formed with a press portion and a second end formed with a hook. The press portion presses a centrifugal lever of the engine clutch when mounting and the hook engages to the centrifugal lever when detaching. A drive unit is pivotally mounted to one end of the handle and corresponds to the press portion. The drive unit includes a hole defined in a free end thereof for receiving an input shaft of the engine clutch. A partition is securely laterally attached to the drive unit and has a separation extending therefrom. The separation is provided for easily detaching/mounting a torsion spring of the engine clutch.

Abstract: A manual engine starter includes a starting device having a driven shaft selectively connected to a crank of the engine and a drive shaft connected to the driven shaft for driving the driven shaft and starting the engine. The drive shaft has a tubular drive portion formed with a guide side and the driven shaft having a driven portion that is rotatably received in the tubular drive portion and engaged to the guide side and moved along the guide so as to make the driven shaft moved along an axis thereof when the drive shaft is rotated to drive the driven shaft. A puller laterally is mounted the starting device for driving the drive shaft to drive the driven shaft.