Abstract: A keyboard key device includes a keycap and a substrate unit. The substrate unit includes a light-emitting component, a light guide plate, and a light transmission plate. The light guide plate has first and second end surfaces, and at least one light-condensing hole. The first end surface is formed with an uneven microstructure for diffuse reflection of light rays. The light transmission plate has first and second side surfaces, and an outer reflective layer coated on the second side surface. A portion of light rays emitted from the light-emitting component and into the light transmission plate pass through the outer reflective layer, and the remainder of the light rays are reflected by the outer reflective layer.

Abstract: A keyboard key device includes a keycap and a substrate unit. The substrate unit includes a light-emitting component, a light guide plate, and a light transmission plate. The light guide plate has first and second end surfaces, and at least one light-condensing hole. The first end surface is formed with an uneven microstructure for diffuse reflection of light rays. The light transmission plate has first and second side surfaces, and an outer reflective layer coated on the second side surface. A portion of light rays emitted from the light-emitting component and into the light transmission plate pass through the outer reflective layer, and the remainder of the light rays are reflected by the outer reflective layer.

Abstract: A backlight module adapted for use in an input device includes a circuit board, a light guide plate, a plurality of light-emitting elements, and a reflective structure. The light guide plate disposed on the circuit board is formed with a microstructure. The reflective structure includes a reflective plate disposed on the light guide plate opposite to the circuit board, and a first reflective layer disposed on the reflective plate opposite to the light guide plate. The first reflective layer is configured to allow a portion of a light emitted from the light-emitting elements to pass therethrough, and to allow a portion of the light to be reflected back to the light guide plate and then be diffuse reflected by the microstructure formed on the light guide plate.

Abstract: A power factor control circuit has a power factor controller that determines if the power factor control circuit is operated at a continuous current mode (CCM) or a discrete current mode (DCM), and outputs PWM signals corresponding to the present current mode. A duty cycle of the PWM signals is equal to a sum of a feed-forward control parameter and a current compensation parameter. The current compensation parameter contains a difference value between a reference current and an inductor current in the power factor control circuit. Accordingly, a switching power supply circuit can acquire the PWM signals corresponding to the present current mode to effectively resolve the issue of harmonic distortion.

Abstract: A power factor correction circuit and a control method thereof uses a power factor controller to generate a compensation current signal according to an input voltage of an AC-DC conversion circuit and a filter capacitor value. An estimation current signal is generated by summing up the compensation current signal and an inductor current signal of the AC-DC conversion circuit. And then, a pulse width modulation signal is outputted to the AC-DC conversion circuit according to the estimation current signal. The filter capacitor value is chosen from a capacitor value of a capacitor connected to the AC power source, an input capacitor value of the AC-DC conversion circuit, or sum of both the capacitor values. Therefore the estimation current signal approaches an input current signal of the power factor correction circuit to increase the power factor at the input terminals of the power factor correction circuit and decrease a harmonic distortion.

Abstract: A power factor control circuit has a power factor controller that determines if the power factor control circuit is operated at a continuous current mode (CCM) or a discrete current mode (DCM), and outputs PWM signals corresponding to the present current mode. A duty cycle of the PWM signals is equal to a sum of a feed-forward control parameter and a current compensation parameter. The current compensation parameter contains a difference value between a reference current and an inductor current in the power factor control circuit. Accordingly, a switching power supply circuit can acquire the PWM signals corresponding to the present current mode to effectively resolve the issue of harmonic distortion.

Abstract: A projective capacitive touch apparatus and a method for identifying multi-touched positions are provided. The multi-touched positions are touched on a projective capacitive touch panel. The method comprises the following steps: generating a first set of reference values according to the first touch position; generating a plurality of second sets of reference values according to a second touch position, and filtering out at least one ghost second set of reference values from the second sets of reference values. Furthermore, the plurality of second sets of reference values comprise a real second set of reference value and at least one ghost second set of reference values, while the ghost second set of reference values comprises parts of the first set of reference values.

Abstract: An exemplary method for detecting touch position includes the steps of: detecting a plurality of sensing points, obtaining at least one first signal and a plurality of second signals on the sensing points, wherein the at least one first signal each has an energy above a preset threshold, the second signals each has an energy below the preset threshold, positions of the sensing points where the second signals being detected are successive with a position(s) of the sensing point(s) where the at least one first signal being detected; performing a weighted averaging operation applied to the energies of the at least one first signal and the second signals and taking a result of the weighted averaging operation as a first dimension coordinate of a touching point, wherein weights of the respective energies are associated with the positions of the sensing points where the at least one first signal and the second signals being detected.

Abstract: A control method for a touch screen device is provided. The control method comprises the steps of: enabling an active mode of a touch panel; defining at least one active area on the touch panel; inputting a touch input into any one position on the touch panel; determining whether the touch input exists in the active area; and saving calculation of coordinate values of the position corresponding to the touch input and outputting a corresponding predetermined output signal in accordance with the touch input when the touch input exists in the active area.

Abstract: A projective capacitive touch apparatus and a method for identifying multi-touched positions are provided. The multi-touched positions are touched on a projective capacitive touch panel. The method comprises the following steps: generating a first set of reference values according to the first touch position; generating a plurality of second sets of reference values according to a second touch position, and filtering out at least one ghost second set of reference values from the second sets of reference values. Furthermore, the plurality of second sets of reference values comprise a real second set of reference value and at least one ghost second set of reference values, while the ghost second set of reference values comprises parts of the first set of reference values.