Abstract: Disclosed is a method of taking electric power from a low voltage bypass for providing low voltage power supply for an integrated circuit. Also provided is an alternating current (AC) directly driven LED integrated circuit adapted to use the method; the integrated circuit includes a voltage stabilizing circuit, a low voltage electronic switch circuit, an under-voltage control circuit, and a comparative amplification circuit, and has three pins, a positive power supply terminal, a zero potential reference terminal, and a common terminal for current sampling and for the low voltage electronic switch. The method of taking electric power from a low voltage bypass for providing low voltage power supply for an AC directly driven LED integrated circuit, and the integrated circuit adapted to use the method have the advantages of low power consumption and cost, high efficiency and reliability, and fewer pins and external devices, and are easy to use.

Abstract: The prior integrated circuits (ICs) for AC direct driving LEDs all adopt a method of taking power direct from an AC high voltage to supply power to the ICs, but such ICs have the disadvantages of large power consumption, poor reliability and high cost, etc. The present invention provides a method of taking power with low-voltage bypass for supplying low-voltage power to an IC. The present invention also provides an IC for AC direct driving LEDs, which is applicable to the method of taking power with low-voltage bypass. The IC comprises a voltage stabilizing circuit, a low-voltage electronic switching circuit, an under-voltage control circuit and a comparing and amplifying circuit, and is provided with three pins, i.e., a positive power-supplied terminal, a zero potential reference terminal and a common terminal for current sampling and low-voltage electronic switching.

Abstract: A computer input device includes a light source assembly forming an incident light beam that strikes an area on a surface beneath the input device with large incident angle. A light sensing assembly in the input device is positioned to receive scattered light and includes a band-pass filter. A barrier is located directly above the area where the light beam is incident on the top surface to prevent light from traveling directly from the light source assembly to the light sensing assembly.

Abstract: An input device encodes motion using a laser self-mixing velocimeter. The laser beam is directed at a disk or other moving member. As light from that beam is reflected back into the emitting cavity of the laser, the beam power output fluctuates because of the self-mixing effect and generates a beat signal. The beat signal frequency is used to determine the speed of the member's motion. The direction of motion is also determined based on the beat signal. A difference frequency analog phase locked loop filters the beat signal. A zero-point control disables motion detection when the average beat signal amplitude falls below a threshold. A triangle modulator generates a triangle wave for the laser bias current, with the triangle wave frequency being a submultiple of the beat signal frequency.

Abstract: An input device includes an optical waveguide, one or more light sources, one or more imaging sensors, and a translator. The optical waveguide has an input surface, a back surface substantially opposite the input surface, and a side surface therebetween. The input surface has a plurality of different input locations. The one or more light sources are positioned to introduce light into the optical waveguide. A distortion of each different input location of the input surface causes a portion of light within the optical waveguide to exit from the optical waveguide at a different escape location of the side surface. The one or more imaging sensors are positioned and aimed to detect an escape location of a portion of light exiting from the side surface. The translator determines an input location corresponding to the escape location for each detected escape location.

Abstract: Optical tracking systems, method, and devices are described in which optical components detect light within a substantially planar region adjacent to a user device. Tracking logic may receive signals output by the optical components and determine coordinates associated with a movement of a pointing object through the substantially planar region. The tracking logic may then provide for translation of the coordinates into an action on a display, such as, for example, a movement of a cursor or other icon on the display.

Abstract: A computer input device includes a light source assembly forming an incident light beam that strikes an area on a surface beneath the input device with large incident angle. A light sensing assembly in the input device is positioned to receive scattered light and includes a band-pass filter. A barrier is located directly above the area where the light beam is incident on the top surface to prevent light from traveling directly from the light source assembly to the light sensing assembly.

Abstract: A laser range finder includes a laser and a photosensitive element. The laser projects a beam onto a target surface. A backscattered portion of the laser beam returns to the laser from the target surface and enters the laser emitting cavity. Variations in laser output power are detected by the photosensitive element, which provides a “beat” signal to a frequency detection circuit. The frequency detection circuit includes a difference frequency analog phase locked loop (DFAPLL) providing a purified form of the beat signal. The frequency of the purified beat signal is determined and used to calculate distance to the target surface.

Abstract: Optical tracking systems, method, and devices are described in which optical components detect light within a substantially planar region adjacent to a user device. Tracking logic may receive signals output by the optical components and determine coordinates associated with a movement of a pointing object through the substantially planar region. The tracking logic may then provide for translation of the coordinates into an action on a display, such as, for example, a movement of a cursor or other icon on the display.

Abstract: A laser range finder includes a laser and a photosensitive element. The laser projects a beam onto a target surface. A backscattered portion of the laser beam returns to the laser from the target surface and enters the laser emitting cavity. Variations in laser output power are detected by the photosensitive element, which provides a “beat” signal to a frequency detection circuit. The frequency detection circuit includes a difference frequency analog phase locked loop (DFAPLL) providing a purified form of the beat signal. The frequency of the purified beat signal is determined and used to calculate distance to the target surface.