Abstract: An IR-cut filter includes a substrate and an infrared filtering film. The substrate is made of sapphire, and includes a first surface and a second surface opposite to the first surface. The infrared filtering film covers the first surface of the substrate and increases the reflectivity in relation to infrared light, thus filtering out the infrared light. The infrared filtering film includes a number of first high refraction index layers and a number of first low refraction index layers alternately stacked on the first surface of the substrate.

Abstract: A camera module includes an image sensor, a lens assembly mounted on the image sensor, and a shell defining a receiving space. The image sensor and the lens assembly are accommodated in the receiving space. The lens assembly is fixedly engaged in the shell.

Abstract: A noise elimination circuit of a audio output device includes a sound card for receiving a digital audio signal and transforming it to an analog audio signal; an audio reproduction apparatus such as a audio output device connected to the sound card for receiving the analog audio signal; a power supply connected to the sound card for providing a working voltage thereto; a capacitor connected between the power supply and ground; and a discharging circuit also connected between the power supply and ground, for discharging deposited current in the capacitor when the audio output device is cut off. The discharging circuit is controlled according to the state of the power supply.

Abstract: A communication circuit of a serial peripheral interface (SPI) device includes a master device and a plurality of slave devices. One of the slave devices includes a plurality of general purpose input/output (GPIO) pins. The chip select terminal of the master device is connected to the control terminal of the slave device having the GPIO pins. The GPIO pins respectively are connected to the control terminals of other slave devices. The slave device having the GPIO pins receives an instruction having an address signal from the master device and compares the addresses are identical, the slave device having the GPIO pins communicates with the master device. Otherwise the slave device transmits the address signal to the control terminals of the other slave devices through the GPIO pins. The other slave devices compare the address signal with their own address. The slave device having the identical address communicates with the master device.

Abstract: A printed antenna disposed on a substrate, includes a radiation part, a feed line, and at least one first ground part. The radiation part is for radiating and receiving electromagnetic signals, and includes a hollow portion and a pair of openings. The hollow portion is defined in the radiation part, and comprises a first slot connected to a second slot, which is connected to a third slot, wherein the second slot extends between the first slot and the third slot forming a substantially h-shaped pattern. The openings are formed at two edges of the radiation part. The feed line for feeding the electromagnetic signals to the radiation part is electrically connected to the radiation part. The at least one first ground part for grounding is disposed at one side of the feed line.