C-Media Electronics Inc. Patent applications |
Patent application number | Title | Published |
20150092951 | HEADPHONE WITH ACTIVE NOISE CANCELLING AND AUTO-CALIBRATION METHOD THEREOF - A headphone with active noise cancelling and auto-calibration method thereof is disclosed. The headphone includes a first gain-amplifier, an active noise cancelling module, a speaker, a measurement circuit, a calibration control circuit and USB driving circuit. Auto-calibration of the headphone is by means of a USB interface in the instant disclosure, so as to significantly reduce calibration time and then improve production efficiency. | 04-02-2015 |
20140341264 | AUTO-DETERMINING SAMPLING FREQUENCY METHOD AND DEVICE THEREOF - The present disclosure provides an auto-determining sampling frequency method. The method is for determining sampling frequency for an input signal of a single wire transmission interface. Each frame of the input signal includes a preamble and binary data presented in a plurality of bits. The method includes utilizing an internal sampling clock to acquire a plurality of period widths of the preamble and the binary data in the input signal and determining range of the sampling frequency according to the detected period widths of the preamble and the binary data. | 11-20-2014 |
20140142734 | VIRTUAL SIGNAL SOURCE GENERATING APPARATUS AND METHOD THEREOF - A virtual signal source generating apparatus is provided. The virtual signal source generating apparatus includes at least an audio interface, a control module, a detecting module and a processing module. The control module is used for acquiring an audio signal from a signal source, wherein the audio signal includes a clock information and an audio information. The detecting module is used for detecting whether the audio interface is coupled to the signal source. The processing module is used for transmitting the audio signal. If the detecting module detects that the signal source disappears when the virtual signal source generating apparatus is in the recording mode, the control module transmits a control signal to the processing module so that the processing module transmits a virtual audio signal to a host. | 05-22-2014 |
20140139284 | COMMON MODE NOISE CANCELLATION CIRCUIT FOR UNBALANCED SIGNALS - This invention provides a common mode noise cancellation circuit for the unbalanced signals. The unbalanced signals come from a signal source with a first signal terminal and a second signal terminal having a first grounding potential. The common mode noise cancellation circuit comprises a grounding terminal and a subtractor. The grounding terminal with a second grounding potential is electrically coupled to the second signal terminal of the signal source through an impedance unit. The subtractor comprises a first receiving terminal, a second receiving terminal and a signal output terminal. The first receiving terminal and the second receiving terminal are electrically coupled to the first signal terminal and the second signal terminal respectively for receiving the unbalanced signals. The subtractor subtracts the noise coming from the first receiving terminal and the noise coming from the second receiving terminal to reduce the output noise of the signal output terminal. | 05-22-2014 |
20130170369 | CLOCK RATE CONTROLLER AND METHOD THEREOF AND ELECTRONIC DEVICE THEREOF - An exemplary embodiment of the present disclosure illustrates a clock rate control method. Firstly, a usage of a first input first output (FIFO) buffer in an electronic device is detected. Then, whether the usage falls within a first specific interval is determined, wherein the first specific interval has a first upper limit value and a first lower limit value. When the usage is larger than the first upper limit value, a clock rate of the inner device of the electronic device is increased; when the usage is less than the first lower limit value, the clock rate is decreased. | 07-04-2013 |
20120229115 | VOLTAGE AMPLITUDE LIMITING CIRCUIT OF FULL DIFFERENTIAL CIRCUIT - A voltage amplitude limiting circuit of a full differential circuit is provided for limiting voltage levels of a differential signal. The voltage amplitude limiting circuit includes a reference voltage generating unit and a replacing circuit. The reference voltage generating unit generates a high reference voltage and a low reference voltage. The replacing circuit is coupled to the reference voltage generating unit, a first input terminal and a second input terminal. When voltage at the first input terminal is greater than the high reference voltage, the replacing circuit uses the high reference voltage to replace the voltage at the first input terminal to serve as an output. When voltage at the first input terminal is less than the low reference voltage, the replacing circuit uses the low reference voltage to replace the voltage at the first input terminal to serve as an output. | 09-13-2012 |
20120045074 | SYSTEM, METHOD AND APPARATUS WITH ENVIRONMENTAL NOISE CANCELLATION - Disclosed herein are system, method and apparatus with environmental noise cancellation. The instant disclosure is particularly adapted to a receiver module having at least two inputs. The two inputs respectively receive a main audio portion and the audio with majority of environmental noise. The system firstly calibrates the audio signals to reduce the error caused by the difference between the two inputs. An adaptive beamforming technology and a speech extractor are respectively used to extract the environmental noise portion with less main audio and the main audio portion with less noise. After a process of time-to-frequency domain transformation, a non-linear noise suppression technology is introduced into estimating the environmental noise and acquiring a gain. After noise suppression processed with the gain, a sequence of audio signals is output after a frequency-to-time domain transformation. | 02-23-2012 |
20110159855 | METHOD FOR PROVIDING BACKGROUND SOUND TO COMMUNICATION DEVICE AND SYSTEM APPLYING THE METHOD - Disclosed is a method for providing background sound to a communication device and a system applying the method. The method is preferably applied to a voice communication procedure. In the meantime, a background sound is simultaneously played with a telephone call according to a user's selection or a sound schedule. In accordance with an embodiment, the steps in the method firstly include a step of receiving a call, and a step of activating a noise-suppression function and a background-sound enabling procedure. The background-sound enabling procedure is conducted to play the background sound at the time of the call based on the user's selection, or a sound schedule. In particular, the user can decide to play or not to play the background sound while phoning in the beginning. At last, the method ends the voice communication procedure with or without the background sound after hanging up the phone. | 06-30-2011 |
20110121879 | METHOD OF AUTOMATIC GAIN MODULATION AND APPARATUS IMPLEMENTING THE SAME - Provided is method for automatic audio gain modulation and a related apparatus. In order to prevent the unstable signals as continuously increasing or decreasing the gain when the signals hover around an upper threshold, it's featured that the method is to predict the signal intensity as pre-adding a predict gain in a hold time before outputting signals. By determining whether the prediction exceeds a predetermined threshold or not, the suitable and adjustable gains can be obtained without exceeding the predetermined threshold. In the automatic gain control mechanism, it's to decrease the gain gradually as automatically entering an attack time, or to increase the gain gradually as performing a conventional auto-gain control procedure including entering a release time. The claimed method can modulate the gain automatically by predicting the gain, and confine the signals under a threshold. In addition to avoid sawtooth phenomena, the method can stabilize the signals. | 05-26-2011 |
20110014980 | AUDIO SIGNAL TRANSMISSION APPARATUS AVOIDING NOISE GENERATION AND METHOD THEREOF - An audio signal transmission apparatus avoiding noise generation is applied to a game platform functions by executing a recording process, and comprises: an analog-to-digital converter, an intermediary processing unit, a counter, and a controlling unit. The analog-to-digital converter is used for converting an analog audio signal to a first digital audio signal. The intermediary processing unit is connected with the analog-to-digital converter for transmitting the first digital audio signal. The counter controls the intermediary processing unit to output the first digital audio signal after counting a specific time. The controlling unit, connected with the counter and the intermediary processing unit, is used for transmitting the first digital audio signal to the game platform. Therefore, the present invention can achieve the purpose for avoiding noise generation when the audio signal transmission apparatus plugs into the game platform. | 01-20-2011 |
20110014978 | Game Apparatus - A video and audio signal processor includes a game engine interface mechanism, a video mechanism, a video card, an integration mechanism and a sound effect card. The game engine interface mechanism provides graphic parameters and original sound effect parameters. The video mechanism receives the graphic parameters from the game engine interface and provides video data based on the graphic parameters. The video card receives the video data from the video mechanism and instructs a display to provide images based on the video data. The integration mechanism receives the graphic parameters and the original sound effect parameters from the game engine interface mechanism, analyzes the graphic parameters to derive desired sound effect parameters and integrates the desired sound effect parameters with the original sound effect parameters. The sound effect card instructs at least one speaker to provide sounds under the control of the integration mechanism. | 01-20-2011 |