Abstract: A heart pulse detector includes a light emitting diode for emitting a short pulse light toward body tissue and a photo sensor for receiving light signal modulated by blood pulse flow through body tissue. The output current of photo sensor is charging a capacitor during pulse light and is discharging the same capacitor during no pulse light for same period of pulse light. The ambient light signal is then cancelled out from the detected light signal. The light current signal is transferred to a voltage signal after sample and hold procession. Finally heart pulse signal is detected out from the voltage signal without the interference of ambient light.

Abstract: The present invention offers a liquid crystal display system integrated with touch detection circuit. The electrodes used in the display function can be also used as the touch sensors of the touch detection function. Time multiplexing technology is used in the present invention. No additional fabrication process is required in the present invention as compare with that of liquid crystal display panel without touch detection function. No additional fabrication process means there is no additional absorption and reflection of light.

Abstract: The present invention offers an object proximity detector and object position detector. The variation of frequency of an oscillator is used to detect the proximity of an object to a sensor plate. The dependence of the sensitivity of the detector on the area of the sensor plate is reduced by conducting the sensor plate to two capacitors in series. The conducting wire of the sensor plate can be flexible without causing error detection. In the sensor element of the sensor oscillator, a resistor is connected at one terminal of the sensor plate to form a high pass filter. A resistor and a capacitor are added to the sensor oscillator to form a low pass filter. The high pass filter is used to reduce the low frequency electromagnetic interference. The low pass filter is used to reduce the high frequency electromagnetic interference.

Abstract: The present invention offers an object proximity detector and object position detector. The variation of frequency of an oscillator is used to detect the proximity of an object to a sensor plate. The dependence of the sensitivity of the detector on the area of the sensor plate is reduced by conducting the sensor plate to two capacitors in series. The conducting wire of the sensor plate can be flexible without causing error detection. In the sensor element of the sensor oscillator, a resistor is connected at one terminal of the sensor plate to form a high pass filter. A resistor and a capacitor are added to the sensor oscillator to form a low pass filter. The high pass filter is used to reduce the low frequency electromagnetic interference. The low pass filter is used to reduce the high frequency electromagnetic interference.

Abstract: The present invention offers a heart pulse detector. Two pairs of contact electrodes mounted on each handrail of treadmill separately. A electrocardiography heart pulse detector built in the control panel of the treadmill has input terminal which electrically connected to the contact electrodes. A front end circuit within the heart pulse detector receives the electrical cardio signals of a user from the input terminal and preprocesses the electrical cardio signals for later processing by the reminder functional blocks of the heart pulse detector. A hand touching detection circuit assembly in the heart pulse detector is also connected to the input terminal. The hand touching detection circuit sense the signals from the input terminal and send out hand on/off data for using to control the speed of the treadmill and to control the operation of the heart pulse detection.

Abstract: The present invention offers an alarm clock with a proximity detector consists of an alarm clock, an object proximity detector and sound generator. The alarm clock can be an analog clock or a digital clock with LCD display. When the time of clock meets the setting time, alarm signal will come from the sound generator, it is not necessary to touch a push button switch of the alarm clock to control the alarm signal, only the proximity of human body or a finger can stop the alarm signal of an alarm clock. The sensor of the object proximity detector can be a capacitive proximity sensor or a magnetic proximity sensor. Most of the technology use capacitive sensor because of low power consumption and low cost.

Abstract: The present invention discloses an automatic page detector, to determine which page of a book is open. The automatic page detector uses a sensor plate and an inductor as a sensor. In the invention, there is a sensor plate at each page of the book and the locations of the sensor plates for different pages are different. There is an array of inductors just beneath the sensor plates when the book is closed. The inductors are connected to the feedback loop of a LC oscillator through analog switches. The proximity of a sensor plate to an inductor will change the frequency of the LC oscillator. Scanning the analog switches by a microprocessor and detecting the variation of frequency of the LC oscillator during each scanning time period, the status of each sensor plate will be detected and we can determine which page of a book is opened.

Abstract: The present invention discloses an automatic page detector, to determine which page of a book is open. The automatic page detector uses a sensor plate and an inductor as a sensor. In the invention, there is a sensor plate at each page of the book and the locations of the sensor plates for different pages are different. There is an array of inductors just beneath the sensor plates when the book is closed. The inductors are connected to the feedback loop of a LC oscillator through analog switches. The proximity of a sensor plate to an inductor will change the frequency of the LC oscillator. Scanning the analog switches by a microprocessor and detecting the variation of frequency of the LC oscillator during each scanning time period, the status of each sensor plate will be detected and we can determine which page of a book is opened.

Abstract: The present invention discloses an automatic page detector, to determine which page of a book is open. The automatic page detector uses a magnet and an inductor as a sensor. In the invention, there is a magnet at each page of the book and the locations of the magnets for different pages are different. There is an array of inductors just beneath the magnets when the book is closed. The inductors are connected to the feedback loop of a LC oscillator through analog switches. The proximity of a magnet to an inductor will change the frequency of the LC oscillator. Scanning the analog switches by a microprocessor and detecting the variation of frequency of the LC oscillator during each scanning time period, the status of each magnet will be detected and we can determine which page of a book is opened.

Abstract: The present invention discloses an automatic page detector, to determine which page of a book is open. The automatic page detector uses a magnet and an inductor as a sensor. In the invention, there is a magnet at each page of the book and the locations of the magnets for different pages are different. There is an array of inductors just beneath the magnets when the book is closed. The inductors are connected to the feedback loop of a LC oscillator through analog switches. The proximity of a magnet to an inductor will change the frequency of the LC oscillator. Scanning the analog switches by a microprocessor and detecting the variation of frequency of the LC oscillator during each scanning time period, the status of each magnet will be detected and we can determine which page of a book is opened.

Abstract: The present invention offers an object proximity detector and an object position detector. The variation of frequency of an oscillator is used to detect the proximity of an object to the sensor plates. The dependence of frequency on process parameter is minimized by a compensation capacitor. It is not need to calibrate the product during the manufacture. In order to magnify the sensitivity, the sensor plates are placed in the feedback loop of the oscillator, instead of at the input of the oscillator. The independence of the process parameter and increasing of the sensitivity can be achieved by adding the compensation capacitor and place the sensor plates in the feedback loop at the same time. Multiple transmission gates are connected to the input and the output of the oscillator, and the sensor plates are connected to the transmission gates to form an object position detector.

Abstract: The present invention disclosed a position detection device and method for use in a plane surface to determine the position of a capacitive coupling device. Two arrays of row and column conductive wires form two layers on a substrate, said two layers are isolated by an insulated layer; between each two row wires there is a common row wire; between each two column wires there is a common column wire. Said common row and common column wires are connected to a common row terminal and common column terminal respectively. AC signal is applied to two adjacent wires sequentially to determine point P is between row k and row k+1. Then AC signal is applied to row k only, and then applied to row k+1 only, to determine point P is near row k or row k+1. Finally, apply AC signal to common rows and then to all rows to determine point P is closed to row wire or common wire. Then repeats the above process for the columns. By combining the above processes the position in a two-dimensional space is determined.

Abstract: The present invention disclosed a position detection device and method for use in a plane surface to determine the position of a capacitive coupling device. Two arrays of row and column conductive wires form two layers on a substrate, said two layers are isolated by an insulated layer; between each two row wires there is a common row wire; between each two column wires there is a common column wire. Said common row and common column wires are connected to a common row terminal and common column terminal respectively. AC signal is applied to two adjacent wires sequentially to determine point P is between row k and row k+1. Then AC signal is applied to row k only, and then applied to row k+1 only, to determine point P is near row k or row k+1. Finally, apply AC signal to common rows and then to all rows to determine point P is closed to row wire or common wire. Then repeats the above process for the columns. By combining the above processes the position in a two-dimensional space is determined.

Abstract: Circuitry for an electronic tone generator effectively isolates a tone modulating RC network from the electroacoustic output device and associated volume control systems. This isolation prevents low or variable impedance of the output portion of the generator from adversely affecting the charge and discharge rate of the RC network. Isolation circuitry includes a MOSFET connected in a source follower circuit to convert the voltage signal from the RC network to a comparable current signal which is amplified through a pair of MOSFETs in a current mirror circuit.

Abstract: A shaped waveform tone generator circuit is contained entirely in an integrated circuit and has a pair of push-pull amplifiers for driving a piezo-buzzer. The output from an RC network controls current flow in a first follower transistor connected to one voltage source and in a second follower transistor connected to a second voltage source. A pair of CMOS switches alternately connect the inputs of the amplifiers to the first and second transistors. A tone signal controls operation of the two CMOS switches.

Abstract: An analog current source polarity switching circuit composed of a pair of main P-channel and N-channel polarity switching transistors is supplemented by a dummy load switching circuit for connecting each current source transistor in the polarity switching circuit to a dummy load when the main polarity switching transistor is turned off and for disconnecting the dummy load when the main polarity switchng transistor is turned on. The dummy load switching circuit preferably employs a second pair of complementary P-channel and N-channel transistors controlled through an inverter from the input to the main polarity switching transistor circuit. MOSFET transistors are employed throughout the circuit.