摘要:
An infrared detecting device. The device includes a drive power supply circuit which supplies a drive current to each of signal circuits comprised of an I/V conversion circuit, a voltage amplification circuit, a detection circuit and an output circuit. The drive power supply circuit is comprised of a current generating circuit and a distribution circuit. The current generating circuit includes a reference current source, a fixed current source which provides a fixed current based on reference current and a variable current source which provides a variable current stepped up or down to any of different currents based on the reference current. The distribution circuit distributes the drive current to a part of the signal circuits based on the current from the fixed current source and distributes the drive current to a remaining part of the signal circuits based on the current from the variable current source. The device reduces current consumption while keeping the performance or behavior of the circuits in stable state.
摘要:
An infrared detecting device for reducing current consumption while maintaining performance is disclosed. The device includes a drive power supply circuit which comprises a current generating circuit and a distribution circuit, and which supplies a drive current to each of signal circuits comprising an I/V conversion circuit, a voltage amplification circuit, a detection circuit and an output circuit. The current generating circuit includes a reference current source, a fixed current source providing a fixed current based on the reference current and a variable current source providing a variable current stepped up or down to any different currents based on the reference current. The distribution circuit distributes the drive current to a part of the signal circuits based on the current from the fixed current source and distributes the drive current to a remaining part of the signal circuits based on the current from the variable current source.
摘要:
In an infrared-rays detector, a pyroelectric element detects existence or movement of a human body, and the output signal of the pyroelectric element is converted to a voltage signal. Then, the voltage signal is subjected to waveform analysis. Then, a detection signal is outputted only when a waveform generated by a human body is detected by the waveform analysis. For example, the voltage signal is amplified at two different frequency ranges, and the amplified signals are used for discriminating a signal due to a human body. Then, a noise such as a popcorn noise of the pyroelectric element is prevented to be detected erroneously as generated by a human body.
摘要:
The object detection device includes: a pyroelectric element configured to output a current signal in response to a change in an amount of infrared light; an I/V conversion circuit including an operational amplifier, a capacitive element serving as a feedback circuit, and a discharging circuit, and configured to convert the current signal to a voltage signal; an A/D conversion circuit configured to convert the voltage signal to a first digital signal; a digital filter configured to extract a detection component having a frequency included in a frequency band associated with an object from a waveform represented by the first digital signal by subjecting the first digital signal to an arithmetic processing, and create a second digital signal representing a waveform of the detection component; a judgment circuit configured to detect the target based on the second digital signal; and a control unit configured to control the discharging circuit based on a period corresponding to a predetermined frequency not greater than a lower limit of the frequency band to discharge electric charges stored in the capacitive element.
摘要:
A current-voltage converting circuit (2) is provided with a first feedback circuit (5) and a correcting transistor (Q1). The first feedback circuit (5) outputs, of an output voltage (V10), a voltage according to a magnitude of a low-frequency component that is not greater than or equal to a predefined first cut-off frequency. The correcting transistor (Q1) extracts a correction current (I21) according to a magnitude of an output of the first feedback circuit (5) from a sensor current (I10). The first feedback circuit (5) has a first integrating circuit (9) and a sample-and-hold circuit (10). The first integrating circuit (9) integrates the output voltage (V10) of a conversion section (3). The sample-and-hold circuit (10) samples and holds an output of the first integrating circuit (9) during a sensing period at which a pulsed detection signal is inputted. Means for preventing an incidence of ambient light onto a light-receiving section can be simplified or omitted as a result.
摘要:
The object detection device includes: a pyroelectric element configured to output a current signal in response to a change in an amount of infrared light; an I/V conversion circuit including an operational amplifier, a capacitive element serving as a feedback circuit, and a discharging circuit, and configured to convert the current signal to a voltage signal; an A/D conversion circuit configured to convert the voltage signal to a first digital signal; a digital filter configured to extract a detection component having a frequency included in a frequency band associated with an object from a waveform represented by the first digital signal by subjecting the first digital signal to an arithmetic processing, and create a second digital signal representing a waveform of the detection component; a judgment circuit configured to detect the target based on the second digital signal; and a control unit configured to control the discharging circuit based on a period corresponding to a predetermined frequency not greater than a lower limit of the frequency band to discharge electric charges stored in the capacitive element.
摘要:
A wireless sensor device including a sensor configured to sense a target object and provide a sensor signal of varying levels indicative of condition of the target object, a signal processing circuit configured to amplify the sensor signal and provide an amplified electric analog signal, and a detection circuit configured to receive the amplified analog signal and provide a detection output when the electric analog signal goes beyond a predetermined detection threshold. A radio transmitter transmits a radio detection signal in response to the detection output. A power supply is configured to provide an electric power to the signal processing circuit and the radio transmitter and includes a power generating element which converts an external energy into the electric power to be accumulated in the power supply. A controller activates the radio transmitter only in response to the detection output, permitting the radio transmitter to generate the radio detection signal.
摘要:
A wireless sensor device of low energy consumption operates over a prolonged period of time for providing a reliable sensor result. The wireless sensor device includes a sensor configured to sense a target object and provide a sensor signal of varying levels indicative of condition of the target object, a signal processing circuit configured to amplify the sensor signal and give an amplified electric analog signal, and a detection circuit configured to receive the amplified analog signal and provide a detection output when the electric analog signal goes beyond a predetermined detection threshold. Also included in the device is a radio transmitter which transmits a radio detection signal in response to the detection output. Further, the device includes a power supply configured to provide an electric power to the signal processing circuit and the radio transmitter; and a power generating element which converts an external energy into the electric power to be accumulated in the power supply. The controller is included to activate the radio transmitter only in response to the detection output, permitting the radio transmitter to generate the radio detection signal. Thus, the radio transmitter can be kept inactivated until receiving the detection output, thereby saving energy to prolong the operating life of the device.
摘要:
A pyroelectric infrared ray sensor is constituted with a current-voltage converting circuit utilizing an impedance of feedback capacity, obtained by adding the feedback capacity to an operational amplifier receiving as an input an element current from a pyroelectric element, whereby the current-voltage converting circuit can be improved in S/N ratio without altering characteristics of the pyroelectric element.
摘要:
A pyroelectric infrared ray sensor includes a voltage amplifying circuit provided with a signal amplifying part having a non-inverting amplifier, with an integrating circuit, and with voltage dividing resistors connected at a position where an input V.sub.IN to the voltage amplifying circuit and an output V.sub.B of the integrating circuit are resistance-divided to a non-inverting input terminal of the signal amplifying part which is practically formed by an operating amplifier, wherein the signal amplifying part includes a low-pass filter formed by a resistor and a capacitor, whereby the electrostatic capacity of the required capacitor can be minimized, and the entire circuit can be minimized in size and also in manufacturing costs.