Pioneer Electronic Corporation

Pioneer Corporation

Tadashi Kosuga

Yoshiharu Ueki

Hisashi Suganuma

Reisuke Sato

Tomohisa Yokogawa

Masanao Okatani

Tadashi Ogawa

Yoshiaki Ishibashi

Haruo Kama

Hiroshi Onishi

Koichi Kasa

Kazuhiko Mogi

Shinobu Kawarada

Yoshimi Tsuboi

Kazuhiko Takahashi

An electronic apparatus includes a specific circuit component having a circuit constant included in a function circuit serving a specific circuit function, and a measurement terminal for measuring the circuit constant. The circuit constant has a value in accordance with a specification. The electronic apparatus can avoid a misidentification during an identification procedure of the specification.

Electronic apparatus, specification identification method therefor and manufacturing method therefor

An input trap circuit removes a predetermined frequency component included in an input signal and then outputs the input signal to a circuit at a later stage. The input trap circuit is provided with: a parallel oscillation circuit in which a pair of variable capacitance diodes are connected in series such that cathodes thereof are connected to each other at a junction portion and in which an inductance is connected in parallel to the variable capacitance diodes between anodes of the variable capacitance diodes at both ends thereof; a voltage applying device for applying a voltage to the junction portion so as to vary capacitance values of the variable capacitance diodes on the basis of reverse voltage characteristics of the variable capacitance diodes respectively; and a variable capacitor element connected between the junction portion and a ground.

Tunable input trap circuit and image trap circuit

A receiving circuit includes: an antenna for receiving signal waves of two different frequency hands; a first receiving circuit for receiving a first receiving signal having a frequency; a second receiving circuit for receiving a second receiving signal having another frequency; a switch element for switching a signal path from the antenna to either one of the first receiving circuit and the second receiving circuit; a first diode; a second diode; and reverse bias voltage applying elements, each connected in parallel with one of the first diode and the second diode. The switch element is connected to a direct current power supply, and the switch element controls the connection of the direct current power supply such that the first diode and the second diode are biased in the forward direction when the first receiving signal is received and the first diode and the second diode are biased in the reverse direction when the second receiving signal is received.

Receiving circuit

An electrostatic destruction preventing circuit for a receiving apparatus, is provided with: a first Zener diode coupled to a receiving terminal of the receiving apparatus; a second Zener diode coupled to a ground terminal of the receiving apparatus, and connected to the first Zener diode in series and in reverse polarities to each other; a first resistor connected in parallel to the first Zener diode; and a second resistor connected in parallel to the second Zener diode.

Electrostatic destruction preventing circuit and receiving apparatus

A radio receiver with two receiving systems includes a CPU for selecting the appropriate ranges of local signal generators in the two receiving systems so that local signals generated by the local signal generators do not fall into the frequency range of a received RF signal.

Radio receiver with two receiving systems

A diversity receiver has distributors each of which is connected with each of a plurality of antennas, and as many antenna switches as there are receivers. Each of the antenna switches has as many contacts as there are distributors. The distributor distributes a radio frequency signal from the antenna into as many signal paths as there are receivers. Each of the antenna switches is connected with each of the distributors via the contact connected with the signal path. A demodulated signal selecting circuit has as many contacts as there are said receivers. The demodulated signal selecting circuit receives the demodulated output of the receivers via each of said second contacts to selectively output the demodulated outputs of the receivers.

Diversity receiver

An RF tank circuit includes a coil with a center tap, the RF tank circuit being for receving an input RF signal, and for providing a balanced mixer circuit by being arranged in one of: a) receiving a local signal through second and third capacitors at first and second coil ends, respectively, with the center tap grounded; and, b) receiving a local signal at the center tap. An impedance is connected between the first and second coil ends of the RF tank circuit, the impedance providing low impendance for a predetermined intermediate frequency signal, and high impedance for a predetermined high frequency signal and a local signal. A bias resistor is connected between a middle connecting point of the impedance and ground. The coil of the RF tank cicuit can be one of a primary and second winding of an isolation transformer, with a remaining one of the primary and secondary windings being connected to an RF signal source, the isolation transformer being for preventing a leakage of a local signal to the RF signal source.

Center-tapped coil-based tank circuit for a balanced mixer circuit

A first PIN diode is connected to the input side of a tuner at the front end of an FM receiver, in an AC coupled fashion parallel to the tuner. A correction inductance is connected parallel to the first PIN diode in an AC coupled fashion. The tuner is connected, at its output side, parallel to a series-connected circuit of a correction capacitor and a second PIN didode. The anodes of the first and second PIN diodes are supplied with an automatic gain control (AGC) voltage. When the AGC voltage varies, the resistances of the first and second PIN diodes vary in a manner to adjust the degree to which the correction inductance and the correction capacitor affect the resonance in the tuner.

Signal attenuator

A manual tuning pulse generator for use in an electronic tuning control device of a radio receiver having a tuning circuit, which control device utilizes an up/down counter, is disclosed which comprises a first manual means for selectively producing an up count signal and a down count signal to be supplied to the up/down counter, a second manual means ganged with said first manual means for producing a variable control signal and means responsive to the variable control signal to produce a clock pulse signal having a variable frequency, the pulses of the clock pulse signal being adapted to be counted up or down by the up/down counter the content of which is utilized to shift the tuning frequency.

Manual tuning pulse generator

The present invention is a magnetic tape running state and tape run amount display device which displays visually the running direction and speed or the run amount and direction of the magnetic tape. An up-down counter is provided with a clock input signal having a pulse generated in correspondence with the run of the tape and is also provided with a count control signal. The count control signal has an UP signal generated when the tape is being transported in a first or forward direction, and has a DOWN signal generated when the tape is being transported in a second or reverse direction. The up-down counter provides a binary output count signal to a display circuit in correspondence with the clock input signal and the count control signal. The up-down counter can also be provided with a reset input responsive to a reset signal which acts to reset the count back to logic 0. The display circuit provides a visual representation of the binary output signal, and may include a first binary-to-digital decoder and a second binary-to-digital decoder, each being responsive to a preselected portion of the binary bits provided by the up-down counter. A plurality of light emitting diodes are connected between decimal output lines of the first and second binary-to-digital decoders for providing a visual indication of the tape running state and run amount. In one arrangement, the diodes are arranged to define a line. The display circuit also can be responsive to the binary tuning signal provided by an electronic tuning type receiver.

Magnetic tape running state and tape run amount display device

The present invention is an electronic tuning type receiver having a band display unit and a numerical frequency display unit. The numerical frequency display unit provides a visual numerical display of the frequency selected by the receiver. The band display unit provides a visual indication of the relationship of the selected frequency with respect to the frequency band being tuned by the receiver.

Electronic tuning type receiver having a band display and numerical

A combination device having a magnetic recording and reproducing unit and an electronic tuning type receiver, where the channel presetting switches of the electronic tuning type receiver also can act as the operating switches of the magnetic recording and reproducing unit. The electronic tuning type receiver is of the type which is tuned by control signals provided to a tuning means by a plurality of channel selecting switches. A selection circuit is interposed between the tuning means and the plurality of channel selecting switches and provides the plurality of control signals to the tuning means when a selection switch is in a first binary state, and provides the plurality of control signals to a tape-control section when the selection switch is in a second binary state. The tape-control section, in response to the plurality of control signals, controls the mode of operation of the magnetic recording and reproducing unit, and also provides a signal indicating the mode of operation to a sensing circuit. The sensing circuit, in turn, provides mode signals to a digital display unit which can visually display the mode of operation when the magnetic recording and reproducing unit is being used, as well as can visually display the station frequency or the like of the selected station when the electronic tuning type receiver is being used.

Combination device having a magnetic recording and reproducing unit and

During preset station selection operation in a digital receiver the station selection switch most recently operated is indicated by a light so as to prevent erroneous operation at the same switch again.

Station selection indicating device

A preset state indicating unit for use in an electronic tuning type receiver generates a visual indication when both a presetting switch and one of a plurality of channel selecting switches have been properly selected. The preset state indicating unit thus insures that tuning information pertaining to a selected station is actually stored in memory during the presetting operation done by the user.

Growing community of inventors

Kawagoe, Japan

Tadashi Kosuga