Murata Manufacturing Co., Ltd.

Yoji Maeda

Katsuo Ito

Bunjiro Murata

Eiichi Hibino

Kazunori Kinoshita

Akimasa Matsushima

Kazunori Yoshimura

Masao Uno

Kazuhiro Tsuji

Sadao Kotera

Hiroyuki Tetsuno

Yoshikazu Shimamura

A CATV tuner includes a metallic housing having first through fourth partitioned chambers. In the first through fourth partitioned chambers, a data circuit, an input filter circuit, a first mixer circuit, a first local oscillation circuit, a first intermediate frequency circuit, and other elements are housed. In the fifth partitioned chamber, a second intermediate circuit and an IC including a second local oscillation circuit are housed. With this configuration, the CATV tuner defines an up/down tuner. The third partitioned chamber in which the first local oscillation circuit is housed and the fifth partitioned chamber in which the second local oscillation circuit is housed are located adjacent to each other. Lines and terminals are used both for a first PLL circuit and a second PLL circuit.

CATV tuner and one-chip IC used therein

A tuner includes an input terminal, first to fourth band-pass filters, an automatic gain controller, first to third amplifiers, first and second mixers, first and second voltage controlled oscillators, first and second PLL ICs, a reference oscillator circuit, and an output terminal. The second PLL IC and the reference oscillator circuit are connected through a capacitor and an amplifier. An amplifier for reference oscillation, included in the first PLL IC is connected to the reference oscillator circuit through an inductor that defines an inductance device.

Tuner

An electronic component is mounted on one major surface of a dual side wiring substrate. A terminal is press-fitted into a mounting hole in the dual side wiring substrate from the one major surface side to be temporarily fixed in the substrate, and an electronic component is mounted on the other major surface of the dual side wiring substrate after soldering paste is applied. A frame having a plurality of bent pieces extending inwardly is mounted onto the dual face wiring substrate from a position above the substrate so that the bent pieces abut against the pattern of the dual side wiring substrate. The terminal press-fitted from the one major surface side, the electronic component mounted on the other major surface, and the frame are soldered simultaneously by a reflow method.

Method of manufacturing circuit module

A feedthrough capacitor arrangement which comprises a frame having a first recess, printed circuit boards disposed in the vicinity of the frame, a feedthrough capacitor having an outer electrode and a central electrode placed in the first recess and a shield member for pressing the feedthrough capacitor placed in the first recess thereby to hold the feedthrough capacitor in association with the frame. In this arrangement, the outer electrode of the feedthrough capacitor is soldered to the frame and to the shield member while the central electrode is soldered to conductor patterns on the printed circuit boards.

Feedthrough capacitor arrangement

A television tuner comprises a rotary switching shaft, switching plates associated with the rotary switching shaft, and an input tuning portion, an interstage tuning portion and a frequency converting portion coupled to the switching plates and adapted for channel selection by means of the rotary switching shaft. An additional plate is provided between one switching plate associated with the interstage tuning portion and another switching plate associated with the frequency converting portion. The additional plate is provided with a surface acoustic wave device performing the function of a video intermediate frequency filter and with an integrated circuit including a video intermediate frequency amplifier and a video detector.

Rotary switch type television tuner

A VHF television tuner for selection of a broadcasting television signal through mechanical switching selection of inductance coils, comprising; a tuner casing; a mechanical channel selection switch arrangement provided in said casing and including a rotatably mounted channel selection shaft for selection of inductance coils by rotation of said shaft; a radio frequency amplifier operatively coupled to the selected inductance coils for selectively amplifying a desired radio frequency signal; a local oscillator operatively coupled to said selected inductance coils for providing a local oscillation frequency signal, the frequency of which is different by a given frequency difference from said selectively amplified radio frequency signal; a mixer responsive to the radio frequency signal from said radio frequency amplifier and the local oscillation frequency signal from said local oscillator for providing an intermediate frequency signal; and an intermediate frequency tuned circuit for selectively withdrawing said intermediate frequency signal, said intermediate frequency tuned circuit comprising an intermediate frequency transformer, said intermediate frequency transformer comprising an intermediate frequency coil wound around a bobbin having a given axis and a magnetic core threadably inserted in said bobbin for adjustment of the inductance value of said intermediate frequency coil by rotation of said magnetic core about said axis of said bobbin, said intermediate frequency transformer being provided in said casing such that the axis of said bobbin is oriented in the direction substantially parallel to the axial direction of said channel selection shaft, said casing being formed of an aperture at the position in alignment with the axis of said bobbin, whereby access to said intermediate frequency transformer is allowed from the outside of said casing for adjustment of the inductance value of said intermediate frequency transformer.

VHF Television tuner with easy/flexible access

A VHF television tuner circuit for selection of a television signal through mechanical selection of inductance coils comprises a first terminal for receiving a VHF television signal comprising a high and low VHF channel signals; a second terminal for receiving a UHF/VHF converted television signal; a mechanical channel selection switch arrangement for selection of a plurality of channel positions by rotation of a channel selection shaft said mechanical channel selection switch arrangement comprising a radio frequency coil switching stage and an oscillation coil switching stage; a radio frequency coil means coupled to the radio frequency coil switching stage; an oscillation coil coupled to the oscillation coil switching stage; a radio frequency amplifier coupled to the radio frequency coil switching stage for selectively amplifying a desired radio frequency signal; a local oscillator coupled to the oscillation coil switching stage for providing a local oscillation frequency, the frequency of which is different by a given frequency difference from the selectively amplified radio frequency signal; and a mixer responsive to the radio frequency amplifier and the local oscillator for providing an intermediate frequency signal. The radio frequency coil switching stage comprises a first stage radio frequency coil switch for selectively grounding or disconnecting the transmission path from said first terminal and for selecting a radio frequency coil corresponding to each VHF channel, and a second stage radio frequency coil switch selectably connectable to the radio frequency coil selected by the first stage radio frequency coil switch for selectively connecting said second terminal to said radio frequency amplifier, and for selectively connecting various capacitors in various ways to form a resonance circuit for selecting a desired radio frequency.

Growing community of inventors

Ishikawa, Japan

Yoji Maeda