Tuning device for receivers

Claim 2

A tuning device for receivers comprising a tuning knob means for selecting a desired broadcasting station insulated from the ground and manually operated by an operator to detect an electrostatic field at the operator''s human body, an electrostatic field detection circuit means connected to said tuning knob means and for effecting a switching operation, an electronic switching circuit connected to said electrostatic field detection circuit means and adapted to be controlled to on or off condition in accordance with the output signal from said electrostatic field detection circuit means, said tuning knob means comprises first and second tuning knob members insulated one from the other and made of an electric conductive material, a belt, a tuning circuit element, the latter having a rotating shaft, a rotary shaft secured at its one end to each of said first and second tuning knob members and connected at another end through said belt to said rotating shaft of said tuning circuit element, a first bearing electrically connected to said first tuning knob member and made of an electric conductive material, a second bearing connected to said second tuning knob member, and a bearing holder for supporting said rotary shaft, and said bearing holder made of an insulating material.

Claim 3

A tuning device for receivers comprising a tuning knob insulated from the ground for detecting an electrostatic field established at an operator''s human body to select a desired broadcasting station, an electrostatic field detection circuit means for effecting a switching operation by means of said electrostatic field established at an operator''s human body, an intermediate frequency amplifier circuit, a muting signal detector circuit for detecting presence or absence of a broadcasting signal in said intermediate frequency amplifier circuit, a multiplexer circuit, and an electronic muting switching circuit connected between sAid muting signal detector circuit and at least one of two circuits consisting of said intermediate frequency amplifier circuit and said multiplexer circuit and operatively connected to said electrostatic field detection circuit means and adapted to be controlled to on or off condition by means of the output signal from said electrostatic field detection circuit means.

Claim 4

A tuning device for receivers comprising a tuning knob insulated from the ground for detecting an electrostatic field established at an operator''s human body to select a desired broadcasting station, an electrostatic field detection circuit means for effecting a switching operation by means of said electrostatic field established at an operator''s human body, an intermediate frequency amplifier circuit, a muting signal detector circuit for detecting presence or absence of a broadcasting signal in said intermediate frequency amplifier circuit, a multiplexer circuit, and an electronic muting switching circuit connected between sAid muting signal detector circuit and at least one of two circuits consisting of said intermediate frequency amplifier circuit and said multiplexer circuit and operatively connected to said electrostatic field detection circuit means and adapted to be controlled to on or off condition by means of the output signal from said electrostatic field detection circuit means.

Claim 5

A tuning device for receivers comprising a tuning knob including first and second tuning knob members electrically insulated one from the other and each made of an electric conductive material, first and second electrostatic field detection circuit means each for effecting a control operation in response to an electrostatic field respectively, arising when an operator places his fingers in contact with at least one of said tuning knob members at the time of selecting a desired broadcasting station, a first and second intermediate frequency amplifier circuit, a muting signal detector circuit for detecting presence or absence of broadcasting signal in said first intermediate frequency amplifier circuit, a multiplexer circuit, a level control circuit connected between said muting signal detector circuit and at least one of two circuits consisting of said second intermediate frequency amplifier circuit and said multiplexer circuit and adapted to be controlled by the output from each of said first and second electrostatic field detection circuit means.

Claim 6

A tuning device for receivers comprising a tuning knob including first and second tuning knob members electrically insulated one from the other and each made of an electric conductive material, first and second electrostatic field detection circuit means each for effecting a control operation in response to an electrostatic field respectively, arising when an operator places his fingers in contact with at least one of said tuning knob members at the time of selecting a desired broadcasting station, a first and second intermediate frequency amplifier circuit, a muting signal detector circuit for detecting presence or absence of broadcasting signal in said first intermediate frequency amplifier circuit, a multiplexer circuit, a level control circuit connected between said muting signal detector circuit and at least one of two circuits consisting of said second intermediate frequency amplifier circuit and said multiplexer circuit and adapted to be controlled by the output from each of said first and second electrostatic field detection circuit means.

Claim 7

A tuning circuit for receivers comprising a tuning knob including first and second tuning knob members electrically insulated one from the other and made of an electric conductive material, first and second electrostatic field detection circuit means each for effecting a switching operation when an operator places his fingers in contact with at least one of said knob members at the time of selecting a desired broadcasting station, a first and second intermediate frequency amplifier circuit, a muting signal detection circuit for detecting the presence or absence of the broadcasting signal in said first intermediate frequency amplifier circuit, a multiplexer circuit, an electronic muting switching circuit connected between the output terminal of said muting signal detection circuit and at least one of said second intermediate frequency amplifier circuit and said multiplexer circuit and on or off controlled by means of said first electrostatic field detection circuit means, and a local oscillation circuit, a detector circuit operatively connected between said second intermediate frequency amplifier circuit and said multiplexer circuit, an AFC electronic switch connected between said local oscillation circuit and said detector circuit and on-off controlled by means of said second electrostatic field detection circuit means.

Claim 8

A tuning circuit for receivers comprising a tuning knob including first and second tuning knob members electrically insulated one from the other and made of an electric conductive material, first and second electrostatic field detection circuit means each for effecting a switching operation when an operator places his fingers in contact with at least one of said knob members at the time of selecting a desired broadcasting station, a first and second intermediate frequency amplifier circuit, a muting signal detection circuit for detecting the presence or absence of the broadcasting signal in said first intermediate frequency amplifier circuit, a multiplexer circuit, an electronic muting switching circuit connected between the output terminal of said muting signal detection circuit and at least one of said second intermediate frequency amplifier circuit and said multiplexer circuit and on or off controlled by means of said first electrostatic field detection circuit means, and a local oscillation circuit, a detector circuit operatively connected between said second intermediate frequency amplifier circuit and said multiplexer circuit, an AFC electronic switch connected between said local oscillation circuit and said detector circuit and on-off controlled by means of said second electrostatic field detection circuit means.

Claim 9

A tuning device for receivers comprising a tuning knob comprising a plurality of tuning knob members each made of an electric conductive material and electrically insulated one from the other, one of said tuning knob members being rotated for selecting a desired broadcasting station, first and second electrostatic field detection circuit means for effecting switching operations in dependency upon the condition of contact of the operator''s fingers with said plurality of tuning knob members at a time of selecting a desired broadcasting station, a first and second intermediate frequency amplifier circuits, an electronic muting signal detection circuit means for detecting the presence and absence of the broadcasting signal in said first intermediate frequency amplifier circuit and for effecting a level control by means of the output from both said electrostatic field detection circuit means, a multiplexer circuit, and an electronic muting switching circuit connected between the output terminal of said muting signal detector circuit means and at least one of said second intermediate frequency amplifier circuit and said multiplexer Circuit and adapted to be on-off controlled by means of the output from said first and second electrostatic field detection circuit means.

Claim 10

A tuning device for receivers comprising a tuning knob comprising a plurality of tuning knob members each made of an electric conductive material and electrically insulated one from the other, one of said tuning knob members being rotated for selecting a desired broadcasting station, first and second electrostatic field detection circuit means for effecting switching operations in dependency upon the condition of contact of the operator''s fingers with said plurality of tuning knob members at a time of selecting a desired broadcasting station, a first and second intermediate frequency amplifier circuits, an electronic muting signal detection circuit means for detecting the presence and absence of the broadcasting signal in said first intermediate frequency amplifier circuit and for effecting a level control by means of the output from both said electrostatic field detection circuit means, a multiplexer circuit, and an electronic muting switching circuit connected between the output terminal of said muting signal detector circuit means and at least one of said second intermediate frequency amplifier circuit and said multiplexer Circuit and adapted to be on-off controlled by means of the output from said first and second electrostatic field detection circuit means.

Claim 11

A tuning device for receivers as set forth in claim 5, further comprising a first transistor and a pair of transistors, said muting signal detection circuit means consists of said first transistor for amplifying the output from said first intermediate frequency amplifier circuit and of said pair of transistors on-off controlled by means of the output from said first and second electrostatic field detection circuit means for controlling the degree of amplification of said first transistor.

Claim 12

A tuning device for receivers, as set forth in claim 5, wherein said electronic muting switching circuit includes two transistors connected with the emitter of one of said two transistors connected to the collector of the other of said two transistors between an input terminal of said second intermediate frequency amplifier circuit and the ground, the base of said one of said two transistors being connected to the output terminal of said muting signal detector circuit means and the base of said other of said two transistors being connected in common to both the output terminals of said first and second electrostatic field detection circuit means.

Claim 13

A tuning device for receivers comprising a tuner for a receiver, said tunner having a tuning circuit, a loud speaker, an audio frequency amplifier for amplifying the output signal from said tuner and connected to said loud speaker to produce sound from said loud speaker, a tuning knob insulated from the ground for detecting an electrostatic field established at an operator''s human body, a switching circuit, connected to said tuning circuit, an electrostatic field detection circuit means operatively connected to said tuning knob for effecting an on switching operation of said switching circuit by means of the electrostatic field established at the operator''s human body when the operator touches his fingers with said tuning knob, and an indicator device operatively connected to said switching circuit and for indicating the output level of said tuning circuit of said tuner when said switching circuit is on.

Claim 14

A tuning device for receivers comprising a tuner for a receiver, said tunner having a tuning circuit, a loud speaker, an audio frequency amplifier for amplifying the output signal from said tuner and connected to said loud speaker to produce sound from said loud speaker, a tuning knob insulated from the ground for detecting an electrostatic field established at an operator''s human body, a switching circuit, connected to said tuning circuit, an electrostatic field detection circuit means operatively connected to said tuning knob for effecting an on switching operation of said switching circuit by means of the electrostatic field established at the operator''s human body when the operator touches his fingers with said tuning knob, and an indicator device operatively connected to said switching circuit and for indicating the output level of said tuning circuit of said tuner when said switching circuit is on.

Claim 15

A tuning device for receivers as set forth in claim 8 wherein said indicator device comprises a lamp and a scale provided on a dial, said lamp for illuminating said scale, a meter means connected in parallel with said lamp for indicating said output level of said tuning circuit.