JPH02283127A - Electronic tuner - Google Patents

Abstract

PURPOSE:To attain impedance matching with a single body and to eliminate the need for impedance matching again after the installation of the tuner onto a television receiver by integrating a tuner section, a changeover circuit and 1st and 2nd antenna input sections to constitute the tuner. CONSTITUTION:A 1st antenna 7A connects to a 1st antenna input section 7 and a 2nd antenna 8A are connected to a 2nd antenna input section 8. A changeover means 9 is thrown to the position of an input section 8 normally and thrown to the position of the input section 7 mechanically when the antenna 7A is connected to the input section 7 when the reception frequency is increased, a driving means 11 of a changeover switch 12 switches the switch 12 opposite to a coil 13 to correct the antenna length shorter. A lower figure shows the external appearance of the electronic tuner, the turner section 10, the driving means 11, the switch 12 and the coil 13 or the like are contained in a shield case 14 and a plug section 16 of input sections 7, 8 is placed on a printed circuit board 15 projecting from the case 14.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electronically tuned tuner used in television receivers, audio receivers, and the like.

2. Description of the Related Art Conventionally, this type of electronic tuning tuner has been designed as shown in FIG.

In FIG. 3, 1 is an electronic tuner, 2 is a main 7 board for a television receiver (not shown), 3 is a power supply circuit for the tuner, 4 is a power supply circuit for an antenna circuit, and 5 is a switching circuit including an antenna circuit. , 6 is an external antenna jack.

The external antenna jack 6 has a first. There was a second antenna input, in which an input signal selected by a switching circuit 6 comprising an antenna circuit was supplied to the electronically tuned tuner 1 .

Problems to be Solved by the Invention However, in the above configuration, the electronic tuning tuner 1 merely has a tuner section, and the switching circuit 5 including the antenna circuit and the external antenna jack 6 are separately provided on the main board 2. Therefore, there was a problem in that it was difficult to achieve impedance matching between the tuner section and the switching circuit 6 including the antenna circuit.

The present invention solves the above conventional problems, and aims to provide an electronically tuned tuner that does not require impedance matching after installation in a television receiver.

Means for Solving the Problems In order to achieve this object, the present invention has the following features: 1. a second antenna input section; and a switching means for selectively connecting the first and second antenna input sections and the tuner section; The second antenna input section, tuner section, and switching means are integrated.

Function: With this configuration, the tuner section, the switching circuit, the first and second
Since the antenna input section of the is integrated, if impedance matching is performed with this, there is no need to perform impedance matching after installing the electronic tuner in the television receiver.Example The following is an example of the present invention. will be explained with reference to the drawings.

In FIG. 1, 7 is a first antenna input section to which seven first antennas are connected, and 8 is a second antenna input section to which eight second antennas are connected. Reference numeral 9 denotes a switching means which is normally connected to the second antenna input section side, and when seven first antennas are connected to the first antenna input section 7, it is mechanically switched to the second antenna input section 7 side. It's starting to change. 10 is a tuner unit, 11 is a driving means for a changeover switch 12, and the changeover switch 12 is installed on the opposite side of the coil 13 in order to shorten the antenna length when the receiving frequency becomes high.
Switch.

FIG. 2 shows the external appearance of the electronically tuned tuner of this embodiment, and shows the tuner section 10 of FIG. Drive means 11 selector switch 12
．． The coil 13 and the like are provided in a shield case 14, and the plug portions 16 of the first and second antenna input portions 7, 8 are installed on a printed circuit board 15 protruding from the shield case 14. The present invention includes a tuner section, a switching circuit, and a first,
Since the second antenna input section is integrated,
If impedance matching is achieved with this unit alone, there is no need to perform impedance matching again after installation in the television receiver.

Further, the main board 2 of the conventional antenna circuit power supply circuit 4 shown in FIG. 3 is not required.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention, FIG. 2 is a perspective view thereof, and FIG. 3 is a perspective view of a conventional example. 7.8... 1st. Second antenna input section, 9...
...Switching means, 1o...Tuner section. Name of agent: Patent attorney Shigetaka Awano and 1 other person 1st
Figure A Fable 2 Figure 3! /

Claims (1)

[Claims] comprising first and second antenna input sections, and switching means for selectively connecting the first and second antenna input sections and a tuner section, the first and second antenna input sections, the tuner section, Electronic tuning tuner with integrated switching means.