JPS6221075Y2 - - Google Patents

Description

[Detailed description of the invention] The invention is based on, for example, a magnetic recording/reproducing device (hereinafter simply referred to as
VTR) and television receivers (hereinafter simply referred to as
It pertains to a simple television transmitter used as an interface between
In a simple television transmitter in which a video signal input wiring pattern, an audio signal input wiring pattern, and a power input wiring pattern are arranged in parallel on a signal input terminal section provided on a part of a printed wiring board,
By forming a ground pattern between each wiring pattern, interference between signals input to each wiring pattern can be prevented, and stable and good quality can be achieved.
The purpose is to obtain a TV broadcast output signal.

FIG. 1 shows a block diagram of a simple television transmitter. A dotted line 1 indicates a case in which each circuit block is incorporated. Tv and Ts are terminals to which video signals and audio signals are supplied, respectively, and Vcc
indicates the terminal to which power is supplied. After the video signal from the terminal Tv is amplified, the main carrier signal from the oscillator is amplitude-modulated, and the modulated wave signal is supplied to the sum circuit. The audio signal from the other terminal Ts is
A 4.5 MHz subcarrier is frequency modulated, its output amplitude modulates the main carrier signal from the oscillator, the output modulated wave signal is supplied to the sum circuit, and the output signal is output to the output terminal To. , and then connected to the antenna terminal of the TV (not shown).

Since video and audio signals are supplied to each of the Tv and Ts terminals above, if the distance between these terminals is small or if the terminals are not shielded, high frequency signals may be generated between the terminals. There is a problem that the signals may interfere with each other. Further, such a problem also occurs between these terminals Tv or Ts and the power supply input terminal, and in particular, when a video or audio signal is mixed into the power supply line, a problem arises in that oscillation and modulation become unstable.

The present invention solves these problems with an extremely simple configuration, and one embodiment thereof will be described below with reference to the drawings.

FIG. 2 shows a rear perspective view with the cover removed of a simple television transmitter in which the circuit block described above is incorporated.

1 is a simple television transmitter case, 3
Reference numeral 4 indicates a printed circuit board, 4 indicates an external terminal projecting outside the case through the case opening window H, and 6 indicates a male connector having a plug pin attached to the upper surface of the external board. The portions of the board 3 shown in a satin pattern indicate the ground pattern G. The video signal supply terminal Tv, the power supply terminal Vcc, and the audio signal supply terminal Ts are each provided with a wiring pattern on the external board 4 extending from the board 3 inside the case 2 orthogonally to the case opening window H, and connecting the ends of these patterns. A plug pin terminal of the connector 6 is soldered to the external board 4 by penetrating it from the surface thereof.

11, 12 between terminals Vcc and Ts and between Ts and Tv
There are also two loose terminals shown at 13 and 14 which are connected by soldering to two ground patterns _G1 and _G2, respectively. Pc, Ps and Pv are Vcc, Ts and Tv
This is the wiring pattern connected to each terminal.
The earth patterns G ₁ and G ₂ are provided with protrusions 7 and 8 on the case at the case opening window H, and the protrusions 7 and 8 and the earth patterns G ₁ and G ₂ are soldered to each other. It is electrically connected to another ground pattern 3 shown in a matte pattern through the ground pattern. _S1 ,
S ₂ and S ₃ are the parts where the earth pattern 3 and the case 1 are soldered.

As mentioned above, the ground pattern G1 is interposed between the power input wiring pattern Pc and the audio signal input wiring pattern Ps, and the ground pattern _G1 is interposed between the video signal input wiring pattern Pv and the audio signal input wiring pattern Ps. A ground pattern _G2 is interposed between the signal input terminals, and these ground patterns have the same effect as shielding between the respective signal input terminals, and can prevent signal interference between the respective terminals.

Next, a modification of the above-mentioned FIG. 2 is shown in FIG. 3 and will be described. The same parts as those in FIG. 2 will be described with the same reference numerals.

FIG. 3 shows a perspective view with the back cover of the case removed, in which 1 is the case of a simple television transmitter, 3 is a printed circuit board, 4 is an external terminal protruding from the case opening 5 outside the case, and 6 is a perspective view of the case with the back cover removed. 1 and 2 respectively show male connectors with plug pins attached to the top surface of the external board. The portions of the board 3 shown in a matte pattern indicate ground patterns. The video signal supply terminal Tv, the power supply terminal Vcc, and the audio signal supply terminal Ts are each provided with wiring patterns on the external board 4 extending from the board 3 inside the case 2 at right angles to the case opening 5. A plug pin terminal of the connector 6 is soldered to the external board 4 by penetrating it from the surface thereof.

The ground patterns _G1 and _G2 arranged between the wiring patterns Pc and Ps and Ps and Pv are formed integrally with the ground patterns arranged around them, so as shown in Fig. 2 above, There is no need for special grounding by other means. It should be noted that the ground patterns G ₁ and G ₂ do not need to be connected to both the ground patterns arranged above and below, but the shortest distance between the tip end side (top) of the external board 4 or the ground patterns G ₃ and G ₄ Ground pattern provided on (bottom)
It may be connected to only one of them, but it is preferable that it be connected to both.

Note that the arrangement order of the terminals Tv, Ts, and Vcc is not limited to that in the embodiment, and may be any other arrangement order.

As described above, the present invention provides a simple television transmitter having a signal input terminal section in which a video signal input wiring pattern, an audio signal input wiring pattern, and a power input wiring pattern are arranged in parallel on a part of a printed wiring board. Since a ground pattern is provided between each wiring pattern, this ground pattern has a shielding effect between each signal input wiring pattern, and as a result, between each signal input terminal,
Electric signal interference is eliminated, oscillation and modulation are stabilized, and a stable and good television broadcast output signal can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a simple television transmitter, and FIG. 2 is a rear perspective view of a simple television transmitter according to an embodiment of the present invention.
FIG. 3 shows a rear perspective view of a transmitting device showing a modification of FIG. 2, respectively. 1...Case, 3...Case internal board, 4...External board, 5...Case opening, 6...Connector, 7, 8...Protrusion, Tv...Video signal supply terminal, Ts... Audio signal supply terminal, Vcc...power supply terminal, To...output terminal, Pv, Pc, Ps...
Wiring pattern, G, G _1~4 ...Earth pattern,
H...Case opening window.

Claims (1)

[Scope of utility model registration request] In a simple television transmitter having a signal input terminal portion in which a plurality of signal input wiring patterns and a power input wiring pattern are arranged in parallel on a part of a printed wiring board, the plurality of signal input wiring patterns and the power input wiring pattern are arranged in parallel. A simple television transmitting device characterized in that a ground pattern is provided between at least a plurality of signal input wiring patterns among adjacent wiring patterns of each pattern.