JPH07327176A - Bs tuner - Google Patents

Abstract

PURPOSE:To avoid interference between a tuner section and a video image processing section by forming a signal line to an external connection terminal of a printed circuit board and an earth line to the opposite side. CONSTITUTION:A slot 7 used to separate a tuner block X and a printed circuit board 3 is formed on the front side of the board 3, and a tuning section, a demodulation section and a detection section are arranged and mounted onto the block X. Furthermore, a video image processing section including a video amplifier separating and amplifying a synchronizing signal and a video signal is arranged to a video signal block Y oaf the board 3 and a video output of the video image processing section is outputted to a video terminal 8 arranged to the same side of an external connection terminal 5. The tuner block X and the video signal block Y are interconnected by a signal line 9 formed to the same side of the terminals 5, 8 and an earth line parted from the line 9 with a slot. Then the block X of the board 3 is enclosed by a shield case 4 and the tuning section, the demodulation section and the detection section are completely shielded by the case 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a BS tuner used for AV equipment such as a television set and a video tape recorder.

[0002]

As is well known, in an AV device such as a television set or a video tape recorder that receives a stationary satellite radio wave, a BS tuner that detects the stationary satellite radio wave and separates it into a video signal and an audio signal is used. But the conventional B
The S tuner has a structure and a circuit configuration as shown in FIGS.

That is, as shown in FIG. 4, a conventional BS tuner has a pair of connectors 1A and 2A respectively connected to a BS antenna and AV equipment such as a television set, and is provided on the surface of a circuit board 3A thereof. As shown in FIG. 5, the tuning section D, the demodulation section F,
The detection unit K is arranged. The entire circuit board 3A is housed in a shield case 4A composed of a shield case body 4a, a front cover 4b, and a back cover 4c. The shield case 4A allows the tuning section D, the demodulation section F, and the detection section K to be detected.
Electromagnetic and magnetic separation between each other and the external magnetic field is achieved.

A plurality of external connection terminals 5A are arranged on one side of the circuit board, and these external connection terminals 5A are arranged.
The video signal and the audio signal are output to the video processing unit E and the audio processing unit O of the AV device via A.

[0005]

By the way, in the BS tuner having the above-mentioned structure, the recent new function AV
With the development of the equipment, the video processing portion E including the video signal amplifier portion, which has conventionally constituted a part of the AV equipment, is
It is often requested that the S tuner is mounted on the circuit board 3A. However, in a BS tuner that satisfies such requirements, one circuit board 3A includes up to the video processing section E. Since it is mounted, a subtle mutual interference between the tuner unit and the video processing unit E is likely to occur, and it is difficult to obtain a highly reliable BS tuner. Also,
If a BS tuner equipped with a video processing unit E is newly designed, the shield case body 4 with a relatively high manufacturing cost
Since the dies for the a, the front cover 4b, and the back cover 4c have to be manufactured again, there is a problem that the product cost becomes very expensive.

In view of the problems of the conventional BS tuner as described above, the first object of the present invention is to mount a video processing section on a single circuit board, and the tuner section and the video processing section E are provided. It is to obtain a BS tuner structure without mutual interference between and. A second object of the present invention is to provide a BS tuner that can achieve the first object, and a BS tuner with an image processing unit that can be used together with a shield case that has been used conventionally.

[0007]

According to the present invention, the first object is to divide the surface of a circuit board into a tuner block and a video signal block which are adjacent to each other in the arrangement direction of the external connection terminals on one side, and receive them. A radio wave tuning unit, a demodulation unit, and a detection unit are arranged in the tuner block, a video processing unit for amplifying the video signal detected by the detection unit is arranged in the video signal block, and the external connection terminal side is provided. This is achieved by a BS tuner in which the detection section and the video processing section are connected to each other through the signal line and the ground line on the side opposite to the signal line. The second object is a BS tuner that can achieve the first object, and is divided by a slot formed at a boundary portion between the tuner block of the circuit board and the video signal block, and the slot. And a shield case that surrounds the entire tuner block of the circuit board.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the embodiments of the present invention will be described below with reference to FIGS. As understood from FIG. 1, the BS tuner of the present invention includes a pair of connectors 1 and 2 respectively connected to an AV device such as a BS antenna and a television set, and the surface of a circuit board 3 thereof is Tuner blocks X adjacent to each other in the alignment direction of the external connection terminals 5
And a video signal block Y. That is, as shown in FIG. 3, a vertical slot 7 for separating the tuner block X and the circuit board 3 is formed on the surface of the circuit board 3, and a signal received from a BS antenna is input to the tuner block X. A tuning unit D, a demodulation unit F for demodulating a received wave of a frequency tuned by the tuning unit D to a processable frequency, and a detection unit K for extracting a video signal and an audio signal from the demodulated wave are arranged and mounted.

Further, although not shown in the drawing, the video signal block Y of the circuit board 3 is provided with a video processing section E including a video amplifier for separating and amplifying the sync signal and the video. The video output is output to the video terminal 8 arranged on the same side as the external connection terminal 5. The audio output separated by the detection unit K is output from a part of the external connection terminal 5 to the audio processing unit O of the V device.

As can be seen from FIG. 3, between the tuner block X and the video signal block Y, a signal line 9 formed on the same side as the external connection terminal 5 and the video terminal 8 and the slot. It is connected by a ground line 10 which is separated from the signal line 9 at 7.

A part of the circuit board 3 of the BS tuner of the illustrated embodiment, that is, the tuner block X is surrounded by a shield case 4 which is the same as the conventional one, and the shield case 4 subtly adjusts the tuning section D and the demodulation section F. The detection section K is completely shielded. That is, the shield case body 4a manufactured in the shape of a rectangular frame is formed with slits 11 that can pass through the signal line corresponding portion and the earth line corresponding portion of the circuit board 3, and the front and back surfaces of the shield case body 4a are Front cover 4b and rear cover 4 similar to conventional ones
covered with c. The video signal block Y having a relatively low frequency can be prevented from inputting a disturbance signal only by forming an earth electrode layer (not shown) on the entire back surface of the circuit board 3.

Since the BS tuner according to the illustrated embodiment has the above-described structure, the tuning section D,
The demodulation section F, the detection section K, and the video processing section E are mounted with electrical parts, and the tuner block X of the circuit board 3 is covered with the shield case 4 to complete the process. In this completed state, only the signal line 9 and the ground line 10 are drawn out of the shield case 4, so that the delicate tuner block X can be completely shielded by the shield case 4. Further, since the tuner block X of the circuit board 3 has the same size and shape as the circuit board of the conventional BS tuner, the conventional shield case body 4a, the front cover 4b, and the back cover 4c can be diverted, and therefore the specifications are expensive. It is no longer necessary to manufacture a new mold.

[0013]

As is apparent from the above description, according to the present invention, the signal line is provided on the external connection terminal side of the circuit board.
Since the ground line is formed on the opposite side, it is possible to prevent subtle interference between the tuner part and the image processing part, and it is possible to use the conventional shield case together, so it is inexpensive to change the specifications of the BS tuner that also includes the image processing part. There is an effect that can correspond to.

[Brief description of drawings]

FIG. 1 is an overall perspective view of a BS tuner of the present invention shown with a part cut away.

FIG. 2 is a block diagram of the BS tuner.

FIG. 3 is a plan view of a circuit board used in the BS tuner.

FIG. 4 is an overall perspective view of a conventional BS tuner with a part cut away.

FIG. 5 is a block diagram of the BS tuner.

[Explanation of symbols]

 3 circuit board 4 shield case 5 external connection terminal 7 slot 9 signal line 10 earth line E video processing unit D tuning unit F demodulation unit K detection unit X tuner block Y video signal block

Claims (2)

[Claims] 1. A surface of a circuit board is divided into a tuner block and a video signal block which are adjacent to each other in the arrangement direction of external connection terminals on one side, and a tuning section, a demodulation section and a detection section for received radio waves are arranged in the tuner block. An image processing unit for amplifying the image signal detected by the detection unit is arranged in the image signal block, and the detection unit is provided with a signal line on the external connection terminal side and an earth line on the opposite side of the signal line. And a video processing unit connected to the BS.
Tuner. 2. A slot formed at the boundary between the tuner block of the circuit board and the video signal block, and a shield case surrounding the entire tuner block of the circuit board partitioned by the slot. The BS tuner according to claim 1.