JP2003304162A - Receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce performance deterioration due to undesired radiation and to maintain a cost advantage in a receiver with a plurality of built-in tuners. <P>SOLUTION: At least two tuners 21 and 22 are provided. The tuners 21 and 22 are configured by mounting prescribed parts 211 and 221 on both-surface printed boards 210 and 220 respectively. At this time, one surfaces 21A and 22A of the both-surface printed boards 210 and 220 are mounting surfaces for the parts 211 and 221, while the other surfaces 21B and 22B are a ground surface over almost all of the surfaces. The mounting surface 21A of the both- surface printed board 210 and the mounting surface 22A of the both-surface printed board 220 are plane symmetrical, and the both-surface printed boards 210 and 220 are arranged in the receiver such that the ground surfaces 21B and 22B face each other. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver including a plurality of tuners.

[0002]

2. Description of the Related Art As a receiving apparatus for digital satellite broadcasting, for example, as shown in FIG. 3, one having two receiving systems and a device for accumulating programs is considered. That is, the digital satellite broadcast is received by the first antenna 11, is down-converted into an intermediate frequency signal, and this intermediate frequency signal is supplied to the first tuner 21 of the receiving device 20 and converted into a baseband signal. At the same time, the first TS (transport stream) is output by performing processing such as demodulation and error correction, and this TS is supplied to the switching circuit 23.

The second antenna 12 receives the second digital satellite broadcast and down-converts it into an intermediate frequency signal. The intermediate frequency signal is supplied to the second tuner 22 and the first tuner 21. The second TS is output by the same process as the above, and this TS is supplied to the switching circuit 23.

A HDD 24 is connected to the switching circuit 23 as a device for storing programs. Either the TS output from the tuner 21 or the TS output from the tuner 22 is operated according to the user's operation. One of them is recorded (stored).

From the switching circuit 23, any one of the TSs output from the tuners 21 and 22 and the TSs read from the HDD 24 is selected and extracted from the switching circuit 23 according to the user's operation. The TS is supplied to the MPEG decoder 25 and decoded into a digital video signal and a digital audio signal.

Then, the decoded digital video signal is supplied to, for example, an NTSC encoder circuit 26 to be encoded into a digital video signal in the NTSC system, and this signal is supplied to a D / A converter circuit 27V and an analog NTSC video signal. D / A converted to and output to the output terminal 28V. Further, the digital audio signal decoded by the MPEG decoder 25 is supplied to the D / A converter 27S, D / A converted into an original analog audio signal, and taken out to the output terminal 28S.

Further, the system control circuit 29 is configured to have a microcomputer, and the control signal is supplied from the system control circuit 29 to each circuit in accordance with a user's operation.

The tuners 21 and 22 are constructed as shown in FIGS. 4 and 5, for example. That is, the tuners 21 and 22 have the same structure, and various components 32 and 33 such as ICs are mounted on one surface and the other surface of the rectangular double-sided printed circuit board 31. Further, frame-shaped shield plates 34 and 35 are provided so as to surround the high frequency part of the printed circuit board 31, and the shield plates 34 and 35 have dish-shaped shield lids 36 and 35.
7 is covered (in FIG. 4, the shield lid 36 is removed).

An antenna input connector 38 and a connector pin 39 are provided on one short side and a long side of the printed board 31 in a direction parallel to the printed board 31.

As shown in FIG. 5, the tuners 21 and 22 configured as described above are parallel to each other, and the connectors 38 and 38 are connected to the rear panel 4 of the receiver 20.
It is provided on the main printed circuit board 42 so as to project from 1. At this time, although not shown, two connectors are provided on the printed circuit board 42, and the connector pins 39, 39 of the tuners 21, 22 are connected to these connectors.
Is inserted, whereby the tuners 21 and 22 are connected to the printed circuit board 42.

Therefore, according to this receiving device 20,
One of the tuners 21 and 22 can output the video signal and audio signal of the received broadcast to the terminals 28V and 28S to watch the broadcast. And at this time,
The program being viewed can be recorded in the HDD 23, or the back program can be received by the other of the tuners 21 and 22 and recorded in the HDD 24 for viewing. In addition, HDD2
You can also watch the program recorded in 4.

[0012]

By the way, the tuner 2
When the tuners 1 and 22 are configured as shown in FIGS. 4 and 5, when the tuner 21 and the tuner 22 are close to each other, unnecessary radiation from the tuner 21 jumps into the tuner 22 and vice versa. Mutual interference occurs because unnecessary radiation from the tuner 22 jumps into the tuner 21. As a result, the bit error rate of the TS output from both tuners 21 and 22 deteriorates, and performance is degraded. I will invite you.

Therefore, as described above, the tuners 21 and 22 shield their high frequency parts from the shield plates 34 and 35.
And the shield lids 36 and 37 are sealed to prevent mutual interference even if the tuner 21 and the tuner 22 are arranged close to each other.

However, two sets of shield plates 34 and 35 and shield covers 36 and 3 are provided for each of the tuners 21 and 22.
If 7 is provided, the number of shield members increases, which increases the cost. Of course, tuner 21 and tuner 22
Although the influence of mutual interference can be reduced even if they are arranged on the main board 42 sufficiently apart from each other, in that case, the interval between the two connectors 38, 38 also becomes wide, and the receiving device 20
Design becomes unrealistic.

The present invention is intended to reduce the performance deterioration due to unnecessary radiation in a receiving device incorporating a plurality of tuners, and at the same time, to maintain the cost advantage.

[0016]

According to the present invention, for example, at least first and second tuners are provided, and the first and second tuners each have a double-sided printed circuit board and a predetermined component. In the double-sided printed circuit board, one surface thereof is a mounting surface of the component, and almost the other surface is a grounding surface.
The mounting surface of the double-sided printed circuit board and the mounting surface of the second double-sided printed circuit board are plane-symmetrical, and the first and second double-sided printed circuit boards are arranged so that the ground planes face each other. The receiving device is arranged at. Therefore, the first and second double-sided printed circuit boards are shielded from each other by their ground planes, and unnecessary radiation from each is suppressed.

[0017]

1 and 2 show an embodiment of the present invention. FIG. 1 is a plan view of the tuners 21 and 2 as a single unit, and FIG. 2 is a receiving device of the tuners 21 and 22. It is a top view which makes a part a cross section in the state mounted in 20.

In the tuner 21, the printed board 210 is, for example, a rectangular double-sided board, and a wiring pattern is formed on one surface 21A thereof to mount various components 211 such as ICs. Further, the other surface 21B of the printed circuit board 210 has a conductive pattern formed on almost the entire surface thereof, and is connected to the ground pattern of the component mounting surface 21A so that almost the entire surface is at the ground potential.
Therefore, the other surface 21B is used as a ground surface. Further, on the component mounting surface 21A of the printed circuit board 210, a frame-shaped shield plate 212 is provided so as to surround the high frequency part.

The antenna input connector 218 and the connector pin 219 are mounted on the component mounting surface 21A on one short side and the long side of the printed board 210 in a direction parallel to the printed board 210. At this time, the connector pin 219 is erected on the insulating base portion 219A, and a part 212A of the shield plate 212 is folded back, and the folded back portion 212A causes the insulating base portion 219A of the connector pin 219 to reach the component mounting surface 21A. It can be suppressed.

Further, the tuner 22 is also constructed in the same manner as the tuner 21, and components 210 to 2 of the tuner 21 are provided.
Parts corresponding to 19A are denoted by reference numeral 220 series instead of reference numeral 210 and description thereof is omitted. However, in this case, as can be seen by comparing FIGS. 1A and 1B, the printed circuit board 210 of the tuner 21 and the printed circuit board 220 of the tuner 22 have their component mounting surfaces 21A and 22A.
The wiring pattern A is almost plane symmetric, and the component mounting surface 21
The main components of the components 211 and 221 mounted on A and 22A are arranged substantially plane-symmetrically.

As shown in FIG. 2, the tuners 21 and 22 configured as described above are used for the printed circuit board 21.
1 and the printed circuit board 212 are parallel to each other, the ground plane 21B of the printed circuit board 211 and the ground plane 22B of the printed circuit board 212 face each other, and the connectors 218 and 219 are disposed on the rear panel 41 of the receiver 20.
The main printed circuit board 42 is provided so as to protrude from the main printed circuit board 42.

At this time, the printed board 42 is
Although not shown, two connectors are provided, and the connector pins 219 of the tuners 21 and 22 are provided to these connectors.
229 is plugged in, so that the tuners 21, 22
Are connected to the printed circuit board 42.

According to this structure, the printed circuit board 2
Since the ground planes 21B and 22B of 11, 212 act as a shield, even if unnecessary radiation is emitted from one of the tuners 21 and 22 toward the other, it is attenuated by the ground planes 21B and 22B and the tuner 21 and the tuner 22 are separated from each other. Mutual interference due to unwanted radiation between them is reduced. Therefore, tuner 2
1 and the tuner 22 can be arranged close to each other, and at this time, the bit error rate of the TS output from the tuners 21 and 22 is not deteriorated and the performance is not deteriorated.

Further, as shown in FIG. 2, the tuner 2
It is only necessary to provide the shield plates 212 and 222 on the parts 1 and 22, and as is apparent from comparison with FIG. 5, the number of shield members can be reduced. Further, since it is not necessary to dispose the tuner 21 and the tuner 22 on the main board 42 with sufficient separation, the distance between the two connectors 218 and 219 does not become wider than necessary, and the design of the receiving device 20 is impaired. Nor.

Further, since the printed boards 210 and 220 can have the same outer shape with respect to the tuner 21 and the designs of the printed boards 210 and 220 are plane-symmetrical, the additional cost and additional design of the board die can be achieved. The man-hour of will not occur. Also, the two tuners 21,
Not only can the isolation between 22 be easily secured, but also two systems of TS outputs with uniform characteristics can be obtained.

In the above description, the tuners 21 and 22
However, they may receive different digital satellite broadcasts. Also, the method of using the TS output from the tuners 21 and 22 is arbitrary, and it can be used not only for recording the back program but also for picture-in-picture.

[List of Abbreviations Used in This Specification] D / A: Digital to Analog HDD: Hard Disk Drive MPEG: Motion Picture Image Coding Experts Grou
p TS: Transport Stream

[0028]

According to the present invention, since the costly shield member can be reduced, the cost of the receiving device can be suppressed. In addition, mutual interference between tuners can be reduced, so that performance is not deteriorated. Further, since it is not necessary to dispose the two tuners sufficiently apart from each other, the design of the receiving device is not damaged. Further, the additional cost of the substrate mold of the printed circuit board of the tuner and the additional man-hours for the design do not occur. In addition, 2 with uniform characteristics
The TS output of the system can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing one form of a tuner that can be used in the present invention.

FIG. 2 is a partial cross-sectional plan view showing one embodiment of the present invention.

FIG. 3 is a system diagram showing one form of a receiving apparatus to which the present invention can be applied.

FIG. 4 is a plan view for explaining the present invention.

FIG. 5 is a plan view, part of which is a cross section, for explaining the present invention.

[Explanation of symbols]

21 and 22 ... Tuner, 21A and 22A ... Component mounting surface, 21B and 22B ... Ground plane, 41 ... Rear panel, 42 ... Printed circuit board, 210 and 220 ... Double-sided printed circuit board, 211 and 221 ... Component, 212 and 222 ... Shield Members 218 and 228 ... Antenna input connector

Claims (4)

[Claims] 1. At least first and second tuners, wherein the first and second tuners each have a double-sided printed circuit board and a predetermined component, and the double-sided printed circuit board has one surface thereof. The mounting surface of the component is provided, and almost the entire surface of the other surface is a ground surface, and the mounting surface of the first double-sided printed circuit board and the second surface
In the receiving device, the mounting surface of the double-sided printed circuit board is plane-symmetrical, and the first and second double-sided printed circuit boards are arranged inside so that the ground planes face each other. 2. The receiving device according to claim 1, wherein the first and second double-sided printed circuit boards are respectively provided with antenna input connectors, and the antenna input connectors project from the rear panel. A receiving device in which first and second double-sided printed circuit boards are arranged. 3. The receiving device according to claim 2, wherein the first and second tuners are tuners for receiving digital satellite broadcasts, respectively. 4. The receiving device according to claim 3, wherein the receiving device has a device for storing and reproducing the program of the digital satellite broadcasting.