JP2008278099A - Television tuner device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a television tuner device capable of receiving terrestrial analog, digital broadcasting, and satellite broadcasting, to reduce any influence to be given from a noise to be emitted from a certain integrated circuit to components connected to another circuit, and to reduce the influence of heat generation between integrated circuits. <P>SOLUTION: The substrate surface and back face of a multi-layer substrate 5 are divided into four sections M1 to M4 by a shield board 6, and a tuner IC1 for terrestrial analog and digital broadcasting reception, a tuner IC2 for satellite digital broadcasting reception, an IC 3 for digital broadcasting signal demodulation, and an IC 4 for analog broadcast signal demodulation are loaded with such layout that they are not affected by their mutual heat radiation. Furthermore, a hollow core coil 11c which is mostly affected by any noise signal to be radiated from the IC3 for digital broadcast signal demodulation is loaded on the substrate back side at the opposite side of the substrate surface on which the IC3 for digital broadcast signal demodulation is loaded, and at least the surrounding of the hollow core coil 11c is surrounded by the shield board 6 so as to be sealed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a television tuner apparatus capable of receiving terrestrial analog / digital broadcasting and satellite digital broadcasting.

  In recent years, television tuners that can receive terrestrial analog and digital broadcasts as well as satellite digital broadcasts have appeared. On the other hand, for the purpose of downsizing the television tuner, etc., a high-frequency unit that processes the television signal of the high-frequency signal received by the antenna, and a demodulation unit that demodulates the television signal output from the high-frequency unit, Television tuners each composed of an integrated circuit have been developed. In the case of a television tuner capable of receiving terrestrial analog / digital broadcasts and satellite digital broadcasts, a total of four integrated circuits including a terrestrial broadcast reception tuner IC, a satellite digital broadcast reception tuner IC, a digital demodulation IC, and an analog demodulation IC. Will be installed.

By the way, in a television tuner, a noise signal radiated from a digital demodulator may adversely affect other components, particularly reception components (for example, air core coils). For this reason, in Patent Document 1, a shield layer is formed on the inner layer of a multilayer substrate on which a tuner circuit and a digital circuit are mounted in one system of television tuner, and the tuner circuit and the digital circuit are divided into a front surface and a back surface of the substrate. This arrangement reduces the influence of noise signals radiated from the digital circuit.
JP 2002-135669 A

  However, in the case of a television tuner capable of receiving terrestrial analog / digital broadcasts and satellite digital broadcasts, there are a total of four integrated circuits as described above. Therefore, as described in Patent Document 1, two integrated circuits (a tuner circuit and a digital circuit) are provided. It is not sufficient to arrange the circuit) separately on the front surface and the back surface of the substrate, and the arrangement of the remaining two integrated circuits becomes a problem. If three integrated circuits are mounted on the substrate surface opposite to the surface on which the digital circuit is arranged, a large mounting area is required and it is difficult to reduce the size. Further, since the integrated circuit generates heat, it becomes a problem how to release the heat radiation of each integrated circuit in a limited space.

  The present invention has been made in view of this point, and can reduce the influence of noise radiated from one integrated circuit on components connected to another circuit, and the influence of heat generation between integrated circuits is small. An object of the present invention is to provide a television tuner device capable of maintaining component performance.

  The television tuner device of the present invention includes a terrestrial broadcast receiving input terminal to which a terrestrial broadcast signal is input, a satellite broadcast receiving input terminal to which a satellite broadcast signal is input, and a terrestrial broadcast signal from the terrestrial broadcast receiving input terminal. A first terrestrial broadcast receiving tuner that performs frequency conversion and program selection, and a satellite broadcast reception tuner that receives a satellite broadcast signal from the satellite broadcast reception input terminal and performs frequency conversion and program selection. A second integrated circuit constituting the third integrated circuit; a third integrated circuit constituting a digital demodulating circuit for demodulating a terrestrial / satellite digital broadcast signal output from the first and second integrated circuits; and the first integrated circuit. And a fourth integrated circuit constituting an analog demodulation circuit for demodulating a terrestrial analog broadcast signal output from the substrate, and a predetermined pattern is formed on the substrate surface and the substrate back surface. A circuit board on which the first to fourth integrated circuits and other circuit components are mounted on a pattern, and the circuit board is divided into four sections each having one integrated circuit mounted thereon, An area in contact with the broadcast receiving input terminal is in contact with the first area, an area in contact with the satellite broadcast receiving input terminal is in the second area, and the second area is in contact with the second area on the side opposite to the satellite broadcast receiving input terminal. A zone is a third zone, a zone that is in contact with the first zone on the opposite side of the input terminal for receiving terrestrial broadcasting is a fourth zone, and the first integration is performed on the substrate surface side of the first zone. A circuit is mounted, the second integrated circuit is mounted on the back side of the substrate in the second area, the third integrated circuit is mounted on the substrate surface side of the third area, and the fourth area is mounted. The fourth integrated circuit is mounted on the back side of the substrate. It is characterized in.

  According to this configuration, the circuit board is divided into four sections, and the first integrated circuit constituting the terrestrial broadcast receiving tuner is mounted on the first section in contact with the terrestrial broadcast receiving input terminal on the board surface side. Since the third integrated circuit constituting the digital demodulator circuit is mounted in the third area and the other integrated circuits are mounted in the corresponding area on the back side of the substrate, the four integrated circuits are affected by the heat radiation of each other. Since a space can be secured on the back surface of the substrate in the first area, RF components installed in the front stage of the tuner for receiving terrestrial broadcasts are easily affected by noise from the digital demodulation circuit in the first area. It can be arranged on the back side of the substrate, and the influence of noise from the digital demodulation circuit can be reduced.

  According to the present invention, in the above-described television tuner device, an air-core coil that is a part of an RF circuit component disposed in the preceding stage of the first integrated circuit is mounted on the back side of the substrate in the first area. It is characterized by.

  With this configuration, the air-core coil that is susceptible to noise from the digital demodulation circuit among the RF circuit components is disposed on the back side of the substrate in the first area, so that the influence of noise from the digital demodulation circuit can be reduced. .

  In the television tuner device according to the present invention, a shield plate that shields the substrate rear surface side of the first area on which the air-core coil is mounted from other areas at high frequency is provided.

  With this configuration, the air-core coil, which is a receiving component of the RF circuit, is shielded at high frequencies from other areas, so that the influence from the integrated circuit or parts installed on the back side of the substrate in the other areas is reduced. Can do.

  In the television tuner device according to the present invention, the circuit board is formed of a multilayer substrate in which a plurality of insulating layers are stacked, and the substrate surface side and the substrate back surface are provided by a grounding conductor layer provided in an inner layer of the multilayer substrate. The side is shielded.

  With this configuration, the ground surface conductor layer provided on the inner layer of the multilayer substrate shields the substrate surface side and the substrate back surface side, so that the noise signal radiated from the digital demodulation circuit mounted on the substrate surface side is transmitted to the substrate back surface side. It is possible to prevent wraparound and to reduce the influence on the second integrated circuit and the RF circuit component constituting the satellite broadcast receiving tuner mounted on the back side of the substrate.

  According to the present invention, it is possible to receive terrestrial analog / digital broadcasts and satellite digital broadcasts, it is possible to reduce the influence of noise radiated from one integrated circuit on components connected to other circuits, and between integrated circuits. It is possible to realize a television tuner that can maintain the component performance with little influence of heat generation.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic plan view of a television tuner according to an embodiment of the present invention. The television tuner according to the present embodiment is a television tuner capable of receiving terrestrial analog / digital broadcasting and satellite digital broadcasting, and includes four integrated circuits. In the present embodiment, a terrestrial analog / digital broadcast receiving tuner IC1 serving as a first integrated circuit, a satellite digital broadcast receiving tuner IC2 serving as a second integrated circuit, and a digital broadcast signal serving as a third integrated circuit. A total of four integrated circuits including a demodulation IC 3 and an analog broadcast signal demodulation IC 4 serving as a fourth integrated circuit are mounted.

  The first to fourth integrated circuits 1 to 4 are mounted on the front surface and the back surface of the multilayer substrate 5 in an arrangement that is not affected by mutual heat dissipation. The multilayer substrate 5 has a rectangular shape as a whole, and the front and back surfaces are divided into four sections M1 to M4 by a shield plate 6 having a predetermined height.

  In the first area M1 at the upper left in FIG. 1, a terrestrial analog / digital broadcast receiving tuner IC1, an RF circuit component 11, and a grounding terminal 12 dedicated to the area are installed on the substrate surface M1a. A terrestrial broadcast receiving input terminal 13 is provided on the side of the first section M1. The terrestrial broadcast receiving input terminal 13 is electrically connected to the RF circuit component 11 through a line or pattern formed on the multilayer substrate 5.

  In the second area M2 at the lower left in FIG. 1, a satellite digital broadcast receiving tuner IC2 is disposed on the back surface M2b of the substrate. A satellite digital broadcast receiving input terminal 14 is connected to the side of the second section M2. The satellite broadcast receiving input terminal 14 is electrically connected to the satellite digital broadcast receiving tuner IC 2 through a line or pattern formed on the multilayer substrate 5 and an RF circuit component (not shown). No integrated circuit is arranged on the substrate surface M2a in the second area M2.

  In the third area M3 at the lower right in FIG. 1, the digital broadcast signal demodulation IC 3 is disposed on the substrate surface M3a. The third section M3 is adjacent to the right side of the second section M2 (opposite side of the input terminal 14) and is in a diagonal positional relationship with the first section M1. No integrated circuit is disposed on the substrate back surface M3b in the third area M3.

  In the fourth area M4 on the upper right in FIG. 1, an analog broadcast signal demodulation IC 4 is disposed on the back surface M4b of the substrate. The fourth area M4 is adjacent to the right side of the first area M1 (opposite the input terminal 13) and is in a diagonal relationship with the second area M2. No integrated circuit is arranged on the substrate surface M4a in the fourth area M4.

  FIG. 2 is a schematic diagram showing the structure of the multilayer substrate 5, and is a schematic cross-sectional view of the terrestrial analog / digital broadcast receiving tuner IC 1 and the analog broadcast signal demodulating IC 4 in FIG. is there. The multilayer substrate 5 includes an insulating layer 5a that forms the front surface side, an insulating layer 5b that forms the back surface side, and a grounding conductor layer 5c that is formed between the insulating layers 5a and 5b and functions as a shield layer. . The present invention is not limited to the multilayer substrate 5 having a two-layer structure, and a multilayer substrate having three or more layers can also be used.

  A pattern 21 is formed on the substrate surface M1a in the first area M1. A terrestrial analog / digital broadcast receiving tuner IC 1 and a part 11 b of the RF circuit component 11 are mounted on the pattern 21. In addition, a receiving component that is particularly affected by a noise signal radiated from the digital broadcast signal demodulation IC 3, which is another IC, is disposed on the substrate rear surface M 1 b in the first section M 1. In this example, an air-core coil 11c constituting the inductor component of the tuning circuit is arranged in the RF circuit. The air-core coil 11c is inserted into the through hole 7 formed in the multilayer substrate 5 from the substrate back surface M1b and is conducted to the pattern 21.

  A pattern 22 is formed on the back surface M4b of the substrate in the fourth area M4, and a terminal of the analog broadcast signal demodulation IC 4 is connected to the pattern 22. Patterns are formed on the substrate front surfaces M2a and M3a and the substrate back surfaces M2b and M3b of other areas M2 and M3 as necessary, and the terminals of the satellite digital broadcast receiving tuner IC2 and the digital broadcast signal demodulating IC3 are connected. ing.

  3A is a schematic perspective view of the television tuner according to the present embodiment as viewed from the front side of the substrate, and FIG. 3B is a schematic perspective view of the television tuner as viewed from the back side of the substrate. As shown in FIG. 3A, the substrate surface of the multilayer substrate 5 is divided from the center to the left and right by the shield plates 6a and 6b, and the substrate surface is divided from the center to the top and bottom by the shield plates 6c and 6d. It has been. Further, the outer periphery of the substrate surface is surrounded by shield plates 6e to 6h. As a result, the substrate surface M1a in the first section M1 where the tuner IC1 for receiving terrestrial analog / digital broadcasts and the RF circuit component 11 are arranged has a shield structure surrounded by the shield plates 6a, 6c, 6e, 6h. . The substrate surface M3a of the third section M3 formed on the substrate surface in a diagonal position with respect to the substrate surface M1a of the first section M1 and where the digital broadcast signal demodulating IC 3 is disposed is shield plates 6b, 6d, 6f, 6g. The shield structure is surrounded by.

  Further, as shown in FIG. 3B, the back surface of the multilayer substrate 5 is divided from the center to the right and left by the shield plates 6aa and 6bb, and the back surface of the substrate is vertically moved from the center by the shield plates 6cc and 6dd. It is divided into. The outer periphery of the back surface of the substrate is surrounded by shield plates 6ee to 6hh. As a result, the substrate back surface M1b of the first section M1 where the air-core coil 11c, which is a part of the RF circuit component 11 of the terrestrial analog / digital broadcast receiving tuner IC1, is disposed is the shield plates 6aa, 6cc, 6ee, 6hh. The shield structure is surrounded. Further, the satellite digital broadcast receiving tuner IC and the RF circuit component (not shown) arranged on the back surface M2b of the second area M2 have a shield structure surrounded by shield plates 6bb, 6cc, 6hh, 6gg, The analog broadcast signal demodulation IC 4 arranged on the substrate back surface M4b of the fourth section M4 has a shield structure in which the periphery is surrounded by shield plates 6bb, 6dd, 6ff, and 6gg. In this example, the shield structure is such that all areas are surrounded by a shield plate. However, the air-core coil 11c mounted on the substrate back surface M1b in the first area M1 is particularly susceptible to noise, so at least this area only. May be surrounded by shield plates 6aa, 6cc, 6ee, 6hh.

  As described above, the terrestrial analog / digital broadcast receiving tuner IC1 is arranged on the substrate surface M1a of the first section M1 at the diagonal position on the substrate surface side of the multilayer substrate 5, and the substrate surface of the third section M3. An IC 3 for demodulating a digital broadcast signal is disposed in M3a, and an integrated circuit is provided on the substrate surface M2a of the second area M2 adjacent to the first area M1 or the third area M3 and the substrate surface M4a of the fourth area M4. Was not placed. On the substrate surface side of the multilayer substrate 5, integrated circuits and circuit components that may be affected by noise signals emitted by the digital broadcast signal demodulation IC 3 disposed on the substrate surface M3a of the third section M3 are terrestrial analog / digital. The broadcast receiving tuner IC1 and the RF circuit component 11 are shielded by the shield plates 6a, 6c, 6e, and 6h as described above.

  Here, the flow of the reception signal in the television tuner will be described. A terrestrial analog / digital broadcast wave is received by an antenna (not shown), and a television signal is input to the terrestrial broadcast receiving input terminal 13. For example, a terrestrial analog broadcast television signal is extracted by an RF circuit, frequency-converted and selected by a terrestrial analog / digital broadcast receiving tuner IC 1, output to an analog demodulation IC 4, and demodulated video and audio signals are output. Sent out. The television signal of terrestrial digital broadcasting is taken out by the RF circuit, frequency-converted and selected by the terrestrial analog / digital broadcast receiving tuner IC 1, output to the digital demodulation IC 3, and the demodulated video signal and audio signal are output. Sent out. On the other hand, a satellite digital broadcast wave is received by an antenna (not shown), and a satellite television signal is input to the satellite broadcast reception input terminal 14. The satellite digital broadcast television signal is taken out by the RF circuit, frequency-converted and selected by the satellite digital broadcast receiver tuner IC, output to the digital demodulation IC 4, and demodulated video and audio signals are sent to the outside. The

  According to the present embodiment configured as described above, the surroundings of the terrestrial analog / digital broadcast receiving tuner IC1 and the RF circuit component 11 are shielded in high frequency by the shield plates 6a, 6c, 6e, 6h. The influence of the noise signal radiated from the broadcast signal demodulation IC 3 can be reduced. Further, since the periphery of the digital broadcast signal demodulation IC 3 is surrounded by further shield plates 6b, 6d, 6f and 6g, the influence of the noise signal radiated by the digital broadcast signal demodulation IC 3 can be further reduced. In addition, in this example, the RF circuit component 11 that is susceptible to the noise radiated from the digital broadcast signal demodulation IC 3 (in this example, the air-core coil 11 c) is arranged on the back side of the multilayer substrate 5. Since the grounding conductor layer 5c is formed on the inner layer of the multilayer substrate 5, the influence of the noise signal radiated by the digital broadcast signal demodulation IC 3 on the air-core coil 11c with the grounding conductor layer 5c functioning as a shield layer is not affected. It can be reduced to an extent that there is almost no problem. Further, the first section M1 is provided with a dedicated grounding terminal 12 that is separated in high frequency from the grounding conductors (grounding conductor layer 5c) of the other sections M2 to M4. Thereby, it is possible to eliminate the influence from the other integrated circuits (2, 4) including the IC 3 for demodulating the digital broadcast signal.

  Further, according to the present embodiment, the multilayer substrate 5 is divided into four areas M1 to M4, and the integrated circuit is arranged only on one of the substrate front surface and the substrate back surface in the same area. Can be arranged without being affected by mutual heat dissipation.

  The present invention can be applied to a television tuner apparatus equipped with four integrated circuits corresponding to terrestrial analog / digital broadcasting and satellite digital broadcasting.

1 is a schematic plan view of a television tuner according to an embodiment of the present invention. The schematic diagram which shows the cross-section of the multilayer substrate in the said one Embodiment (A) The typical perspective view which looked at the television tuner concerning the said embodiment from the board | substrate surface side, (b) The typical perspective view which looked at the television tuner from the board | substrate back surface side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Terrestrial analog digital broadcast reception tuner IC, 2 ... Satellite digital broadcast reception tuner IC, 3 ... Digital broadcast signal demodulation IC, 4 ... Analog broadcast signal demodulation IC, 5 ... Multi-layer substrate, 5a, 5b ... Insulation Layers, 5c: grounding conductor layer, 6: shield plate (whole), 6a-6h ... shield plate (substrate front side), 6aa-6hh ... shield plate (substrate back side), 7 ... through hole, 11 ... RF circuit 11c ... Air-core coil, 12 ... grounding terminal, 13 ... terrestrial broadcast receiving input terminal, 14 ... satellite broadcasting receiving input terminal, 21, 22 ... pattern, M1 ... first area, M2 ... second Area, M3 ... third area, M4 ... fourth area, M1a to M4a ... substrate surface, M1b to M4b ... substrate back surface

Claims (4)

A terrestrial broadcast receiving input terminal to which a terrestrial broadcast signal is input;
An input terminal for satellite broadcast reception to which satellite broadcast signals are input;
A first integrated circuit that constitutes a terrestrial broadcast reception tuner that takes in a terrestrial broadcast signal from the terrestrial broadcast reception input terminal and performs frequency conversion and program selection;
A second integrated circuit that constitutes a satellite broadcast receiving tuner that takes in a satellite broadcast signal from the satellite broadcast reception input terminal and performs frequency conversion and program selection;
A third integrated circuit constituting a digital demodulating circuit for demodulating terrestrial / satellite digital broadcast signals output from the first and second integrated circuits;
A fourth integrated circuit constituting an analog demodulation circuit for demodulating a terrestrial analog broadcast signal output from the first integrated circuit;
A circuit board on which a predetermined pattern is formed on the front surface and the back surface of the substrate, and the first to fourth integrated circuits and other circuit components are mounted on the pattern,
The circuit board is divided into four areas each mounting one integrated circuit, the area in contact with the terrestrial broadcast receiving input terminal is the first area, and the area in contact with the satellite broadcast receiving input terminal is the second area. A third area, an area in contact with the second area on the opposite side to the satellite broadcast receiving input terminal, and a third area, an area in contact with the first area on the opposite side to the terrestrial broadcast receiving input terminal Is the fourth area,
Mounting the first integrated circuit on the substrate surface side of the first area;
Mounting the second integrated circuit on the back side of the substrate in the second area;
Mounting the third integrated circuit on the substrate surface side of the third section;
A television tuner apparatus, wherein the fourth integrated circuit is mounted on the back side of the substrate in the fourth area.   2. The television tuner according to claim 1, wherein an air-core coil that is a part of an RF circuit component disposed in front of the first integrated circuit is mounted on the back side of the substrate in the first area. apparatus.   3. The television tuner apparatus according to claim 2, further comprising a shield plate that shields the back side of the first area on which the air-core coil is mounted from other areas at high frequency. The circuit board is constituted by a multilayer substrate in which a plurality of insulating layers are laminated, and the substrate surface side and the substrate back side are shielded by a grounding conductor layer provided in an inner layer of the multilayer substrate. The television tuner device according to any one of claims 1 to 3.

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