JPH05122012A - Card type electronic tuner - Google Patents

Abstract

PURPOSE:To provide an externally mounted electronic tuner capable of receiving by being mounted on a main body only when the video and sound of TV are to be received in an equipment such as a personal computer or an 8mm video unnecessitating tuners normally. CONSTITUTION:Within a card type case main body 3, a print circuit board 6 composing a tuner circuit part 9, a channel control circuit part 10 and a demodulation circuit part 11 is positioned, and a connector 8 performing the input/output of a signal for the print circuit board 6 is arranged along a side of the case main body 3. Shield members 43, 44 are mounted on the print circuit board 6, respectively, relating to areas 40, 41 composing the tuner circuit part 9 and the channel control circuit part 10. The case main body 3 has a top panel wall 4a and a side surface wall 4b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic tuner, and more particularly to improving the form of such an electronic tuner.

[0002]

2. Description of the Related Art Television receivers require a tuner, and as such a tuner, an electronic tuner has been widely used recently. Electronic tuners often include tuner circuitry and channel control circuitry for selectively tuning both UHF and VHF signals.

Such an electronic tuner is built in the main body of the television receiver.

[0004]

As a device having an image display function which is generally used at present, in addition to the above-mentioned television receiver, for example, a personal computer having a display, such as a so-called 8 mm video device. , Information equipment, etc. As a matter of course,
Since a tuner is not built in these video equipment or information equipment, it is not possible to receive a television broadcast and output its video and audio.

However, in many cases, these video equipment and information equipment already have sufficient functions to be used as a television receiver as long as they have a tuner. Therefore, if these video equipment or information equipment can be used as a television receiver as necessary, the applications of these equipment can be expanded, and as a result, the commercial value can be increased. it can.

Therefore, the present invention seeks to meet the above-mentioned needs by improving the structure of an electronic tuner.

[0007]

In order to solve the above-mentioned technical problems, the present invention provides a card type electronic tuner.

This card type electronic tuner has a card type case, a circuit board housed in the case, and a tuner circuit section, a channel control circuit section and a demodulation circuit section which are formed in different regions, and the circuit board. And a connector arranged along one side of the case.

Further, a shield member is mounted on the circuit board to cover at least a region where the tuner circuit section is formed, and the case has a top wall and a side wall for positioning and covering the circuit board. It has a main body.

[0010]

According to the present invention, the circuits necessary for the electronic tuner, including the peripheral circuits necessary for reception, are housed in the card type case, and the input / output of signals can be performed via the connector. ..

Further, the shield member serves to shield at least the tuner circuit section from other circuit sections and the outside.

Further, as described above, since the shield member is provided, the case is not particularly required to have a shield action, and therefore the case may be molded of resin, for that reason. The case body having the top wall and the side wall can be made of resin.

[0013]

Therefore, according to the present invention, an electronic tuner of card type as a whole, such as an IC memory card, can be obtained. Such a card-type electronic tuner is easy to store and carry, and is suitable for handling as an optional accessory for various video equipment or information equipment. Therefore, it is not necessary to store a function that is not always used in the main body of these devices, such as a function as a television receiver in a video device or an information device. It can be prevented.

Further, the card type electronic tuner according to the present invention is provided with all circuits necessary for the tuner including peripheral circuits necessary for reception, and the input / output of signals can be performed through the connector. Therefore, they can be made to function as a television receiver by mounting them on the main body of the video equipment or the information equipment when necessary. In this case, the main body of the video equipment or the information equipment is provided with, for example, a slot in which the card type electronic tuner can be mounted, and a connector paired with the connector provided in the card type electronic tuner is associated with this slot. It should be provided. If such a slot can be shared with other function cards, it becomes easy to give a plurality of optional functions to one device by switching with a switch, for example.

Further, the above-mentioned shield member can block unnecessary electromagnetic interference between at least the tuner circuit section and other circuit sections as well as external noise, so that the card-type electronic tuner is concerned. The overall performance can be stabilized.

Further, the shield member is mounted on the circuit board by soldering or the like, like other electronic parts.
The shield member can be handled together with the circuit board. Therefore, the efficiency of the assembling work of the card type electronic tuner can be improved.

If the shield member is provided with a hole for adjusting the tuner circuit portion, the tuner circuit portion can be adjusted with the shield member mounted on the circuit board. For example, if the tuner circuit section is adjusted before the shield member is attached, then when the shield member is attached, the adjustment deviation may occur due to electromagnetic interference by the shield member. In addition, if you adjust after installing the shield member,
It is possible to prevent such an adjustment deviation. This also means that the quality of the circuit board can be determined before it is assembled into the case. Therefore, it is possible to assemble the card-type electronic tuner by using only the good circuit board, which is a waste of manufacturing work. Can be eliminated.

Further, since the case is provided with the case body having the top wall and the side wall, it is possible to increase the rigidity of the case which is thin and therefore tends to lack rigidity. Further, since the shield member is mounted on the circuit board, the case is not particularly required to have a shielding property. Therefore, the case body can be made of resin without any problem, and thus the case body can be easily obtained.

[0019]

FIG. 1 is an exploded perspective view of elements constituting a card type electronic tuner 1 according to an embodiment of the present invention. FIG. 2 is a perspective view showing the external appearance of the card type electronic tuner 1 obtained by the elements shown in FIG.
FIG. 3 is an enlarged sectional view taken along the line III-III in FIG. FIG. 4 is a block diagram showing an electric circuit provided in the card type electronic tuner 1.

The card type electronic tuner 1 includes a card type case 2. The case 2 includes a case body 3 and a lower cover 5. Such case 2 is preferably
It has substantially the same dimensions as a general-purpose IC memory card.

The case body 3 has a top wall 4a and a side wall 4b, and is made of, for example, glass fiber reinforced polyphenylene sulfide, polyethylene terephthalate,
It is composed of a molded product made of a synthetic resin having an increased rigidity such as polycarbonate. Such a case body 3 may be subjected to metal plating, conductive coating, or the like at a necessary portion for the purpose of improving the shielding property.

The lower cover 5 is made of a conductive material such as a metal plate in order to exhibit a shielding property.

A circuit board is housed in the case 2. The circuit board comprises a printed circuit board 6 in this example. On the printed circuit board 6, for example,
A double-sided wiring type of glass epoxy substrate having a thickness of 0.5 mm is used. Required electronic components 7 and connectors 8 are surface-mounted on the upper surface of the printed circuit board 6. The lower surface of the printed circuit board 6 is provided with required wiring and ground wiring which are electrically connected to the wiring on the upper surface through the through holes. Although not shown, the lower surface of the printed circuit board 6 is covered with an insulating film.

The printed circuit board 6 may be made of a material such as ceramic, or may have a multilayer structure. Further, the outer surfaces of the case body 3 and the lower cover 5 can be appropriately used as surfaces for printing or the like.

As described above, the connector 8 surface-mounted on the printed circuit board 6 is of a socket type and is arranged along the short side of the case 2, for example.

The printed circuit board 6 on which the required electronic components 7 and the connector 8 are mounted is positioned in the case 2 mainly by the case body 3. Lower cover 5
Is fixed to the case main body 3 by, for example, a method such as screwing, adhesion, or welding.

As represented by the electronic component 7 shown in FIGS. 1 and 3, various circuits are formed on the printed circuit board 6. The circuit constructed on this printed circuit board 6 is shown in FIG.

Referring to FIG. 4, the circuit formed on the printed circuit board 6 is roughly divided into a tuner circuit section 9, a channel control circuit section 10 and a demodulation circuit section 11.
Further, the tuner circuit unit 9 includes the VHF circuit unit 12 and the U
The HF circuit unit 13 is provided.

U input from the U / V signal input terminal 14
The HF / VHF signal is distributed by the distributor 15 and input to the corresponding circuit unit 12 or 13. These circuit units 12 and 13 are respectively provided with a bandpass filter 16
And 17, amplifiers 18 and 19, and bandpass filters 20 and 21.

The channel control circuit section 10 includes a channel control circuit 22, and the output of the channel control circuit 22 is input to local oscillation circuits 23 and 24. The local oscillation signal output from one local oscillation circuit 24 is mixed with the high frequency signal output from the bandpass filter 21 of the UHF circuit unit 13 in the mixing circuit 25, and then amplified in the mixing / amplifying circuit 26. It On the other hand,
The local oscillation signal output from the local oscillation circuit 23 is mixed in the mixing / amplification circuit 26 with the high frequency signal output from the bandpass filter 20 of the VHF circuit unit 12.

The intermediate frequency signal output from the mixing / amplifying circuit 26 is input to the amplifier 28 provided in the demodulation circuit section 11 through the bandpass filter 27. The signal amplified by the amplifier 28 is input to the demodulation circuit 30 via the surface acoustic wave filter 29. In the demodulation circuit 30, the video signal is AM-detected and the audio signal is FM-detected to be demodulated into a video signal and an audio signal, which are applied to the video signal output terminal 31 and the audio signal output terminal 32, respectively. From the demodulation circuit 30,
A sync signal is applied to the sync signal output terminal 33.

Further, on the above-mentioned printed circuit board 6, a power supply voltage terminal 34 for supplying a power supply voltage to the entire circuit formed thereon, and the channel control circuit section 10 are provided.
A tuning voltage terminal 35 for supplying a tuning voltage to the channel control circuit section 10,
A clock terminal 36 for supplying a data signal and an enable signal, a data terminal 37 and an enable terminal 35, and a ground terminal 39 are formed.

The terminals 14, 31 to 39 thus formed on the printed circuit board 6 are electrically connected to the corresponding contacts provided on the connector 8.

The tuner circuit section 9, the channel control circuit section 10, and the demodulation circuit section 11 described above are arranged in the first area 40, the second area 41, and the third area 42 on the printed circuit board 6, respectively. It The positional relationship between the VHF circuit unit 12 and the UHF circuit unit 13 included in the tuner circuit unit 9 in the first region 40 can be arbitrarily changed.

A box-shaped shield member 43 is mounted on the printed circuit board 6 so as to cover the first region 40, that is, the region where the tuner circuit portion 9 is formed. In addition, the second region 41, that is, the channel control circuit unit 1
Another shield member 44 is mounted on the printed circuit board 6 so as to surround the area where 0 is formed. These shield members 43 and 44 are fixed to the printed circuit board 6 by the solder 45, like the other electronic components 7. At this time, the shield members 43 and 44 are connected to the solder 4
It is electrically connected to a ground land (not shown) on the printed circuit board 6 via 5. In order to position the shield members 43 and 44 with respect to the printed circuit board 6, the printed circuit board 6 may be provided with a slot or the like for receiving a part of each of the shield members 43 and 44.

A shield member 43 for covering the tuner circuit section 9
Comprises a top wall 46 and side walls 47 extending vertically from the periphery of the top wall 46. The top wall 46 is provided with a plurality of adjustment holes 48. Below these adjusting holes 48, the electronic component 7 to be adjusted is located (see FIG. 3). The side wall 47 acts to shield the tuner circuit portion 9 from the other circuit portions 10 and 11 and the outside.

The shield member 44 provided so as to surround the channel control circuit unit 10 is mainly composed of a side wall 49, and a relatively narrow upper wall 50 is provided with a contact piece 51 extending downward. Be done. Although not shown, the contact piece 51 penetrates the ground land on the printed circuit board 6 and / or the printed circuit board 6 and contacts the lower cover 5.

In this embodiment, the shield members 43 and 44 are provided in association with the tuner circuit unit 9 and the channel control circuit unit 10, respectively, but further, the shield members are provided in association with the demodulation circuit unit 11. May be.
Further, such a shield member is particularly required only in the circuit portion that is easily affected by external noise, and therefore, only the shield member 43 is provided and the shield member 4 is provided.
4 may be omitted. Further, with respect to the shield member 43, the side wall 47 is provided so as to surround the tuner circuit portion 9 over the entire circumference. May be done.

In FIG. 1, the lower surface of the case body 3 is shown by a broken line. Further, in FIG. 3, the case main body 3 is shown in cross section. As can be seen from FIGS. 1 and 3, the thickness of the case body 3 is different depending on the location in the portion of the printed circuit board 6 that faces the circuit portions 9, 10, and 11. This is an electronic component 7 mounted on the printed circuit board 6 as well as the shield member 4.
The thickness of the case main body 3 is made thick so as not to interfere with 3 and 44, and the rigidity of the case main body 3 is increased. Therefore, some steps and ribs can be seen on the lower surface of the case body 3. The step provided on the upper surface wall 46 of the shield member 43 and the step provided on the side wall 49 of the shield member 44 are also based on consideration for making the wall thickness of the case body 3 as thick as possible.

Although the lower cover 5 is used in the above-mentioned embodiment, it may be omitted if the lower surface of the printed circuit board 6 can be formed almost entirely on the ground surface.

Although not provided in the illustrated embodiment,
The receiving antenna is attached to such a card type electronic tuner,
It may be external or internal.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing elements included in a card type electronic tuner 1 according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an external appearance of the card type electronic tuner 1 shown in FIG.

3 is an enlarged sectional view taken along line III-III in FIG.

4 is a block diagram showing an electric circuit formed on the printed circuit board 6 shown in FIGS. 1 and 3. FIG.

[Explanation of symbols]

 1 Card Type Electronic Tuner 2 Case 3 Case Body 4a Top Wall 4b Side Wall 6 Printed Circuit Board 7 Electronic Components 8 Connector 9 Tuner Circuit Section 10 Channel Control Circuit Section 11 Demodulation Circuit Section 12 VHF Circuit Section 13 UHF Circuit Section 43,44 Shield Member 45 Solder 48 Adjustment hole

Claims (1)

[Claims] 1. A card-type case; a circuit board housed in the case and having a tuner circuit section, a channel control circuit section, and a demodulation circuit section in separate regions; and electrically connected to the circuit board. And one of the above cases
A connector arranged along one side, a shield member is mounted on the circuit board, the shield member covering at least a region where the tuner circuit portion is configured, and the case positions and covers the circuit board. A card type electronic tuner including a case body having a top wall and a side wall.