JPH05102865A - Card type electronic tuner - Google Patents

Abstract

PURPOSE:To obtain the external electronic tuner capable of receiving by attaching it to a main body only when it is desired to receive television video and audio in an equipment such as a personal computer or an 8mm video without always necessitating the tuner. CONSTITUTION:A printed circuit board 6 constituting a tuner circuit part 9, channel control circuit part and demodulation circuit part 11 is built in a card type case 2, and connectors to input/output signals to the printed circuit board 6 are arranged along one side of the case 2. The case 2 is composed of a frame 3, upper cover 4 and lower cover 5, and the upper cover 4 is double-constructed like composed of an inner cover part 4a and an outer cover part 4b. Then, holes 45a-45d for adjustment are provided at the inner cover part 4a. Therefore, the components of the tuner circuit part are adjusted in the state of attaching the inner cover part and afterwards, the outer cover part can be attached.

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.

The case described above includes a frame that surrounds the circuit board, an upper cover that closes the upper opening of the frame and forms a predetermined space from the circuit board, and a lower cover that closes the lower opening of the frame. Equipped with. In addition, at least a portion of the upper cover that faces the region forming the tuner circuit portion on the circuit board has a double structure.

[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, since at least the portion of the upper cover facing the region of the tuner circuit portion has a double structure,
Even if a hole for adjustment is provided in the inner cover part of this upper cover,
This hole can be covered by the outer cover part.

[0012]

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 enables signal input / output 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, since at least the portion of the upper cover that faces the region of the tuner circuit portion has a double structure, parts such as coils forming the tuner circuit portion are adjusted in the inner cover portion of this double structure. Even if you provide a hole for
This hole can eventually be covered by the outer cover part. Therefore, it is possible to provide a preferable structure in terms of appearance and dust resistance. It is also possible to adjust the tuner circuit section with the inner cover section covering the tuner circuit section, and then attach the outer cover section, making adjustments with the upper cover open. It is possible to prevent the adjustment deviation from occurring due to electromagnetic interference caused by the upper cover when the upper cover is mounted. Even if a large adjustment hole is provided in the inner cover part, it will be covered by the outer cover part in the end, so that the adjustment work can be performed easily and the tolerance for misalignment of the parts to be adjusted is achieved. Can also be larger.

[0015]

1 is a perspective view showing the appearance of a card type electronic tuner 1 according to an embodiment of the present invention. Figure 2
FIG. 2 is an enlarged sectional view taken along the line II-II in FIG. 1. Figure 3
FIG. 2 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. Case 2 is frame 3, frame 3
And an upper cover 4 for closing the upper opening of the frame 3, and a lower cover 5 for closing the lower opening of the frame 3. Such a case 2 is preferably sized substantially the same as a general-purpose IC memory card.

The frame 3 is formed of a molded product made of a synthetic resin having an increased rigidity such as glass fiber reinforced polyphenylene sulfide, polyethylene terephthalate and polycarbonate. Such a frame 3 may be subjected to metal plating, conductive coating, or the like at a necessary portion for the purpose of improving the shield property.

The upper cover 4 and the lower cover 5 are preferably 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 7a to 7j, ... And a connector 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, for example, ceramic, or may have a multilayer structure. Further, each outer surface of the lower cover 5 and the upper cover 4 can be appropriately used as a surface 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 7a to 7j, ... And the connector 8 are mounted is surrounded by the frame 3 in the case 2, and is mainly positioned by the frame 3. The upper cover 4 and the lower cover 5 are fixed to the frame 3 by screwing, for example.
It is performed by a method such as adhesion or welding.

Various circuits are formed on the printed circuit board 6 as represented by the electronic components 7a to 7j shown in FIG. The circuit constructed on this printed circuit board 6 is shown in FIG.

Referring to FIG. 3, 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.
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 respectively shown in FIG.
The first area 40 and the second area 4 sectioned by the broken line in FIG.
It is arranged in the first and third regions 42. First area 40
VHF circuit section 12 included in the tuner circuit section 9
The positional relationship between the UHF circuit unit 13 and the UHF circuit unit 13 can be arbitrarily changed. In the case 2, a shield plate (described later) that separates the tuner circuit unit 9, the channel control circuit unit 10, and the demodulation circuit unit 11 from each other is arranged. Such a shield plate includes an upper cover 4 and a lower cover 5,
In addition, it is electrically connected to an earth land on the printed circuit board 6 so that the overall shield performance is ensured.

A shield plate 43, which is one of the shield plates described above, is shown in FIG. This shield plate 43 is
The frame 3 is attached along a partition wall 44 provided so as to cross the main surface of the printed circuit board 6.

Referring again to FIG. 2, the upper cover 4 has a double structure including an inner cover portion 4a and an outer cover portion 4b. Inner cover portion 4a and outer cover portion 4b
Are both made of a metal plate, and the outer cover portion 4b is preferably made to have a rigidity equal to or higher than that of the inner cover portion 4a.

In the cross section shown in FIG. 2, the first region 40 (FIG. 1) forming the tuner circuit portion 9 (FIG. 3) and the demodulation circuit portion 11 (FIG. 3) in the printed circuit board 6 are formed. Region 3 of FIG. 3 (FIG. 1) is visible. Of the components that make up the tuner circuit section 9, a component 7a that requires adjustment
Adjustment holes 45a to 45d are provided in the inner cover portion 4a corresponding to the positions 7d to 7d. In addition, among the components of the demodulation circuit unit 11, the relatively tall component 7
A relief hole 46 is provided in the inner cover portion 4a corresponding to the position e. Thus, by providing the escape hole 46, it is possible to prevent the thickness of the case 2 from increasing due to the presence of the tall component 7e.

FIG. 4 is a sectional view corresponding to FIG. 2, showing a card type electronic tuner 1a according to another embodiment of the present invention. Note that, in FIG. 4, the elements corresponding to the elements shown in FIG. 2 are denoted by the same reference numerals, and overlapping description will be omitted.

In the embodiment shown in FIG. 4, the upper cover 4 has a double structure only in the portion of the printed circuit board 6 facing the region 40 (FIG. 1) constituting the tuner circuit portion 9. Is characterized by. That is, the upper cover 4
Has a double structure of an inner cover portion 4a and an outer cover portion 4b, but the inner cover portion 4a extends only at a portion facing the tuner circuit portion 9.

In this embodiment, the components 7a to 7d and the like included in the tuner circuit section 9 are low-profile components mainly composed of transistors, capacitors, resistors, coils, diodes, etc., and constitute the demodulation circuit section 11. The components 7e to 7j and the like are made paying attention to that they include many high-profile components such as tantalum capacitors, ceramic filters, helical coils, ICs, and variable resistors. According to this embodiment, it is not necessary to provide the escape hole 46 in the inner cover portion 4a as in the above-described embodiments, and the upper cover 4 is not provided.
It is possible to reduce the weight as compared with the case where all of them have a double structure.

FIG. 5 is a sectional view showing a part of a card type electronic tuner 1b according to still another embodiment of the present invention. Note that, in FIG. 5, elements corresponding to the elements shown in FIG. 2 are denoted by the same reference numerals, and redundant description will be omitted.

The embodiment shown in FIG. 5 has an inner cover portion 4a.
A characteristic is that a part of the shield plate is bent to form the shield plate 47. The shield plate 47 is, for example, the electronic component 7
It can be formed by a metal plate that is removed to form a relief hole 46 for e. Shield plate 47
Includes a contact piece 48 that penetrates the printed circuit board 6 and contacts the lower cover 5, and a contact piece 50 that contacts an earth land 49 on the printed circuit board 6.

Although not provided in the illustrated embodiment, the receiving antenna may be externally attached or built in such a card type electronic tuner.

[Brief description of drawings]

FIG. 1 is a perspective view showing an external appearance of a card type electronic tuner 1 according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along the line II-II in FIG.

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

FIG. 4 is a sectional view corresponding to FIG. 2, showing a card type electronic tuner 1a according to another embodiment of the present invention.

FIG. 5 is a sectional view showing a part of a card type electronic tuner 1b according to still another embodiment of the present invention.

[Explanation of symbols]

 1, 1a, 1b Card type electronic tuner 2 Case 3 Frame 4 Upper cover 4a Inner cover part 4b Outer cover part 5 Lower cover 6 Printed circuit board 7a to 7j Electronic parts 8 Connector 9 Tuner circuit part 10 Channel control circuit part 11 Demodulation circuit Part 12 VHF circuit part 13 UHF circuit part 45a to 45d adjustment hole 46 escape hole 47 shield plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazunori Kinoshita 2-10-10 Tenjin, Nagaokakyo, Kyoto Prefecture Murata Manufacturing Co., Ltd.

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, the case includes a frame surrounding the circuit board, an upper cover that closes an upper surface opening of the frame and forms a predetermined space between the case and the circuit board, And a lower cover that closes an opening on the lower surface of the frame, wherein at least a portion of the upper cover facing a region forming a tuner circuit portion on the circuit board has a double structure.