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GB2156162A - Casing for housing an oscillator circuit of an RF modulator - Google Patents

Casing for housing an oscillator circuit of an RF modulator Download PDF

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Publication number
GB2156162A
GB2156162A GB08428673A GB8428673A GB2156162A GB 2156162 A GB2156162 A GB 2156162A GB 08428673 A GB08428673 A GB 08428673A GB 8428673 A GB8428673 A GB 8428673A GB 2156162 A GB2156162 A GB 2156162A
Authority
GB
United Kingdom
Prior art keywords
oscillation circuit
substrate
frequency devices
casing
compartment
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB08428673A
Other versions
GB8428673D0 (en
GB2156162B (en
Inventor
Shigeru Nigorikawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alps Alpine Co Ltd
Original Assignee
Alps Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Alps Electric Co Ltd filed Critical Alps Electric Co Ltd
Publication of GB8428673D0 publication Critical patent/GB8428673D0/en
Publication of GB2156162A publication Critical patent/GB2156162A/en
Application granted granted Critical
Publication of GB2156162B publication Critical patent/GB2156162B/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05KPRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00Screening of apparatus or components against electric or magnetic fields
    • H05K9/0007Casings
    • H05K9/006Casings specially adapted for signal processing applications, e.g. CATV, tuner, antennas amplifier

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
  • Noise Elimination (AREA)

Abstract

A casing for an oscillator of an RF modulator is provided with a compartment (4') for the oscillation circuit and a compartment (5') for the high frequency circuits. A printed circuit board (35) has a substrate (35b) for the oscillation circuit and a substrate (35a) for the high- frequency devices, which substrates are formed integrally with each other. The printed circuit board (35) is accommodated by the casing such that the substrate (35b) for the oscillation circuit and the substrate (35a) for the high-frequency devices are received by the compartments (4', 5'), respectively. <IMAGE>

Description

SPECIFICATION Construction for housing oscillation circuit of RF modulator BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a construction for housing the oscillation circuit of an RF modulatorfor use in devices such as a VTR.
Description ofthe Prior Art In recent years, there is a trend for compact VTRs, particularly in the case of portable VTRs. This gives a rise to the demand for reduction in sizes of parts which are incorporated in portableVTRs. One of such parts is an RF modulator.
Forthereasonswhichwill be explained later in the connection with the attached drawings, hitherto, there has been a practical limit in the reduction of size of the construction for encasing the oscillation circuit of the RF modulator. In addition, the assmbling of the RF modulator in a small casing required a high level of skill in locating various parts.
SUMMARY OF THE INVENTION Objectofthe Invention: Accordingly, an object of the invention is to provide a construction for encasing the oscillation circuit of an RF modulator, improved to reduce the number of parts thereby allowing an easy assembling without high degree of skill and reduction in the thickness of the casing.
Brief Summary of the Invention: To this end, according to the invention, there is provided a constructionforencasing an oscillator of an RF modulator having a casing provided with a compartmentforthe oscillation circuit and a compartmentfor other circuits, the compartment for oscil lation circuitaccommodating the oscillation circuit while the compartment for other other circuits accommodating other circuits, comprising: a printed board having a substrate for oscillation circuit and a substrate for high-frequency devices, the substrates being integral with each other, the substrate for oscillation circuit carrying electronic parts ofthe oscillation circuitwhilethe substrate for high-frequency devices carries electronic parts for high-frequency devices; and a communicating portion formed in the casing for providing a communicating between the compart mentforoscillation circuit and the compartmentfor other circuits; whereby the printed board is accommodated by the casing such that the substrate for oscillation circuit and the substrate for high-frequency devices are received by the compartments for oscillation circuit and the high-frequency devices, respectively, such that the portion ofthe printed board between the substrate is received by the communication portion.
The above and other objects,features and advantages of the invention will become clearfrom the following description ofthe preferred embodiments taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a partly-sectioned side elevational view of an RF modulator having a conventional construction for encasing the oscillation circuit: Fig. 2 is a plan view of an RF modulator shown in Fig.
1 with the upper and lower covers thereof removed; Fig. 3 is an exploded perspective view of an RF modulatorshown in Fig. 1; Fig. 4 is a partly-sectioned side elevational view of an RF modulator having the construction in accordance with the invention for encasing the oscillation circuit; Fig. 5 is a plan view of the RF modulator shown in Fig. 4with the upper and lower covers thereof removed; Fig. 6 is an exploded perspective view of the RF modulator shown in Fig. 4; and Fig. 7 is an enlarged perspective view of the mounting frame as shown in Fig. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT Before describing the embodiment of the invention, an explanation will be made hereinunderastothe conventional construction with specific reference to Figs. to 3, in orderto facilitate the understanding of the invention.
Referring to Fig. 1, a casing of a conventional RF modulator has a mounting frame 1 and an upper cover 2 and a lower cover 3which are attached to the mounting frame 1. The mounting frame 1 is formed by bending and shaping a blank punched out from a sheet material. The mounting frame 1 has a compart ment4forencasing an oscillation circuit and a compartment for encasing other circuits, as shown in Figs. 2 and 3.
The oscillating circuit encasing compartment 4 has a substantially U-shaped cross-section constituted by a bottom wall 4a and side walls 4b, 4c connected thereto. As will be seen from Fig. 3, the sidewalls 4b, 4c are provided with holes 6 and 7 for supporting a rotorshaft,aswellasspring-retaining holes 8 and 9.
Spring retaining notches 10 and 11 are formed in the end wall 4d which closes one end of the oscillation circuit encasing compartment 4.
The oscillation circuit encasing compartment4 encases an oscillation circuit which includes a variable capacitor 12, electronic parts 14 mounted on an oscillation circuit substrate 13, a connector plate 15 constituting an oscillator line, a pickup 16 and other parts. The pickup 16 is connected to terminals 17 and 18 extending through the side wall 4c. The variable capacitor 12 is constituted by a rotor 1 2a and a stator 12b.The rotor 1 2a is carried by a rotor shaft 1 2which is supported in the supporting holes 6 and 7, while the stator 1 2b is brazed to the bottom wall 4a. The rotor shaft 12c is urged towards the bottom wall by linear springs 19 and 20 which are retained, respectively, by the retaining hole 8 and the retaining notch 10 and by the retaining hole 9 and the notch 11.
The com partment 5 for encasing other circuits accommodates a substrate 21 for high-frequency devices. The substrate 21 carries electronic parts 22 constituting the circuits for the high-frequency devices. In Figs. 1 to 3, a reference numeral 23 denotes a connector attached to the substrate 21 for high frequency device, while 24 denotes a pin-type connector attached to the mounting frame 1. The electronic parts 22 shown in Fig. 2 are omitted from Fig. 3.
Thus, in the conventional RF modulator, the subs trate i3fortheoscillationcircuitandthesubstrate2l for high-frequency devices are prepared separately, and are encased by separate compartments: namely, the compartment4forthe oscillation circuitand the compartment for other circuits. Consequently, the conventional RF modulator has a large number of parts.
On the other hand, the assembling of the conventional RF modulator requires specific jigs for positioning the parts such as the the variable capacitor 12, oscillation circuit substrate 13 and other parts in relation to each other. Therefore, a high degree of skill and experience are required for positioning there parts by using such jigs. The substrate 13 for the oscillation circuit is fixed to the bottom wall 4a to extend upwardly therefrom to a level somewhat higherthan thevariable capacitor 12. This constitutes a bottle neck in the reduction ofthethickness of the case.
These problems encountered bythe prior art, however, are overcome by the present invention as will be explained hereinunder.
A preferred embodiment of the invention will be explained i ereinunder with reference to Figs. 4 to 7 in which the same reference numberals are used to denote the same or equivalent parts as those in the conventional RF modulator explained before, and description of such same or equivalent parts is omitted.
Referring first to Fig. 4, the modulator has a casing which is constituted by a mounting frame 25, an upper cover2and a lower cover 3. The uppercover2andthe lower cover3 are fitted to the upper and lower sides of the mounting frame 25.
The mounting frame 25 has side walls 26,27,28 and 29, as well as an upperwall 30. The sidewall 26 is formed along one side edge 30a ofthe upperwall 30 integrally therewith. The upper ends of the side walls 27,28 are integrally connected to the longitudinal edges 30b, 30c of the upperwall 30, while the side wall 29 is formed on the other end of the sidewall 28 integrallytherewith, as will be seen from Fig. 5.
Namely, the side walls 26,27 and 28 are formed by bending the same sheet material as the upperwall 30 downwardly substantially at a right angle along the edges30a,30band30c,whilethesidewall 29 is formed by bending the samesheet asthesidewall 28 substantiallyata right angle along the other edge of the side wall 28. Thus, the mounting frame 25 having the described construction can be formed by pun chingasheetblankfromasheetmaterial and bending the blank in a manner explained hereinabove.
Ashield wall 31 serving as a partition wall isformed to depend downwardlyata rightanglefrom a half part of the other edge 30d of the upperwall 30. Substrate positioning legs 32,32 are formed to extend downwardlyfrom the lower end of the shield wall 31. (see Figs. 6 and 7) In addition, a bottom wall 33 serving as a wall for mounting parts is formed so asto extend in parallel with the upper wall 30 from the lower end ofthe side wall 26 adjacer.tto the side wall 28. Furthermore, an attaching wall 34 integral with the bottom wall 33 extends upwardly from the portion ofthe bottom wall 33 adjacentto the shield wall towards the upper wall 30.
In this mounting frame 25, a compartment4' for encasing the oscillation circuit is defined by the side wall 26, one end of the sidewalls 27,28, upperwall 30 and the shield wall 31, while a compartment 5'for encasing other circuit is defined by the side walls 27, 28,29 and the shield wall 31.The compartment4'for oscillation circuit is divided by the attaching wall 34 into a space Afor accommodating the variable capacitorand a space B for accommodating the printed circuit board.On the other hand, a wiring space C is formed between the attaching wall 34 and the side wall 26, while a communicating portion D is formed atthe lower side oftheshieldwall 31 so as to provide a communicating between the compartment 4' for accommodating the oscillation circuit and the compartment 5' for accommodating other circuits.
A printed circuit board 35 has an L-like form constituted by a substrate 35a for the high-frequency devices and a substrate 35b for oscillation circuit.
Electronic parts 22 for the high-frequency devices are mounted on the upper side of the substrate 35a for the high-frequency devices, while electronic parts 14 of the oscillation circuit are attached to the lower side of the substrate 35b for the oscillation circuit. Locating holes36,36 in the form of angular apertures are formed in the portion ofthe printed board 35 between the substrate 35a forthe high-frequency devices and the substrate 35b for the oscillation circuit. Electronic parts 14,22shown in Figs. 4and 5 are omitted from Fig. 6.
The substrate 35a ofthe printed board 35 for high-frequency devices is disposed in the compartment 5' for other circuits, while the substrate 35b for the oscillation circuit is accommodated by the space B in the compartment 4' for receiving the oscillation circuit past the communicating portion D. (see Fig. 4 and 5) In this state, the substrate locating legs 32,32 on the shield wall 31 are received by the locating holes36,36 in the printed board 35. The electronic parts 14are shielded by a shield cover 37 attached to the lower side of the substrate 35b forthe oscillation circuit.
A reference numeral 38 designates a variable capacitor block constituted by a variable capacitor 12 and a stationary plate 39. The rotor 12a and the stator 1 2b of the variable capacitor 12 are assembled togetherandthe rotor 12a is rotatably heid by the stationary plate 39 while the stator 12b is fixed to the stationary plate 39. This variable capacitor block 37 is disposed in the space a and the stationary plate 39 is fixed by brazing to the bottom wall 33, side wall 28 and the attaching wall 34. An operation hole 40 facing the operating end of the rotor shaft 12c is formed in the sidewall 26 ofthe mounting frame 25. In the drawings, a reference numberal 41 designates an operation groove provided on the operation end ofthe rotor shaft 12c.
An explanation will be made hereinunderastothe function of the described construction for encasing the oscillation circuit of the RF modulator.
For attaching the printed board 35 to the mounting frame 25, the printed board 35 is first disposed such that the substrate 35a for high-frequency devices confronts the lower end of the compartment 5' for other circuits while the substrate 35bforthe oscilla tion circuit confronts the lower end of the oscillation compartment 4' forthe oscillation circuit.Then, the printed board 35 is inserted into the mounting frame 25throughthe lower open end ofthe mounting frame 25 such that the substrate locating legs 32, 32 on the shield wall 31 are received by corresponding locating holes 36,36 in the printed board 35, until the substrate 35a forthe high-frequency devices and the substrate 35b forthe oscillation circuit are received by the compartments 5' and 4', respectively. The electronic parts 14,22 are attached beforehand to the printed board 35, and the parts 14 are shielded bythe shield cover in advance.
Then, the variable capacitor block 38 is disposed in the space A and the stationary plate 39 is fixed by brazing tothe bottom wall 33, side wall 28 and the attaching wall 34, so that the variable capacitor 12 which has been assembled in the form of a unit is situated in the predetermined portion of the space A with the operation end of the rotor shaft 12c thereof confronting the operation hole 40.
After mounting the parts in the mounting frame 25, the upper and lower covers 2 and 3 are fitted to the upperand Iowersidesofthemountingframe25,thus completing the mounting ofthe parts on the mounting frame 25.
As has been described, the invention provides a construction for encasing an oscillator of an RF modulator having a casing provided with a compartmentforthe oscillation circuit and a compartment for other circuits, the compartment for oscillation circuit accommodating the oscillation circuit while the compartmentfor other circuits accommodating other circuits, comprising: a printed board having a substrate for oscillation circuit and a substrate for high frequency devices, the substrates being integral with each other, the substrate for oscillation circuit carrying electronic parts ofthe oscillation circuitwhile the substrate for high-frequency devices carries electro nic partsfor high-frequency devices; and a communicating portion formed in the casing for providing a communicating between the compartment for oscil lation circuit and the compartment for other circuits; whereby the printed board is accommodated by the casing ng such that the substrate for oscillation circuit and the substrate for high-frequency devices are received by the compartments for oscillation circuit and the high-frequency devices, respectively, such thatthe portion of the printed board between the substrate is received by the communicating portion.
According to the invention, therefore, it is possible toreducethe number of parts and to eliminatethe necessityforany high degree of skill and experience for locating parts, while allowing a reduction ofthe thickness ofthe casing as compared with the conventional arrangement.
Although the invention has been described through specific terms, it isto be noted here that the described embodiment is not exclusive and various changes and modifications may be imparted thereto without departing from the scope of the invention which is limited solely by the appended claims.

Claims (3)

1. A construction for encasing an oscillator of an RF modulator having a casing provided with a compartment tor the oscillation circuit and a compartmentforothercircuits,saidcompartmentforoscillation circuit accommodating said oscillation circuit while the compartment for other circuits accommodating other circuits, comprising: a printed board having a substrate for oscillation circuit and a substrate for high-frequency devices, said substrates being integral with each other, said substratefor oscillation circuit carrying electronic parts of said oscillation circuit while the substrate for high-frequency devices carries electronic parts for high-frequency devices; and a communicating portion formed in said casing for providing a communicating between said compartmentfor oscillation circuit and said compartment forothercircuits; whereby said printed board is accommodated by said casing such that the substrate foroscillationcircuitandthesubstrateforhigh- frequency devices are received by said compartments for oscillation circuit and said high-frequency devices, respectively, such that the portion of said printed board between said substrate is received by said communicating portion.
2. A housing for an oscillatorsubstantially as hereinbefore described, with reference to Figures 4-7 ofthe accompanying drawings.
3. An oscillator including a housing according to claim 1 orto claim 2.
GB08428673A 1984-03-16 1984-11-13 Rf modulators Expired GB2156162B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3678784U JPS60150809U (en) 1984-03-16 1984-03-16 RF modulator oscillation circuit storage structure

Publications (3)

Publication Number Publication Date
GB8428673D0 GB8428673D0 (en) 1984-12-19
GB2156162A true GB2156162A (en) 1985-10-02
GB2156162B GB2156162B (en) 1988-08-10

Family

ID=12479489

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08428673A Expired GB2156162B (en) 1984-03-16 1984-11-13 Rf modulators

Country Status (2)

Country Link
JP (1) JPS60150809U (en)
GB (1) GB2156162B (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4816612A (en) * 1986-10-08 1989-03-28 Goldstar Co., Ltd. Shield case for antenna terminal
GB2222487A (en) * 1988-09-06 1990-03-07 Plessey Telecomm A cabinet for electronic equipment
US5162610A (en) * 1990-03-21 1992-11-10 Control Systems, Inc. Shielded enclosure for an electronic device
WO1994006268A1 (en) * 1992-08-28 1994-03-17 Thomson Consumer Electronics, Inc. Printed circuit board shield assembly
US5414597A (en) * 1994-05-04 1995-05-09 Ford Motor Company Shielded circuit module
GB2285181A (en) * 1993-12-23 1995-06-28 Hitec Sheet Metal Limited Electromagnetic radiation shielding for printed circuit boards
GB2297868A (en) * 1995-02-07 1996-08-14 Nokia Mobile Phones Ltd EMI/RFI shielding device
GB2319898A (en) * 1996-12-02 1998-06-03 Alps Electric Co Ltd A shielding case
EP1122992A1 (en) * 2000-02-03 2001-08-08 Telefonaktiebolaget Lm Ericsson Method and apparatus for providing EMI-sealing between a cabinet opening and a closure means for closing said opening
US6992901B1 (en) * 2005-03-18 2006-01-31 Inventec Appliances Corp. Shielding device for an electronic apparatus

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2019102A (en) * 1978-03-13 1979-10-24 Mitsumi Electric Co Ltd High-frequency circuit device
GB2029645A (en) * 1978-08-07 1980-03-19 Mitsumi Electric Co Ltd High-frequency circuit device
GB2101811A (en) * 1981-06-30 1983-01-19 Racal Dana Instr Ltd Improvements in and relating to the screening of electrical circuit arrangements

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2019102A (en) * 1978-03-13 1979-10-24 Mitsumi Electric Co Ltd High-frequency circuit device
GB2029645A (en) * 1978-08-07 1980-03-19 Mitsumi Electric Co Ltd High-frequency circuit device
GB2101811A (en) * 1981-06-30 1983-01-19 Racal Dana Instr Ltd Improvements in and relating to the screening of electrical circuit arrangements

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4816612A (en) * 1986-10-08 1989-03-28 Goldstar Co., Ltd. Shield case for antenna terminal
GB2222487A (en) * 1988-09-06 1990-03-07 Plessey Telecomm A cabinet for electronic equipment
US5162610A (en) * 1990-03-21 1992-11-10 Control Systems, Inc. Shielded enclosure for an electronic device
US5644101A (en) * 1992-08-28 1997-07-01 Thomson Consumer Electronics, Inc. Printed circuit board shield assembly
WO1994006268A1 (en) * 1992-08-28 1994-03-17 Thomson Consumer Electronics, Inc. Printed circuit board shield assembly
GB2285181A (en) * 1993-12-23 1995-06-28 Hitec Sheet Metal Limited Electromagnetic radiation shielding for printed circuit boards
US5414597A (en) * 1994-05-04 1995-05-09 Ford Motor Company Shielded circuit module
GB2297868A (en) * 1995-02-07 1996-08-14 Nokia Mobile Phones Ltd EMI/RFI shielding device
US5895884A (en) * 1995-02-07 1999-04-20 Nokia Mobile Phones, Ltd. Shielding device with push fit lid
GB2297868B (en) * 1995-02-07 1999-04-28 Nokia Mobile Phones Ltd A shielding device
GB2319898A (en) * 1996-12-02 1998-06-03 Alps Electric Co Ltd A shielding case
GB2319898B (en) * 1996-12-02 2001-02-28 Alps Electric Co Ltd Shielding case
EP1122992A1 (en) * 2000-02-03 2001-08-08 Telefonaktiebolaget Lm Ericsson Method and apparatus for providing EMI-sealing between a cabinet opening and a closure means for closing said opening
WO2001058232A1 (en) * 2000-02-03 2001-08-09 Telefonaktiebolaget Lm Ericsson Method and apparatus for providing emi-sealing between a cabinet opening and a closure means for closing said opening
US6992901B1 (en) * 2005-03-18 2006-01-31 Inventec Appliances Corp. Shielding device for an electronic apparatus

Also Published As

Publication number Publication date
GB8428673D0 (en) 1984-12-19
JPS60150809U (en) 1985-10-07
GB2156162B (en) 1988-08-10

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PCNP Patent ceased through non-payment of renewal fee