JP2007314026A - On-vehicle electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide on-vehicle electronic equipment capable of effectively preventing an adverse effect of noise generated from a drive unit part on an electronic circuit substrate as well as attempting dust protection against a drive unit in simple constitution. <P>SOLUTION: A main substrate 12 and a DVD drive device 14 are vertically provided in a case body 12, and a dust protective cover 22 made of metal plate is provided to cover an upper surface part of the DVD drive device 14. A contact piece part to elastically make surface-contact with an inner bottom surface of a lower case 14 is integrally provided on the dust protective cover 22, and a contact point part 24 protruded upward and electrically connected to a ground pattern of the main substrate 13 is integrally provided by drawing. The contact point part 24 is screwed and connected to the main substrate 13. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an in-vehicle electronic device incorporated in a vehicle, such as a car navigation device or a car audio device.

  For example, as a vehicle-mounted electronic device incorporated in a vehicle such as an automobile, there is a main body (navigator ECU) of a car navigation device. As shown in FIG. 6, the main body 1 of the navigation device includes a main board 3 on which a control circuit (microcomputer) for controlling the whole, a power supply circuit, and the like are mounted on the upper and lower portions in a metal housing 2, and a map. And a DVD drive device 4 for reading a DVD storing data and the like. The DVD drive device 4 and the main board 3 are connected by a connection cable 5. Further, a connector 6 for connection to the outside (display unit, various sensors, antennas, etc.) is attached to the rear side of the main substrate 3, and this connector 6 is an opening on the back side of the housing 2. It is exposed facing 2a.

  At this time, since the DVD drive device 4 uses a precision optical device for the data reading unit, there is a situation in which entry of dust or the like must be avoided in order to ensure good reading performance. However, since the main body 1 is mounted under the passenger seat of the passenger compartment, for example, dust that has fluttered from the carpet, as indicated by an arrow A in the figure, etc. There is a risk of intrusion from the inside. Therefore, conventionally, a plastic dustproof cover 7 that covers the DVD drive device 4 is provided in the housing 2 to prevent dust from entering the DVD drive device 4 as much as possible. .

Incidentally, in the drive unit such as the DVD drive device 4, as another problem, the internal data reading unit becomes a source of electrical noise, and the electrical noise affects the main board 3 (for example, reception of GPS signals). There was a great risk of performance deterioration. Conventionally, in a pickup that optically reproduces an optical disk such as a CD, it has been considered to provide a box-shaped electrostatic shield case or a magnetic shield case so as to cover the entire pickup to shield noise (for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-296899

  However, as described above, simply covering the drive unit with the shield case is not necessarily sufficient in terms of preventing adverse effects due to electrical noise on the main board 3. In this case, strengthening the grounding in the main board 3 is effective as a measure for preventing the adverse effects due to electrical noise.

  As a specific means for that purpose, as shown in FIG. 6, it is conceivable to electrically connect the GND pattern of the main board 3 and the housing 2 functioning as a stable ground by a contact spring 8. However, in this method, since it is necessary to add the contact spring 8, there is a problem that the number of parts increases, the assembling workability deteriorates, and the cost increases.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to incorporate a drive unit and an electronic circuit board in a housing, and can protect the drive unit from dust, and from the drive unit portion. An object of the present invention is to provide an in-vehicle electronic device that can effectively prevent a generated noise from adversely affecting an electronic circuit board with a simple configuration.

  In order to achieve the above object, an in-vehicle electronic device of the present invention includes a drive unit that reads data from a storage medium and an electronic circuit board in a metal casing, and a dustproof cover that covers the drive unit. The dust-proof cover has electrical conductivity, and the contact portion electrically connected to the ground pattern of the electronic circuit board is connected to the dust-proof cover and the housing. It has the characteristic in the structure which provided the contact part which contacts a body integrally (invention of Claim 1).

  According to the present invention, since conductivity is imparted to the dust cover that covers the drive unit, it is possible to obtain a shielding effect for electrical noise generated in the drive unit in addition to the dust prevention effect for the drive unit. In addition to this, the ground pattern of the electronic circuit board is electrically connected (grounded) to the housing functioning as a stable ground through the dust cover, so that the grounding of the electronic circuit board can be strengthened. It is possible to effectively prevent the influence of electrical noise. And since the contact part and the contact part are integrally provided in the dust-proof cover, it can be completed with a simple configuration without increasing the number of parts.

  More specifically, the dustproof cover can be made of a metal plate, and the contact portion can be integrally formed by drawing (invention of claim 2). According to this, the whole dustproof cover can be comprised from one metal plate, and it can be completed with a comparatively cheap and simple structure. Since the contact portion is formed by drawing, the material is continuous, so that there is no dust intrusion or noise leakage from this portion.

  In the present invention, the contact portion of the dust cover may be connected to the electronic circuit board by screwing (Invention of Claim 3). According to this, since the contact portion of the dustproof cover and the electronic circuit board are fixed, the electrical connection between the contact portion and the ground pattern can be more reliably performed.

  Further, the contact portion of the dustproof cover may be formed in a plate shape that is in surface contact with the inner surface of the housing, and may be configured to elastically contact the inner surface of the housing due to its own springiness. Invention). Thereby, the contact part of a dust-proof cover can be made to contact the inner surface of a housing | casing stably, and an electrical connection can be performed reliably. In addition, the assembly process and the number of parts can be increased.

  An embodiment in which the present invention is applied to a main body (navigator ECU) of a car navigation apparatus will be described below with reference to FIGS. 1 to 3 show an overall configuration of a main body (navigator ECU) 11 of a car navigation device that is an in-vehicle electronic device according to the present embodiment. As shown in FIG. 5, the main body 11 is configured by incorporating a main board 13 that is an electronic circuit board and a DVD drive device 14 that is a drive unit in a metal housing 12. The main body 11 is mounted on, for example, the lower part of the passenger seat in the passenger compartment.

  The casing 12 as a whole has a slightly thin rectangular box shape. Specifically, as shown in FIG. 2 and the like, the casing 12 is configured by combining an upper case 15, a lower case 16, and a rear bracket 17. Among them, the upper case 15 has a rectangular lid shape having a falling portion around a rectangular plate, and mounting portions 15a protruding downward are integrally provided at the four corners of the lower surface thereof. The lower case 16 has a rectangular container shape with the front portion and the left and right side portions rising upward, and the rear bracket 17 is provided on the rear portion of the lower case 16, and the lower rear half portion of the housing 12. Is configured. As shown in FIG. 4, a plurality of engaging claws 17 a that engage with the upper case 15 and the lower case 16 with spring properties are integrally provided on the upper and lower sides of the rear bracket 17.

  The lower case 16 and the upper case 15 are joined from below the lower case 16 by tightening a screw into a screw hole of the mounting portion 15a through a screw insertion hole. The rear bracket 17 is engaged with the upper case 15 and the lower case 16 by the engaging claw portion 17a, and the lower surface portions of the left and right end portions are fastened together with the lower case 16, thereby forming the housing 12. At this time, as shown in FIG. 1, an opening in which a plurality of connectors 18 mounted on the main board 13 are disposed between the upper case 15 and the rear bracket 17 on the rear surface of the housing 12. A portion 12a is provided. A slight gap is formed between the connector 18 and the opening 12a.

  As shown in FIGS. 1 to 3, a design escutcheon 19 is provided from the front surface portion of the housing 12 to the front upper surface portion as necessary. As shown in FIGS. 2 and 3, the front surface of the escutcheon 19 is provided with a disk (DVD) entrance 19a and a switch 19b for taking out the disk. In the present embodiment, the upper case 15 is made of, for example, a casting, and the lower case 16 and the rear bracket 17 are configured by processing a metal plate (for example, a thin iron plate). The escutcheon 19 can be made of plastic.

  The DVD drive device 14 is for reading map data, a program, and the like from a storage medium such as a DVD (not shown), and is disposed on the lower side (lower case 16) in the housing 12. As is well known, the DVD drive device 14 includes a disk drive mechanism, a reading mechanism having an optical head using a laser, a control device, and the like in a thin rectangular case. As shown in FIG. 2, a horizontally long disk insertion opening 14a is provided on the front surface of the case. Also, as shown in FIG. 1, a flat surface for connecting to the main board 13 is provided from the side of the case. A connection cable 20 is led out.

  The DVD drive device 14 has a mounting front bracket 21 (shown only in FIG. 2) attached to the front thereof, and is accommodated in the lower case 16 and mounted by screwing or the like. At this time, although not shown, an entrance / exit corresponding to the disc insertion port 14a is also provided on the front surface portion of the lower case 16 so that the entrance / exit portion is covered with a dustproof cover having a cut. It has become. Of course, the entrance / exit of the lower case 16 corresponds to (overlaps) the entrance / exit 19a provided in the escutcheon 19.

  The main board 13 is mounted with various circuits such as a control circuit (microcomputer) for controlling the whole and a power supply circuit, and a plurality of connectors 18 are mounted on the rear side as described above. . The control circuit performs various navigation processes such as own vehicle position calculation, display control of the display device, map drawing, route search, route guidance, and search by the software configuration. The main board 13 is attached to the upper case 15 by screwing or the like, and is arranged on the upper side in the housing 12. Although not shown, a ground pattern is provided on the back surface (lower surface) side of the main substrate 13.

  Although detailed illustration and description are omitted, the connector 18 is connected to a display unit having a color liquid crystal display device and switches, an in-vehicle LAN to which various in-vehicle sensors and the like are connected, a GPS antenna, and the like. ing. Further, the connection cable 20 is connected to the main board 13, and the map data read by the DVD drive device 14 is transferred.

  In the housing 12, a dust cover 22 is provided so as to cover the DVD drive device 14 in order to prevent dust from entering the reading unit of the DVD drive device 14. In this embodiment, the dustproof cover 22 is formed by processing a thin metal plate (for example, an iron plate) such as cutting, bending, drawing, and the like, and thus has conductivity. Hereinafter, the dust cover 22 will be described in detail with reference to FIGS.

  That is, as shown in FIGS. 2 and 4, the dust-proof cover 22 has falling portions 22b and 22b bent substantially at a right angle downward on both left and right sides of the main portion 22a having a rectangular plate shape. Furthermore, the contact pieces 23 and 23 as contact portions are integrally provided so as to be bent substantially perpendicularly in the horizontal direction (left and right outer sides) from the lower ends of the falling portions 22b and 22b. The main part 22a of the dust cover 22 is arranged so as to cover the upper part of the DVD drive device 14 and to divide it vertically from the main board 13. At this time, as shown in FIG. 23 is placed on the inner bottom surface of the housing 12 (lower case 16).

  Accordingly, the contact piece portions 23 and 23 are plate-like in surface contact with the inner surface of the housing 12. In this case, the contact piece portions 23 and 23 are elastically formed by the spring properties of the falling portions 22 b and 22 b and the contact piece portions 23 and 23. It comes to contact. Further, as shown in FIGS. 2 and 5, the dust cover 22 integrally has an insertion piece portion 22 c that rises substantially perpendicularly upward from the front side portion of the main portion 22 a. As shown in FIG. 5, the insertion piece 22 c is inserted into an insertion groove 15 b composed of a plurality of ribs integrally provided on the inner surface of the upper case 15, and thus the front portion of the dust-proof cover 22. The side positioning is fixed.

  The main portion 22 a of the dustproof cover 22 is integrally provided with a contact portion 24 that protrudes upward and is electrically connected to the ground pattern on the lower surface of the main substrate 13. In this case, as shown in FIG. 2, FIG. 4, etc., the contact portion 24 is integrally provided by drawing the dustproof cover 22 (main portion 22a), and the rear side portion of the main portion 22a. It is located at two positions on the left and right sides, and is formed in a relatively flat truncated cone shape.

  Furthermore, in this embodiment, a screw insertion hole 24a (see FIG. 4) is formed in the center of the upper surface of each contact portion 24. Although not shown in detail, the main board 13 is provided with screw fixing holes corresponding to the screw insertion holes 24a. By tightening screws from below, each contact portion 24 is attached to the main board 13. It is connected by screwing. Although not shown, the dust-proof cover 22 is formed with a slit-like hole through which the connection cable 20 is passed.

  Next, the operation of the above configuration will be described. Since the main body 11 of the car navigation device having the above configuration is mounted under the passenger seat of the passenger compartment, for example, dust that has fluttered from the carpet on the floor in the passenger compartment is indicated by an arrow A in FIG. There is a risk of entering the inside of the housing 12 from the gap between the connector 18 and the opening 12a on the back surface of the body 12. On the other hand, since the DVD drive device 14 uses a precision optical device for the data reading unit, there is a situation in which intrusion of dust or the like must be avoided. In this embodiment, since the dust-proof cover 22 is provided in the housing 12 so as to cover the DVD drive device 14, entry of dust into the DVD drive device 14 is prevented as much as possible, and the reading unit has good reading performance. Can be secured.

  In the DVD drive device 14, the internal data reading unit becomes a source of electrical noise, and the electrical noise has an effect on the main board 13 (for example, GPS signal reception performance deteriorates). there were.

  On the other hand, in the present embodiment, since the dust-proof cover 22 that covers the DVD drive device 14 is made of metal, the effect of shielding electrical noise generated in the DVD drive device 14 can be obtained. In addition, since the ground pattern of the main board 13 is electrically connected (grounded) to the housing 12 that functions as a stable ground via the dust-proof cover 22, the grounding of the main board 13 is strengthened. And can be effectively prevented from being affected by electrical noise.

  In this case, since the contact portion 24 and the contact piece portion 23 are integrally provided on the dust-proof cover 22, a simple configuration can be achieved without increasing the number of parts, unlike the case where the conventional contact spring 8 is added. Can do. Since the contact portion 24 is drawn on the metal plate constituting the dust cover 22 and the material is continuous, it is a matter of course that there is no dust intrusion or noise leakage from this portion. In addition, since the contact portion 24 is screwed to the main substrate 13, the electrical connection between the contact portion 24 and the ground pattern is more reliably performed. Furthermore, since the contact piece portion 23 that forms the plate shape of the dust cover 22 is elastically brought into surface contact with the inner surface of the housing 12 due to its own spring property, the contact piece portion 23 is stably attached to the inner surface of the housing 12. Contact and electrical connection can be made reliably.

  As described above, according to the present embodiment, the dust cover 22 is provided in the main body 11 of the car navigation device configured to incorporate the DVD drive device 14 and the main board 13 in the housing 12 and covers the DVD drive device 14. Is provided with a contact portion 24 connected to the ground pattern of the main board 13 and a contact piece portion 23 that contacts the housing 12 on the dust-proof cover 22. The DVD drive device 14 can be protected against dust, and noise generated from the DVD drive device 14 can effectively prevent the main board 13 from being adversely affected with a simple configuration. It plays.

  In the above embodiment, the present invention is applied to the main body 11 (navigator ECU) of the car navigation device. However, in addition, a drive unit and an electronic circuit, such as a car audio device that reproduces CD music and DVD video, etc. The present invention can be applied to all in-vehicle electronic devices having a substrate in a housing. In this case, the storage medium is not limited to the DVD and CD, but may be a recording medium using other light / magnetism such as a hard disk, and of course, a drive unit corresponding to the storage medium is used.

  In addition, the dust cover is not limited to a metal plate, and may be, for example, a plastic plated metal. Also, regarding the arrangement of the drive unit and the electronic circuit board in the housing, the drive unit is on the upper side and the electronic unit is on the lower side. Various modifications such as providing a circuit board are possible. Various modifications can be made to the configuration and shape of the housing. Furthermore, the present invention can be implemented with appropriate modifications within a range that does not depart from the gist, such as the screw connection between the contact portion of the dust cover and the electronic circuit board may be omitted.

1 shows an embodiment of the present invention, and is a vertical right side view schematically showing a configuration of a main body portion of a car navigation device. Disassembled perspective view of main unit Perspective view of main body Longitudinal front view of the lower half of the main unit Longitudinal right side view of the main body at a position different from FIG. 1 equivalent diagram showing a conventional example

Explanation of symbols

  In the drawings, 11 is a main body of a car navigation device (vehicle-mounted electronic device), 12 is a housing, 12a is an opening, 13 is a main board (electronic circuit board), 14 is a DVD drive device (drive unit), and 15 is the top. Case, 16 is a lower case, 18 is a connector, 20 is a connection cable, 22 is a dust cover, 23 is a contact piece (contact portion), 24 is a contact portion, and 24a is a screw insertion hole.

Claims (4)

A vehicle-mounted electronic device including a drive unit that reads data from a storage medium and an electronic circuit board in a metal casing, and a dustproof cover that covers the drive unit,
The dust cover has conductivity, and
An in-vehicle electronic apparatus comprising a contact portion electrically connected to a ground pattern of the electronic circuit board and a contact portion in contact with the housing integrally provided on the dust-proof cover.   The in-vehicle electronic device according to claim 1, wherein the dustproof cover is made of a metal plate, and the contact portion is integrally formed with the dustproof cover by drawing.   The in-vehicle electronic device according to claim 1, wherein a contact portion of the dustproof cover is connected to the electronic circuit board by screwing.   The contact portion of the dustproof cover has a plate shape that comes into surface contact with the inner surface of the housing, and is configured to elastically contact the inner surface of the housing with its own spring property. The in-vehicle electronic device according to any one of claims 1 to 3.

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