JP2010145181A - Vehicular display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic device that includes a first circuit board and a second circuit board which are grounded and allows electric connection between the circuit boards to be surely established. <P>SOLUTION: A combination meter 100 includes: a main circuit board 20 on which a socket-side connector 22 is to be mounted; an image plotting circuit board 30 that is arranged on the main circuit board 20 at a mounting face 20a side of the socket-side connector 22, is to be provided with a plug-side connector 32 fittable to the socket-side connector 22 and includes an earth circuit 38; and a board case 40 that is formed of a conductive material and includes a first attachment face 42a to be attached to the main circuit board 20 at an image plotting circuit board 30 side and a second attachment face 43a to be attached to the image plotting circuit board 30 at a main circuit board 20 side and to be connected to the earth circuit 38. The board case holds the main circuit board 20 and the image plotting circuit board under a condition that the socket-side connector 22 is fitted to the plug-side connector 32. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic device in which a plurality of circuit boards are electrically connected to each other.

  Conventionally, an electronic device shown in FIG. 4 is known as a kind of wiring for electrically connecting a plurality of circuit boards. This electronic device includes a first circuit board 920 on which a connector 922 is mounted, a second circuit board 930 on which a connector 932 is mounted on the first circuit board side, and a flexible printed circuit board that electrically connects the connector 922 and the connector 932 ( FPC) 923.

  In recent years, a configuration in which the first circuit board 920 and the second circuit board 930 are directly electrically connected without using the FPC 932 has been desired due to demands for downsizing and reduction in the number of components. As a technique for realizing the direct electrical connection between the circuit boards, for example, the invention of Patent Document 1 includes a first circuit board provided with an electrical contact portion, and a contact-type connector in surface contact with the electrical contact portion. And a second circuit board mounted on the board. And the fastening force which fastens the 2nd circuit board to the 1st circuit board forms the electrical connection of an electrical contact part and a contact type connector. A configuration in which this contact type connector is used in the electronic device shown in FIG. 4 is conceivable.

However, in addition to the configuration described above, the electronic device shown in FIG. 4 has a first mounting surface that is attached to the second circuit board side of the first circuit board, and a side surface opposite to the first circuit board side of the second circuit board. The holding member 940 which has a 2nd attachment surface attached via the metal collar 940a and consists of an electroconductive material is provided. Furthermore, the second circuit board 930 has a ground circuit, and the ground circuit is grounded to the holding member 940 via the second mounting surface. When a contact type connector as disclosed in Patent Document 1 is used for this electronic device, the second circuit is mounted on the peripheral portion of the second circuit board 930 and occupies the peripheral portion. This makes it difficult to ground the grounding circuit of the substrate 930 to the holding member 940.
Japanese Patent Laid-Open No. 11-6747

  Therefore, in the electronic device shown in FIG. 4, a configuration is conceived in which a second connector that can be directly fitted to the first connector is mounted on the second circuit board. However, in the state where the first circuit board 920 and the second circuit board 930 are held by the holding member, a large number of tolerances that cause the relative positions in the fitting direction of the first connector and the second connector to vary are accumulated. It ends up. Specifically, this tolerance includes tolerance due to mounting of the first connector on the first circuit board, dimensional tolerance from the first mounting surface to the second mounting surface of the holding member 940, flatness of the metal collar 940a, second These are the board thickness tolerance of the circuit board 930 and the tolerance caused by mounting the second connector on the second circuit board 930. Strict tolerance management of the holding member 940, the metal collar 940a, and the second circuit board 930 is required to reduce the accumulation of accumulated tolerances and to securely fit the first connector and the second connector. . Therefore, it has been difficult to reduce variations in relative position between the first connector and the second connector.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic device in which a second circuit board is grounded and an electrical connection between the circuit boards is reliably formed.

  In order to achieve the above-mentioned goal, in the invention according to claim 1, the first circuit board on which the first connector is mounted, the first connector on the mounting surface side of the first connector of the first circuit board, A second circuit board on which a second connector that can be fitted is mounted and having a ground circuit, a first mounting surface that is attached to the second circuit board side of the first circuit board, and a first circuit board of the second circuit board A second mounting surface that is mounted on the side and connected to the ground circuit, and holds the first circuit board and the second circuit board in a state in which the first connector and the second connector are fitted, and is made of a conductive material. And a member.

  According to this invention, the first circuit board is attached to the first attachment surface of the holding member, and the second circuit board is attached to the second attachment surface, so that the first circuit board and the second circuit board are attached to the holding member. It will be held. In this holding state, the factors causing the relative position in the fitting direction of the first connector and the second connector to vary are the tolerance due to the mounting of the first connector on the first circuit board, the second circuit of the second connector. It is an accumulation of tolerances due to mounting on the substrate and dimensional tolerances from the first attachment surface to the second attachment surface of the holding portion. Among these tolerances, in particular, by managing the dimensional tolerance from the first mounting surface to the second mounting surface, the accumulation of accumulated tolerances is reduced. Therefore, it becomes easy to reduce variation in the relative position between the first connector and the second connector, and the first connector and the second connector can be reliably fitted. In addition, when the holding member having the second mounting surface connected to the ground circuit is made of a conductive material, the ground circuit is reliably grounded. Therefore, it is possible to provide an electronic device in which the second circuit board is grounded and the electrical connection between the first circuit board and the second circuit board is reliably formed.

  Here, the mounting position of the first connector varies in the planar direction along the surface of the first circuit board. Similarly, the mounting position of the second connector varies in the planar direction along the surface of the second circuit board. Therefore, the invention according to claim 2 is characterized in that the second circuit board is positioned by fitting the second connector to the first connector in a planar direction along the surface of the first circuit board. According to this invention, the second connector is fitted to the first connector without position restriction in the planar direction of the first circuit board via the second circuit board. As described above, according to the configuration in which the second circuit board is positioned in the planar direction of the first circuit board by fitting the second connector to the first connector, the mounting positions of the first connector and the second connector may vary. Regardless, the fitting of the second connector to the first connector is surely performed. Therefore, the electrical connection between the first circuit board and the second circuit board can be reliably formed.

  In the invention according to claim 3, the first attachment surface includes a first adjustment portion that makes the attachment position of the holding member to the first circuit board freely adjustable in a planar direction along the surface of the first circuit board. It is characterized by comprising. In the invention according to claim 5, the second attachment surface allows the attachment position of the holding member to the second circuit board to be adjusted in a planar direction along the surface of the second circuit board. It comprises the part. According to the present invention, since the mounting positions of the first connector and the second connector on each circuit board vary, the first circuit board and the first connector defined by the fitting of the first connector and the second connector The relative position with respect to the two circuit boards will vary. Therefore, the holding member is provided by providing either or both of the first attachment surface and the second attachment surface with a first adjustment portion or a second adjustment portion whose position can be adjusted in the planar direction along the surface of each circuit board. The first circuit board or the second circuit board can be held while allowing variations in relative positions. Therefore, the holding member can hold the first circuit board and the second circuit board without generating a pressing force in the planar direction on the first connector and the second connector in the fitted state. Therefore, the reliability of electrical connection between the first circuit board and the second circuit board can be improved.

  In the invention according to claim 4, the first adjustment portion forms a first attachment hole in the first attachment surface, and the holding member is a fitting that fits in a state where a gap is formed between the first adjustment portion and the first attachment hole. The first circuit board is held by fastening the member. In the invention according to claim 6, the second adjustment portion forms a second mounting hole in the second mounting surface, and the holding member is a fastening that fits in a state where a gap is formed between the second adjusting portion and the second mounting hole. The second circuit board is held by fastening the member. According to this invention, the first circuit is formed by generating a gap between the first mounting hole and the second mounting hole and the fastening member for holding the first circuit board or the second circuit board on the holding member. The board and the second circuit board are adjusted in position in the plane direction and held by the holding member. In this way, the relative position of the first circuit board and the second circuit board can be allowed to vary with a simple configuration, and the reliability of the electrical connection between the first circuit board and the second circuit board can be improved.

  In the invention according to claim 7, the first circuit board is larger than the second circuit board, and includes a guide portion that contacts the outer surface of the second connector and guides the second connector to the fitting position. One connector is mounted. According to the present invention, the operator holds the second circuit board and brings the outer surface of the second connector into contact with the guide portion of the first connector mounted on the first circuit board larger than the second circuit board. These connectors are fitted together. By the action of guiding the second connector of the guide portion of the first connector to the fitting position, the fitting between the connectors is reliably achieved. In addition, according to the operation of attaching the second circuit board to be smaller to the larger first circuit board, the fitting operation in a state where the first connector and the second connector are visually recognized can be facilitated. . By these, the certainty of the fitting of the second connector to the first connector can be enhanced.

  The invention according to claim 8 is characterized in that a display device unit is connected to the first circuit board, and the second circuit board forms a drawing circuit connected to the display device unit. As described above, according to the holding of the first circuit board and the second circuit board by the holding member, electrical connection between the circuit boards by reliable fitting of the connectors and reliable grounding of the ground circuit can be achieved. Can do. In general, since the amount of signal transmitted from the drawing circuit to the display unit is large, each connector that electrically connects the first circuit board and the second circuit board is increased in size and is difficult to fit. In addition, since a large amount of electromagnetic noise tends to be emitted from the drawing circuit, the importance of grounding the ground circuit is increased. Therefore, the invention according to claim 8 is particularly suitable for an electronic device that requires electrical connection and grounding between the first circuit board to which the display unit is connected and the second circuit board that forms the drawing circuit. .

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In addition, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol to the corresponding component in each embodiment.

(First embodiment)
FIG. 1 is a front view of a combination meter 100 according to a first embodiment of the present invention. The combination meter 100 is accommodated in an instrument panel provided in the vehicle interior of the vehicle, and the front side shown in FIG. 1 is arranged toward the driver's seat side.

(Basic configuration)
The combination meter 100 is an electronic device that acquires and displays information about a vehicle. The display of the combination meter 100 includes a pointer display unit 11 that displays information related to vehicle information as a pointer, a multi-display unit 13 that displays information related to vehicle information as an image, and a ground portion 15 that is the background of these display units 11 and 13. Etc. are constituted. Specifically, the pointer display unit 11 includes a speedometer 11a and a tachometer 11b. The multi display unit 13 is an image displayed on the liquid crystal display device 60, and includes an od trip meter image 13a, a shift indicator image 13b, a door warning image 13c, and the like.

  FIG. 2 shows the mechanical configuration of the combination meter 100. The combination meter 100 includes an instrument housing 50, a decorative panel 55, a main circuit board 20 to which the liquid crystal display device 60 described above is connected, a drawing circuit board 30, a board case 40, and a cover 46.

  The instrument housing 50 is formed of a resin material such as polypropylene. The instrument housing 50 supports the decorative panel 55 on the front side in the display direction, and is in contact with the main circuit board 20 on the back side in the display direction. The decorative panel 55 is made of a resin material such as polypropylene, and is coated on the front side in the display direction to prevent irregular reflection of light. The decorative panel 55 forms a ground portion 15 (see FIG. 1) in the display of the combination meter 100. Further, when the opening 55a is formed in the decorative panel 55, each image displayed on the liquid crystal display device 60 is visually recognized from the front in the display direction.

  The liquid crystal display device 60 includes a dot matrix TFT transmissive liquid crystal panel having a plurality of pixels arranged in a matrix, and a backlight that illuminates and transmits the panel from the back side in the display direction. The TFT transmissive liquid crystal panel realizes display of each image (see FIG. 1) by driving each pixel. Each pixel of the TFT transmissive liquid crystal panel is composed of three sub-pixels provided with red, green, and blue color filters, respectively, and can display an image in full color. Further, the backlight includes a light emitting diode and a diffusion plate, and realizes illumination with no spots on the TFT transmission liquid crystal panel.

  The main circuit board 20 is a two-layer board made of a paper phenol-based hard board and provided with electric circuits on both sides. A liquid crystal display device 60 is installed in front of the main circuit board 20 in the display direction, and is electrically connected to an electric circuit of the circuit board 20. In addition, the main circuit board 20 is provided with a plurality of fastening holes 24. A socket-side connector 22 connected to the electric circuit is mounted on the mounting surface 20 a on the rear side in the display direction of the main circuit board 20 with the fitting direction being orthogonal to the main circuit board 20. . In this embodiment, the tolerance generated in the fitting direction with respect to the mounting surface 20a of the socket-side connector 22 is specifically within ± 0.1 mm.

  The drawing circuit board 30 is made of a glass epoxy hard substrate, and is a multilayer board in which a plurality of insulating materials and a conductive material forming an electric circuit are laminated. The drawing circuit board 30 is arranged along the main circuit board 20 on the back side in the display direction of the circuit board 20. The electric circuit of the drawing circuit board 30 forms a drawing circuit 37 for drawing an image mainly displayed on the liquid crystal display device 60 and a ground circuit 38. The drawing circuit board 30 is provided with a plurality of fastening holes 34. A part of the drawing circuit 37 provided on the drawing circuit board 30 is exposed to the outer surface at the peripheral edge of the fastening hole 34 and is in contact with the board case 40 so as to be energized. A plug-side connector 32 connected to an electric circuit is mounted on the mounting surface 30 a on the main circuit board 20 side of the drawing circuit board 30 so that the fitting direction is perpendicular to the drawing circuit board 30. Yes. The plug-side connector 32 can be fitted with the socket-side connector 22 mounted on the main circuit board 20. Further, the tolerance generated in the fitting direction with respect to the mounting surface 30a of the plug-side connector 32 is specifically within ± 0.1 mm.

  The board case 40 is formed of a conductive metal material such as iron, for example, and is electrically connected to a structural member made of a conductive material constituting the vehicle along with the mounting of the combination meter 100. The substrate case 40 has a first attachment portion 42 and a second attachment portion 43. A planar first mounting surface 42 a is formed on the first mounting portion 42 along the drawing circuit board 30 side of the main circuit board 20. The first mounting surface 42a is formed with a first mounting hole 42b orthogonal to the first mounting surface 42a. The main circuit board 20 is attached to the first attachment surface 42 a and held by the board case 40 by the fastening force of the screws 25 that are fastened through the first attachment holes 42 b and the fastening holes 24 of the main circuit board 20. It will be. The second mounting portion 43 is connected to the ground circuit 38 of the drawing circuit board 30 to ground the ground circuit 38.

  The cover 46 is formed in a container shape from a metal material such as iron, like the substrate case 40. The cover 46 is fitted to the substrate case 40 from the outside, and is fixed to the substrate case 40 by a claw portion (not shown). The cover 46 accommodates the drawing circuit board 30, shields electromagnetic wave noise radiated into the space by the drawing circuit board 30, and is grounded to the contacting substrate case 40.

(Characteristic part)
Hereinafter, the characteristic part of the combination meter 100 by 1st embodiment of this invention is demonstrated.

  The drawing circuit board 30 is a circuit board formed in a small size with a smaller area than the main circuit board 20. The ground circuit 38 provided on the drawing circuit board 30 is exposed to the outer surface at the peripheral edge of the fastening hole 34 on the main circuit board 20 side. Further, the plug-side connector 32 mounted on the drawing circuit board 30 and the socket-side connector 22 mounted on the main circuit board 20, specifically a connector with 24 poles, having a length of about 30 mm It is formed in size. In addition, the socket-side connector 22 includes a pair of guide portions 22a that guide the plug-side connector 32 to the fitting position on both ends in the longitudinal direction. The plug-side connector 32 is inserted into the plug-side connector 32 along the guide portion 22a with the outer surface being in contact with the guide portion 22a. In addition, each of the connectors 22 and 32 can ensure reliable electrical connection by suppressing variation in relative position in the fitting direction within ± 0.8 mm.

  The first mounting hole 42b formed in the first mounting surface 42a of the substrate case 40 is formed to have a larger diameter than the outer diameter of the male screw portion of the screw 25, and a gap is formed between the first mounting hole 42b and the screw 25. It will be fitted in the state. The first attachment hole 42b constitutes an adjustable first adjustment portion 42d for adjusting the attachment position of the substrate case 40 in the planar direction along the surface of the main circuit board 20. The second mounting portion 43 of the substrate case 40 has a second mounting surface 43a, and a second mounting hole 43b and a rib portion 43c are formed on the second mounting surface 43a. The second mounting surface 43a is formed in a planar shape along the mounting surface 30a side of the drawing circuit board 30 and is in contact with the mounting surface 30a side. The tolerance of the inter-surface distance from the second mounting surface 43a to the first mounting surface 42a is specifically managed within ± 0.3 mm. In addition, the rib portion 43 c is formed in a shape along the outer shape of the drawing circuit board 30 in the orthogonal direction from the second mounting surface 43 a toward the back side in the display direction. Therefore, the rib part 43c can roughly position the board case 40 and the drawing circuit board 30. A female screw portion corresponding to the male screw portion of the screw 35 is provided on the inner peripheral surface of the second mounting hole 43b. When the screw 35 is fastened through the second mounting hole 43b, the drawn circuit board 30 is mounted on the second mounting surface 43a and held by the board case 40. The second attachment surface 43 a attached to the drawing circuit board 30 is in direct contact with the ground circuit 38 exposed on the outer surface of the drawing circuit board 30 to ground the earth circuit 38.

  In the combination meter 100 having the above-described configuration, an operation process in which the drawing circuit board 30 is connected to the main circuit board 20 and the circuit boards 20 and 30 are held by the board case 40 will be described below.

  First, the operator roughly performs relative positioning between the board case 40 and the printed circuit board 30 by using the rib portion 43 c of the board case 40. The operator passes the screw 35 through the positioned fastening hole 34 of the drawn circuit board 30 and fastens the screw 35. By being attached to the second attachment surface 43 a by fastening a plurality of screws 35, the drawn circuit board 30 is held by the board case 40. Subsequently, the operator performs an operation of attaching the board case 40 integrated with the drawing circuit board 30 to the main circuit board 20. The operator causes the plug-side connector 32 to be inserted into and fitted into the socket-side connector 22 by bringing the outer surface of the plug-side connector 32 mounted on the drawing circuit board 30 into contact with the guide portion 22a of the socket-side connector 22. . At this time, the relative position of the drawing circuit board 30 in the planar direction along the surface of the main circuit board 20 is determined by fitting the plug-side connector 32 to the socket-side connector 22. The board case 40 positioned with respect to the main circuit board 20 together with the drawing circuit board 30 by fitting the connectors 22 and 32 is then attached to the main circuit board 20 by fastening screws 25. According to the first mounting hole 42b having a diameter larger than that of the male screw portion of the screw 25, an operator can easily attach the main circuit board 20 to the board case 40 in a position-adjusted state. Can do. By fastening the screws 35, the substrate case 40 holds the main circuit board 20.

  In the first embodiment described so far, the relative position of the socket side connector 22 and the plug side connector 32 in the fitting direction varies in a state where the substrate case 40 holds the main circuit board 20 and the drawing circuit board 30. The factor that causes this is the accumulation of the following tolerances. That is, the tolerance due to the mounting of the socket side connector 22 on the main circuit board 20, the tolerance due to the mounting of the plug side connector 32 on the drawing circuit board 30, and the second from the first mounting surface 42 a of the board case 40. This is an accumulation of dimensional tolerances up to the mounting surface 43a. Among these tolerances, in particular, when the dimensional tolerance from the first attachment surface 42a to the second attachment surface 43a is managed within ± 0.3 millimeters, the accumulated tolerances are accumulated in the connectors 22, 32. It is reduced to within ± 0.8 millimeters where a reliable electrical connection is made. Thus, according to the variation in the relative position of the socket-side connector 22 and the plug-side connector 32 in the fitting direction being reduced, the socket-side connector 22 and the plug-side connector 32 are securely fitted. . In addition, when the substrate case 40 having the second mounting surface 43a connected to the ground circuit 38 is made of a conductive material, the ground circuit 38 is reliably grounded. Therefore, it is possible to provide the combination meter 100 in which the drawing circuit board 30 is grounded and the electrical connection between the main circuit board 20 and the drawing circuit board 30 is reliably formed.

  In addition, the mounting position of the socket-side connector 22 varies in the planar direction along the surface of the main circuit board 20. Similarly, the mounting position of the plug-side connector 32 also varies in the planar direction along the surface of the drawing circuit board 30. Therefore, in the first embodiment, the plug-side connector is configured by positioning the drawing circuit board 30 and the main circuit board 20 in the planar direction by fitting the plug-side connector 32 to the socket-side connector 22. 32 is fitted to the socket-side connector 22 without any position restriction. Therefore, regardless of variations in the mounting positions of the socket-side connector 22 and the plug-side connector 32 on the circuit boards 20 and 30, the connectors 22 and 32 are reliably fitted to each other. Therefore, the electrical connection between the main circuit board 20 and the drawing circuit board 30 can be reliably formed.

  In the first embodiment, due to variations in the mounting positions of the socket-side connector 22 and the plug-side connector 32 on the circuit boards 20 and 30, the main circuit board 20 positioned by fitting the connectors 22 and 32 is drawn. The relative position with respect to the circuit board 30 varies. In view of this, the board case 40 is provided on the first mounting surface 42a by providing a first adjustment portion 42d in which the position of the board case 40 to the main circuit board 20 can be adjusted in the plane direction of the circuit board 20. , 30 can be held while allowing variations in relative positions. Specifically, the first adjusting portion 42d is configured by a first mounting hole 42b and the like that are fitted in a state in which a gap is formed between the screw 25 for holding the main circuit board 20 in the board case 40. Yes. In this way, variations in the relative positions of the main circuit board 20 and the drawing circuit board 30 are allowed with a simple configuration, and even the board case 40 in a position-adjusted state can be easily attached to the main circuit board 20. It is. Therefore, the board case 40 holds the main circuit board 20 and the drawing circuit board 30 without generating a pressing force in the planar direction on the socket-side connector 22 and the plug-side connector 32 in the fitted state. Therefore, the reliability of the electrical connection between the main circuit board 20 and the drawing circuit board 30 can be improved.

  Furthermore, in the first embodiment, the substrate case 40 securely holds the main circuit board 20 and the drawing circuit board 30 by fastening the screws 25 and the screws 35. Therefore, even when the combination meter 100 is mounted on a vehicle and used in an environment with a lot of vibrations, the fitting state between the socket-side connector 22 and the plug-side connector 32 is maintained. Therefore, it is possible to provide the combination meter 100 in which the electrical connection between the main circuit board 20 and the drawing circuit board 30 is maintained for a long period even in an environment with a lot of vibrations.

  In addition, in the first embodiment of the present invention, the operator holds the drawing circuit board 30 smaller than the main circuit board 20, and connects the plug-side connector 32 on the drawing circuit board 30 side to the socket on the main circuit board 20 side. It can be inserted into the side connector 22 and fitted. Since the drawing circuit board 30 is smaller than the main circuit board 20, it is possible to realize a fitting operation in a state where the operator sees the socket-side connector 22 and the plug-side connector 32. In addition, the workability of fitting can be improved by inserting the plug-side connector 32 along the guide portion 22a of the socket-side connector 22. By reducing the operator's erroneous work by these, the certainty of the fitting between the connectors 22 and 32 can be enhanced.

  In addition, in the first embodiment, the liquid crystal display device 60 is connected to the main circuit board 20, and the drawing circuit board 30 forms a drawing circuit connected to the liquid crystal display device 60. As described above, according to the holding of the main circuit board 20 and the drawing circuit board 30 by the board case 40, the electrical connection between the circuit boards 20, 30 by the reliable fitting of the connectors 22, 32, and the ground circuit 38 reliable grounding can be achieved. In general, since the amount of signal transmitted from the drawing circuit to the liquid crystal display device 60 is large, each of the connectors 22 and 32 for electrically connecting the main circuit board 20 and the drawing circuit board 30 is a large one having a large number of poles. It becomes difficult to fit. In addition, a large amount of electromagnetic noise is emitted from the drawing circuit. Therefore, the present invention is particularly suitable for the combination meter 100 that requires electrical connection between the main circuit board 20 to which the liquid crystal display device 60 is connected and the drawing circuit board 30 forming the drawing circuit and grounding of the earth circuit 38. .

  In the present embodiment, the main circuit board 20 is the “first circuit board” described in the claims, the drawing circuit board 30 is the “second circuit board”, and the socket-side connector 22 is the claim. In the “first connector”, the plug-side connector 32 is in the “second connector” in the claims, the ground circuit 38 is in the “ground circuit” in the claims, and the screws 25 and 35 are in the claims. The substrate case 40 corresponds to the “holding member” described in the claims, and the liquid crystal display device 60 corresponds to the “display device portion” described in the claims.

(Second embodiment)
The second embodiment of the present invention is a modification of the first embodiment. As shown in FIG. 3, in the substrate case 240 in the second embodiment, the second adjustment portion is provided on the second attachment surface 43 a instead of the first adjustment portion 42 d provided on the first attachment surface 42 a in the first embodiment. 243d is provided.

  The second adjustment unit 243d in the second embodiment enables adjustment of the mounting position of the circuit board 30 in the planar direction when the drawing circuit board 30 is attached to the board case 240. Specifically, the second adjusting portion 243d is configured by a second mounting hole 243b having a diameter larger than that of the external thread portion of the screw 35 formed on the second mounting surface 43a. In addition, in 2nd embodiment, the rib part 43c is not formed in the 2nd attachment surface 43a. In the combination meter 200 having the above-described configuration, an operation process for electrically connecting the main circuit board 20 and the drawing circuit board 30 and holding the circuit boards 20 and 30 by the board case 240 will be described below.

  First, the operator attaches the board case 240 to the main circuit board 20 by fastening the screws 25. By being attached to the first attachment surface 42 a by fastening a plurality of screws 25, the main circuit board 20 is held by the board case 240. Subsequently, the operator grasps the drawing circuit board 30 and inserts the plug-side connector 32 mounted on the drawing circuit board 30 into the socket-side connector 22 mounted on the main circuit board 20 so as to be fitted. At this time, the relative position of the drawing circuit board 30 in the planar direction along the surface of the main circuit board 20 is determined by fitting the plug-side connector 32 to the socket-side connector 22. The drawing circuit board 30 positioned by the fitting of the plug-side connector 32 is then attached to the board case 240 by fastening screws 35. According to the second mounting hole 243b having a diameter larger than that of the male screw portion of the screw 35, the operator can easily mount the drawing circuit board 30 in a position-adjusted state on the board case 240. Can do. By fastening the screws 35, the substrate case 240 holds the drawn circuit board 30.

  The board case 240 of the second embodiment as described above allows variations in the relative positions of the main circuit board 20 and the drawing circuit board 30 in the same manner as the board case 40 of the first embodiment. The substrates 20 and 30 can be held. In addition, the tolerance of the relative position of the main circuit board 20 and the drawing circuit board 30 is realized with a simple configuration. Therefore, the board case 240 holds the main circuit board 20 and the drawing circuit board 30 without generating a pressing force in the planar direction on the socket-side connector 22 and the plug-side connector 32 in the fitted state. A highly reliable electrical connection between the circuit board 20 and the drawing circuit board 30 can be realized.

(Other embodiments)
Although a plurality of embodiments of the present invention have been described above, the present invention is not construed as being limited to these embodiments, and can be applied to various embodiments without departing from the scope of the present invention. .

  In the above embodiment, the relative positioning of the drawing circuit board 30 and the main circuit board 20 is performed by fitting the plug-side connector 32 to the socket-side connector 22. However, each circuit board 20, 30 or board case 40, 240 may have a configuration for performing relative positioning between the drawing circuit board 30 and the main circuit board 20. Specifically, a positioning pin and a hole for fitting with the pin may be provided in each circuit board 20, 30 or board case 40, 240.

  In the above embodiment, the substrate cases 40 and 240 only ground the ground circuit 38 of the drawing circuit board 30. However, the main circuit board 20 is grounded to the board cases 40 and 240 by exposing a part of the earth circuit formed on the main circuit board 20 to the outer surface and bringing it into contact with the first mounting surface 42a. May be.

  In the first embodiment, the first attachment surface 42a is provided with the first adjustment portion 42d capable of adjusting the position of the attachment of the board case 40 to the main circuit board 20 in the plane direction of the circuit board 20. In the second embodiment, when the drawing circuit board 30 is attached to the board case 240, the second adjustment portion 243d that enables adjustment of the attachment position of the circuit board 30 in the planar direction is provided on the second attachment surface 43a. Was provided. However, the first adjustment unit 42d and the second adjustment unit 243d may be provided together in the substrate case, or may not be provided together.

  In the said embodiment, the 1st adjustment part and the 2nd adjustment part were comprised by making it fit in the state which produced the clearance gap between each attachment hole and each fastening member. However, the first adjustment unit and the second adjustment unit are not limited to this configuration. For example, instead of fastening the circuit boards 20 and 30 to the board case by the fastening members, the circuit boards 20 and 30 may be attached to the board case with their positions adjusted by soldering or the like.

  In the above embodiment, the operator holds the drawing circuit board 30 that is smaller than the main circuit board 20 and inserts the plug-side connector 32 into the socket-side connector 22 on the main circuit board 20 side so as to be fitted. However, the operator may hold the large circuit board side and insert and fit the connector mounted on the large circuit board side into the connector mounted on the small circuit board side. In addition, the circuit board on which the plug-side connector and the socket-side connector are mounted is not limited.

  In the above embodiment, the present invention is applied to a combination meter, and a main circuit board to which a liquid crystal display device 60 included in the combination meter 100 is connected and a drawing circuit board on which a drawing circuit for drawing an image is formed are held. The substrate case has been described as an example. However, the present invention can be applied to any electronic device in which adjacent circuit boards are directly electrically connected to each other by a connector and includes a holding member that holds the adjacent circuit boards together.

It is a front view which shows the display of the combination meter by 1st embodiment of this invention. It is a figure which shows the mechanical structure of the combination meter by 1st embodiment of this invention, Comprising: It is the II-II sectional view taken on the line of FIG. It is a figure which shows the mechanical structure of the combination meter by 2nd embodiment of this invention. It is a figure which shows the mechanical structure of the conventional combination meter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Pointer display part, 11a Speedometer, 11b Tachometer, 13 Multi display part, 13a Odo trip meter image, 13b Shift indicator image, 13c Door warning image, 15 Ground part, 20 Main circuit board (1st circuit board), 22 Socket side connector (first connector), 24 fastening hole, 25 screw (fastening member), 30 drawing circuit board (second circuit board), 32 plug side connector (second connector), 34 fastening hole, 35 screw (fastening member) ), 38 Ground circuit (ground circuit), 40, 240 Substrate case (holding member), 42 First mounting portion, 42a First mounting surface, 42b First mounting hole, 42d First adjustment portion, 43 Second mounting portion, 43a Second mounting surface, 43b Second mounting hole, 43c Rib portion, 243d Second adjusting portion, 46 Cover, 50 Instrument housing Body, 55 decorative panel, 55a opening, 60 liquid crystal display (display device), 100,200 combination meter (electronic device)

Claims (8)

A first circuit board on which the first connector is mounted;
A second circuit board which is disposed on the mounting surface side of the first connector of the first circuit board and has a ground circuit and a second connector which can be fitted to the first connector;
A first attachment surface attached to the second circuit board side of the first circuit board; and a second attachment surface attached to the first circuit board side of the second circuit board and connected to the ground circuit. An electronic apparatus comprising: a holding member that holds the first circuit board and the second circuit board in a state in which the first connector and the second connector are fitted, and is made of a conductive material.   The electronic device according to claim 1, wherein the second circuit board is positioned by fitting the second connector to the first connector in a planar direction along the surface of the first circuit board.   The first attachment surface includes a first adjustment portion that allows a position of the holding member to be attached to the first circuit board to be adjusted in a planar direction along the surface of the first circuit board. The electronic device according to claim 2. The first adjusting portion forms a first mounting hole in the first mounting surface,
The electronic device according to claim 3, wherein the holding member holds the first circuit board by fastening of a fastening member that is fitted in a state where a gap is generated between the holding member and the first mounting hole.   The second attachment surface includes a second adjustment portion that allows the position of the holding member to be attached to the second circuit board to be adjusted in a planar direction along the surface of the second circuit board. The electronic device according to any one of claims 2 to 4. The second adjusting portion forms a second mounting hole in the second mounting surface,
The electronic device according to claim 5, wherein the holding member holds the second circuit board by fastening a fastening member that is fitted in a state where a gap is generated between the holding member and the second mounting hole.   The first circuit board is larger than the second circuit board, and is mounted with a first connector having a guide portion that contacts the outer surface of the second connector and guides the second connector to a fitting position. The electronic device according to claim 1, wherein the electronic device is an electronic device. A display unit is connected to the first circuit board,
The electronic device according to claim 1, wherein the second circuit board forms a drawing circuit connected to the display device unit.

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