JPH11354945A - Printed circuit board and electronic equipment equipped with the printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed circuit board and electronic equipment for securing stable circuit operation by preventing noise from being generated at and for entering the printed circuit board, regardless of the direction of arrangement. SOLUTION: An electrical conduction part 61 is provided at an outer peripheral edge part in printed circuit boards 11-14 accommodated in an armor case 2 of electronic equipment and is electrically connected to a grounding means 2a which is formed on the inner-periphery surface of the armor case 2 via a retaining member 71. Since the electrical conduction part 61 is provided at the end part of the printed circuit boards 11-14, electrical connection to the grounding means 2a can be made merely by making the conductive retaining member 71 interposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board housed in a housing together with a drive system of an electronic device and electrically controlling the drive system, and an electronic device using the circuit board. A projection display device comprising a lamp, an optical system for optically processing a light beam emitted from the light source lamp to form an optical image according to image information, and a projection lens for enlarging and projecting the optical image on a projection surface. Can be used for

[0002]

2. Description of the Related Art Conventionally, an electronic apparatus including a drive system, a circuit board for electrically controlling the drive system, and a housing for housing the drive system and the circuit board therein has been used. Such electronic devices include, for example, a light source lamp, an optical system that optically processes a light beam emitted from the light source lamp to form an optical image according to image information, and enlarges the optical image on a projection surface. A drive system including a projection lens for projecting,
A projection display device including a circuit board for electrically controlling the light source lamp, the optical system, and the like, and a housing for accommodating the drive system and the circuit board is known.

In such a projection display device, a grounding means is provided on an inner peripheral surface of a housing to prevent radiation of noise and stabilize the operation of the circuit board. Are electrically connected to ensure a stable operation of the circuit board. Specifically, in the conventional projection display device, the circuit board is horizontally arranged above the optical system,
It is fixed to the inner peripheral surface of the housing with a plurality of fixing screws. The fixing screw is electrically connected to the above-described grounding means, and noise generated on the circuit board is radiated by the grounding means via the fixing screw, thereby stabilizing the operation of the circuit board.

[0004] By the way, such electronic devices tend to be lighter, smaller, and thinner, and the above-mentioned projection display devices have also been made lighter, smaller, and thinner. I have.

However, in the conventional projection display device, since the circuit board is arranged horizontally above the optical system, there is a limit in reducing the thickness. For this reason, it is conceivable to reduce the thickness of the projection display device by arranging the circuit board vertically on the side of the optical system.

[0006]

However, the projection type display device having such a circuit board arranged vertically has the following problems. That is, in consideration of stability at the time of installation and the like, the housing of the projection display device is generally formed in a substantially rectangular parallelepiped shape that is large in the horizontal direction and small in the vertical direction. Therefore, in the conventional projection display device in which the circuit boards are arranged horizontally, a wide circuit board corresponding to the planar shape of the housing is employed, and the number of fixing points by the fixing screws is increased, so that the circuit board and the grounding means are connected. The electrical connection was made sufficiently.

On the other hand, in a projection type display device in which circuit boards are arranged vertically, only a narrow circuit board corresponding to the height of the housing can be adopted, and the fixing position by fixing screws is limited. . Therefore, there is a problem that electrical connection between the circuit board and the grounding means via the fixing screw cannot be sufficiently performed. It is also conceivable to provide a dedicated connection line on the circuit board separately from the electrical connection by the fixing screw to achieve an electrical connection between the circuit board and the grounding means, but the structure of the circuit board is complicated. This is not desirable from the viewpoint of miniaturization of the apparatus.

An object of the present invention is to provide a circuit board that is housed in a housing together with a drive system of an electronic device and electrically controls the drive system, and an electronic device using the circuit board, regardless of the arrangement direction. It is an object of the present invention to provide a circuit board and an electronic device which can prevent generation of noise and jumping into the circuit board and ensure stable circuit operation.

[0009]

A circuit board according to the present invention is a circuit board housed in a housing, wherein the housing prevents radiation of noise generated inside the housing, and Grounding means is provided for preventing external noise from jumping into the housing, and the circuit board is provided on an outer peripheral edge thereof, and includes an electrically conductive portion electrically connected to the grounding means. It is characterized by being.

[0010] Here, as the above-mentioned electric conduction portion,
An electrically conductive portion provided entirely along the outer peripheral portion of the circuit board may be employed, or an electrically conductive portion provided at a part of the outer peripheral end portion may be employed. May be employed.

According to the present invention, since the electrical conduction portion is provided at the outer peripheral end of the circuit board, if the electrical conduction portion and the grounding means inside the housing are brought into contact, both of them can be contacted. The electrical connection is achieved, and the generation and jump of noise generated on the circuit board can be prevented regardless of the arrangement direction of the circuit board, and a stable circuit operation can be secured.

[0012] In the above, it is preferable to employ an electrical conduction portion constituted by a metal conduction portion formed on at least a part of the outer peripheral end of the circuit board as the electrical conduction portion. Specifically, the metal conducting portion can be formed by forming a metal plating layer on the outer peripheral edge of the circuit board, or by covering the outer peripheral edge of the circuit board with a metal plate.

When the metal conduction portion is formed of a metal plating layer, it can be formed, for example, as follows. First, a through hole having a long hole shape with a metal plating applied to an inner peripheral surface is formed in a circuit board for printed wiring. And
If the circuit board is cut so as to be divided along the long side direction of the long hole, the metal plating layer is exposed at the outer peripheral end of the circuit board, and a metal conduction portion can be formed.

If the metal conductive portion is formed by a metal plating layer, an electrical conductive portion can be formed simultaneously with the step of forming a through hole when forming a printed wiring on a circuit board. The manufacture of the substrate is facilitated. In addition, if the electrically conductive portion is formed of a metal plate covering the outer peripheral edge of the circuit board, the electrical conductive portion can be formed later after the circuit board is formed, and the outer peripheral edge of the circuit board can be formed. It is possible to easily form the electrical conduction portion continuously along.

Further, the electronic device according to the present invention is an electronic device including a housing for housing a circuit board therein, wherein the housing prevents radiation of noise generated inside the housing. A grounding means for preventing external noise from jumping into the inside of the housing, and a holding member electrically connected to the grounding means and holding the circuit board are provided. An electrical conduction portion is provided at an outer peripheral end of the circuit board and electrically connected to the grounding means. The electrical conduction portion and the grounding means are electrically connected to each other via the holding member. It is characterized by being connected.

According to the present invention, since the grounding means of the housing and the electrically conductive portion of the circuit board are electrically connected to each other via the holding member, a dedicated connection line or the like is separately provided on the circuit board. And the circuit board and the grounding means can be easily electrically connected.

In the above, as the above-mentioned holding member, a holding member composed of a metal member engaged with the circuit board may be adopted, but preferably, an elastic body which is deformed according to the contact state of the circuit board is used. It is good to adopt the holding member constituted from. Specifically, as the holding member, a band-shaped holding member including a sponge-like elastic member and a conductive sheet provided on the outer peripheral surface of the elastic member can be adopted.

That is, since the holding member is composed of the elastic member and the conductive sheet provided on the outer peripheral surface of the elastic member, the holding member is deformed in accordance with the contact state of the circuit board, and the grounding means and the electrical connection are made. Electrical connection with the electrical conduction part,
This can be reliably performed via the conductive sheet of the holding member.

Further, as the above-mentioned grounding means, a grounding means in which a metal plate is stuck inside the housing may be adopted.
Preferably, a grounding means made of shield plating formed on the inner surface of the housing is used.

That is, since the grounding means is composed of the shield plating layer formed on the inner surface of the housing, the grounding means can be easily formed in the outer case, and the grounding means can be simplified and the interior of the electronic device can be simplified. Can be simplified, and the size of the electronic device can be further reduced.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

(1) Overall Configuration of Device FIG. 1 is a plan view showing the internal structure of a projection display device 1 according to an embodiment of the present invention. This projection type display device 1 converts a light beam emitted from a light source lamp into red (R),
A format in which the light is separated into three primary colors of green (G) and blue (B), and the luminous flux of each of these colors is modulated according to image information through a modulation element such as a light valve, and is enlarged and displayed on a projection surface via a projection lens 6. belongs to. The projection display device 1 has an outer case 2, a projection lens 6 protruding from the front surface of the outer case 2, power supply units 7 a and 7 b housed inside the outer case 2, a light source lamp unit 8, and an optical unit. 10 and circuit boards 11 to 14.

The outer case 2 includes an upper case (not shown), a lower case 4, and a rear case 5, and a shield plating layer 2a is formed on an inner peripheral surface thereof, and the shield plating layer 2a constitutes a grounding means. doing. In FIG. 1, an intake port (not shown) for guiding cooling air to the inside of the apparatus is formed at a position on the bottom surface of the lower case 4 corresponding to the prism unit 910, and an intake port arranged above the intake port. The cooling air outside the device is forcibly taken into the device by a fan. Further, two front feet are provided at both ends of the lower case 4 in front of the apparatus, and rear feet are provided in a substantially central portion at the rear of the apparatus. The two front feet are configured to be able to advance and retreat in a direction protruding from the bottom surface of the lower case 4,
By adjusting the amount of protrusion of the front foot, the vertical position of the display screen on the projection surface can be changed.

Although not shown in FIG. 1, the rear case 5 is provided with an AC inlet for supplying external power and various input / output terminal groups. The AC inlet and the input / output terminal group are connected to the circuit board 11. To 14 are electrically connected. An exhaust port 160 for discharging cooling air is provided in the rear case 5 adjacent to the input / output terminal group. An exhaust fan 16 is arranged adjacent to the exhaust port 160, whereby the air inside the apparatus is forcibly discharged to the outside of the apparatus.

The power supply units 7a and 7b supply electric power to the optical unit 10 and the light source lamp unit 8, and are arranged on both sides of the optical unit 10, and are connected to the AC inlet provided in the rear case 5 described above. Connected. On the upper surfaces of the power supply units 7a and 7b, speakers 251R and 251L for audio output are provided. As described above, the power supply units 7a and 7b are provided with the optical unit 10 and the light source lamp unit 8.
, And also supplies power to the speakers 251R and 251L, the exhaust fan 16, and an intake fan (not shown).

The light source lamp unit 8 constitutes a light source portion of the projection display device 1 and has a light source device including a light source lamp 81 and a reflector 82 and a lamp housing for accommodating the light source device. The lamp replacement lid (not shown) formed on the bottom surface is configured to be removable together with the light source lamp.

The optical unit 10 is a unit that optically processes a light beam emitted from the light source lamp unit 8 to form an optical image corresponding to image information, and includes an illumination optical system 923, a color separation optical system 924, It is configured to include a modulation system 925 and a prism unit 910 as a color combining optical system. Illumination optical system 923 and color separation optical system 924
And the like are configured to be sandwiched vertically and held inside a light guide 901 having a predetermined optical path. The light guide 901 is fixed to the lower case 4 with fixing screws. The prism unit 910 is mounted and fixed on a head plate 903 which is a substantially L-shaped structure formed from an integrally molded product of magnesium. It is fixed with screws. Modulation system 9
25 is three liquid crystal light valves 925R, 925G, 9
25B, each liquid crystal light valve 925R, 9
25G and 925B are cubic prism units 91
It is stuck and fixed to the side surface of "0".

(2) Structure of Optical System Next, the structure of the optical system of the projection display 1 will be described with reference to the schematic diagram shown in FIG.

The illumination optical system 923 includes a reflection mirror 931 that bends the optical axis 1a of the light beam W emitted from the light source lamp unit 8 toward the front of the device, and a first lens plate 921 that is disposed with the reflection mirror 931 interposed therebetween. And a second lens plate 922. The first lens plate 921 has a plurality of rectangular lenses arranged in a matrix, and divides a light beam emitted from a light source into a plurality of partial light beams. Then, each partial light beam is collected near the second lens plate 922.

The second lens plate 922 has a plurality of rectangular lenses arranged in a matrix, and converts each partial light beam emitted from the first lens plate 921 into a liquid crystal light valve constituting a modulation system 925. 925R, 925G, 925
B (described later).

As described above, in the projection display apparatus 1 of this embodiment, the liquid crystal light valve 925 is provided by the illumination optical system 923.
Since the R, 925G, and 925B can be illuminated with light having substantially uniform illuminance, a projection image without illuminance unevenness can be obtained.

The color separation optical system 924 includes a blue-green reflecting dichroic mirror 941 and a green reflecting dichroic mirror 9.
42 and a reflection mirror 943. First, in the blue-green reflecting dichroic mirror 941, the blue light beam B included in the light beam W emitted from the illumination optical system 923 is used.
The green light flux G is reflected at a right angle, and travels toward the green reflection dichroic mirror 942.

The red light beam R passes through the blue-green reflecting dichroic mirror 941, is reflected at a right angle by the rear reflecting mirror 943, and is emitted from the emission unit 944 of the red light beam R to the prism unit 910 side. Next, of the blue and green luminous fluxes B and G reflected by the blue-green reflecting dichroic mirror 941, the green reflecting dichroic mirror 94
In 2, only the green light flux G is reflected at a right angle, and is emitted from the emission part 945 of the green light flux G to the color combining optical system side. The blue light beam B that has passed through the green reflection dichroic mirror 942 is transmitted from the light emitting system 946 of the blue light beam B to the light guide system 9.
The light is emitted to the side 27. In this example, the distances from the light emitting portion of the light beam W of the illumination optical system 923 to the light emitting portions 944, 945, and 946 of the color light beams in the color separation optical system 924 are all set to be equal.

The red and green luminous flux R of the color separation optical system 924,
Condensing lenses 951 and 952 are arranged on the emission sides of the G emission sections 944 and 945, respectively. Therefore,
The red and green luminous fluxes R and G emitted from the respective emission sections are incident on these condenser lenses 951 and 952 and are parallelized.

The red and green luminous fluxes R and G thus collimated pass through the incident-side polarizing plates 960R and 960G, enter the liquid crystal light valves 925R and 925G, are modulated, and image information corresponding to each color light is modulated. Will be added. That is, the switching of these liquid crystal light valves is controlled by driving means (not shown) according to the image information, whereby each color light passing therethrough is modulated. As such a driving means, a known means can be used as it is. On the other hand, the blue light flux B is guided to the corresponding liquid crystal light valve 925B via the light guide system 927, where it is similarly modulated according to image information. In addition, as the liquid crystal light valves 925R, 925G, and 925B of this example, for example, those using a polysilicon TFT as a switching element can be adopted.

The light guide system 927 is a light emitting section 94 for the blue light flux B.
6, a condenser lens 954 disposed on the exit side of the light-receiving element 6, an incident-side reflection mirror 971, an exit-side reflection mirror 972, an intermediate lens 973 disposed between these reflection mirrors, and disposed on the front side of the liquid crystal light valve 925B. Condensing lens 95
The blue light flux B emitted from the condenser lens 953 passes through the incident-side polarizing plate 960B, enters the liquid crystal light valve 925B, and is modulated. The length of the optical path of each color light beam, that is, the distance from the light source lamp 181 to each liquid crystal panel, is the longest for the blue light beam B, and therefore, the light amount loss of this light beam is the largest. However, by interposing the light guide system 927, the light amount loss can be suppressed.

Next, each liquid crystal light valve 925R, 92
R, G, and B light beams modulated through 5G and 925B, respectively.
Are incident on the prism unit 910 through the exit-side polarizing plates 961R, 961G, and 961B, and are synthesized there. The color image synthesized by the prism unit 910 is enlarged and projected on the projection surface 100 at a predetermined position via the projection lens 6.

(3) Structure of the Circuit Boards 11 to 14 The circuit boards 11 to 14 are for electrically controlling the drive systems of the light source lamp unit 8, the speakers 251R and 251L, and the like. As shown, it is arranged vertically along the side surface of the outer case 2, and is fixed to the inner side surface of the outer case 2 by fixing screws 15. Note that the liquid crystal light valves 925R, 925G, 9
Although not shown in FIG. 1, the circuit board for controlling 25B is disposed horizontally above the liquid crystal light valves 925R, 925G, and 925B.

As shown in FIG. 3, the circuit boards 11 to 14 are provided with a plurality of electrically conductive portions 61 at their lower ends. The location where the electrically conductive portion 61 is provided is determined according to the length of the circuit boards 11 to 14, the noise generated, and the like. As shown in FIG. 4, the electrical conduction portion 61 is formed by plating an end surface of a concave portion 61a formed at an end portion of the circuit board 11 to form a copper plating layer 61b.

More specifically, the electrically conductive portion 61 is formed by a subtractive method in the following procedure.

When a through hole for fixing a resistor, a capacitor, and the like is formed in the base material 11A having copper plating Cu on the front and back surfaces of the glass epoxy resin plate, the base material is simultaneously formed as shown in FIG. A long hole 611 extending along the cutting line L of 11A and extending over the cutting line L is formed. Then, as shown in FIG. 5B, a semicircular concave portion 612 is further formed at the end of the formed long hole 611 in the extending direction.

Next, a copper plating layer 613 is formed on the inner peripheral end face of the long hole 611 by electrolytic plating. In addition, the recess 6
The reason why 12 is formed is to cut the substrate after copper plating and to prevent the copper plating layer 613 from peeling off during cutting.

After performing the masking process on the copper plating layer 613 together with the masking process on the printed wiring portion, as shown in FIG. 5C, unnecessary portions of the copper plating are removed by etching.

Finally, when the substrate is cut along the cutting line L and divided into circuit boards 11 to 14, the long hole 611 and the copper plating layer 613 are divided as shown in FIG. Conducting portions 61 are formed on the outer peripheral ends of the circuit boards 11 to 14 so as to be exposed.

(4) Supporting Structure of Circuit Boards 11 to 14 The circuit boards 11 to 14 having such a structure are fixed to the side surfaces of the outer case 2 by the fixing screws 15 at both ends in the horizontal direction, as described above. The lower end portion is supported by the holding member 71. The holding member 71 is a band-shaped member attached to the bottom surface of the lower case 4 according to the arrangement of the circuit boards 11 to 14 in FIG. Holding member 71
Is a sponge-like elastic member 711 as shown in FIG.
The elastic member 711 is provided on the outer peripheral surface of the elastic member 711.
And a conductive sheet 712 mixed with copper, which is provided so as to wrap around. The conductive adhesives 713 and 71 are provided on the upper and lower surfaces of the holding member 71.
4 is applied.

The circuit board 1 is held by such a holding member 71.
In the case of supporting the circuit boards 1 to 14, as shown in FIG. 7, the holding members 71 are compressed and deformed to support the circuit boards 11 to 14 in a state in which the above-described electric conducting portions 61 are immersed. The electrically conductive portion 61 of the circuit boards 11 to 14 and the shield plating layer 2 a formed on the bottom surface of the lower case 4 correspond to the conductive sheet 712 of the holding member 71.
Are electrically connected via The circuit boards 11 to 14
When attaching to the outer case 2, the circuit board 1
The holding members 71 according to the arrangement of 1 to 14 in the outer case 2
Are attached, the circuit boards 11 to 14 are pressed down, and while the holding member 71 is compressed and deformed, the circuit boards 11 to 14 are fixed and fixed by the fixing screws 15.

(5) Effects of the Embodiment According to the above-described embodiment, the following effects can be obtained.

That is, since the electrically conductive portion 61 is provided at the lower end of the circuit boards 11 to 14, the electrical conductive portion 61 and the shield plating layer 2 a on the bottom surface of the outer case 2 are electrically connected via the holding member 71. Connection can be prevented, the generation and jump of noise generated on the circuit boards 11 to 14 can be prevented, and a stable circuit operation can be secured.

Further, the electrically conductive portion 61 is formed of the copper plating layer 61.
b, when the printed wiring is formed on the circuit boards 11 to 14, the electric conducting portion 61 can be formed simultaneously with the step of forming the through hole, and the electric conducting portion 61 is provided. The manufacture of the circuit boards 11 to 14 can be facilitated.

Further, since the above-described circuit board 11 is connected to the shield plating layer 2a via the conductive sheet 712 of the holding member 71, it is not necessary to provide a dedicated connection line separately on the circuit boards 11 to 14. The circuit boards 11 to 14 and the shield plating layer 2a can be easily and electrically connected.

Since the holding member 71 is made of a sponge-like elastic body, the holding member 71 is deformed according to the contact state of the circuit boards 11 to 14, and
And the holding member 71 can be reliably connected electrically. Further, since the circuit boards 11 to 14 are held by the holding member 71 having elasticity, the elasticity of the holding member 71 allows the circuit boards 11 to 14 to be held even if a fixing position of the fixing screw 15 cannot be sufficiently secured. It can be securely held and fixed inside the outer case 2 without rattling.

Since the grounding means is constituted by the shield plating layer 2a formed on the inner surface of the housing, the grounding means can be easily formed in the outer case 2, and
The grounding means can be simplified, the internal structure of the projection display 1 can be simplified, and the size of the projection display 1 can be further reduced.

(6) Modifications of the Embodiment The present invention is not limited to the above-described embodiments, but includes the following modifications.

That is, in the above-described embodiment, the plurality of electrically conductive portions 61 are provided at the lower end portions of the circuit boards 11 to 14. However, the present invention is not limited to this. Alternatively, an electrically conductive portion may be formed at the upper end.

In the above-described embodiment, the present invention is applied to the circuit boards 11 to 14 arranged vertically. However, the present invention is not limited to this, and the present invention is applied to the circuit boards arranged horizontally. Is also good.

Further, in the above-described embodiment, the electric conduction portion 61 forms the concave portion 61a in the circuit boards 11 to 14,
Although formed by forming the copper plating layer 61b on the end face of the concave portion 61a, the present invention is not limited to this, and the metal plate that is mechanically fitted to the circuit board and covers the outer peripheral end face of the circuit board is electrically connected. A conductive portion may be formed. By forming the electrical conduction portion with the metal plate in this way, the electrical conduction portion can be formed over the entire end portion of the circuit board, so that the outer peripheral end of the circuit board provided with the electrical conduction portion is provided. The electrical connection with the grounding means can be made at any position along the part.

In the above embodiment, the circuit board 1
Bonding of the holding members 71, the shield plating layer 2a, and the holding member 71 has been performed by the conductive adhesives 713, 714 applied to the entire upper surface and lower surface of the holding member 71, but is not limited thereto. Absent. That is, FIG.
As shown in (A), the adhesive is not applied to the upper surface, and the adhesive 914 having no conductivity is applied to a part of the lower surface substantially at the center in the width direction.
You may hold 1-14. In this case, as shown in FIG. 8B, when the elastic member 911 of the holding member 91 is compressed and deformed by the circuit boards 11 to 14, the widthwise end of the conductive sheet 912 of the holding member 91 is in contact with the shield plating layer 2a. And the electrical connection between them is ensured.

In the above-described embodiment, the holding member 71
Has a square cross section and is connected to the circuit boards 11 to 14 via the conductive adhesives 713 and 714, but the present invention is not limited to this, and the holding member has a groove portion narrower than the thickness dimension of the circuit board. And the circuit board may be inserted into the groove. With such a holding member, there is no need to apply an adhesive or the like to the upper surface of the holding member.

Further, in the above-described embodiment, the grounding means is the shield plating layer 2a formed on the inner surface of the outer case 2.
However, the present invention is not limited to this, and the present invention may be used by attaching a metal plate to the inner surface of the outer case and using the metal plate as a grounding means. May be used.

In the above embodiment, the circuit board 1
1 to 14 were based on the glass epoxy resin plate 11A. However, the present invention is not limited to this, and the present invention can be applied to other plastic base materials, such as ceramics and paper epoxy. However, the same effects as those described in the above embodiment can be obtained.

In the above-described embodiment, the present invention is used for the projection type display device 1. However, the present invention is not limited to this.
The present invention may be applied to other electronic devices such as a computer.

In addition, specific structures, shapes, and the like when the present invention is implemented may be other structures and the like as long as the object of the present invention can be achieved.

[0063]

According to the circuit board and the electronic device of the present invention as described above, since the electric conduction portion is provided at the outer peripheral end of the circuit board, the electric conduction portion and the grounding means inside the housing are provided. Is electrically connected, noise and static electricity generated and jumped into the circuit board can be prevented irrespective of the arrangement direction of the circuit board, and stable circuit operation can be ensured.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating an internal structure of a projection display device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining a structure of an optical system of the projection display device of the embodiment.

FIG. 3 is a front view illustrating an arrangement of an electrically conductive portion provided on a circuit board in the embodiment.

FIG. 4 is a partial front view of a circuit board showing a structure of an electric conduction portion in the embodiment.

FIG. 5 is a partial front view of a circuit board for describing a method of forming an electrically conductive portion in the embodiment.

FIG. 6 is a side view and a sectional view showing a holding member in the embodiment.

FIGS. 7A and 7B are a partial side view and a cross-sectional view illustrating a mounting structure of an electric conduction portion and a holding member of the circuit board in the embodiment.

FIG. 8 is a cross-sectional view illustrating a holding member that is a deformation of the holding member of the embodiment, and an attachment structure of the electrical conduction portion and the holding member.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electronic device (projection display device) 2 housing (exterior case) 2 a grounding means (shield plating layer) 6 projection lens 10 optical system 11 to 14 circuit board 61 electrical conduction portion 61 b metal plating layer 71, 91 holding member 81 Light source lamp 711 Elastic member 712 Conductive sheet

Claims (7)

[Claims] 1. A circuit board housed in a housing, wherein the housing prevents radiation of noise generated inside the housing and prevents external noise from jumping into the housing. A circuit board provided with a grounding means for preventing, and the circuit board is provided at an outer peripheral end thereof and provided with an electrically conductive portion electrically connected to the grounding means. 2. The circuit board according to claim 1, wherein the electrical conduction portion is constituted by a metal conduction portion formed on at least a part of the outer peripheral end. 3. An electronic apparatus comprising a housing for housing a circuit board therein, wherein said housing prevents radiation of noise generated inside said housing and said housing of external noise. Grounding means for preventing jumping into the inside; and a holding member electrically connected to the grounding means and holding the circuit board, the circuit board being provided at an outer peripheral end of the circuit board. And an electrical conduction part electrically connected to the grounding means is provided, wherein the electrical conduction part and the grounding means are electrically connected via the holding member. Electronic equipment. 4. The electronic device according to claim 3, wherein the holding member is formed of an elastic body that is deformed according to a contact state of the circuit board. 5. The electronic device according to claim 4, wherein the holding member comprises a sponge-like elastic member and a conductive sheet provided on an outer peripheral surface of the elastic member. machine. 6. The electronic device according to claim 3, wherein said grounding means is made of shield plating formed on an inner surface of said housing. . 7. An electronic apparatus according to claim 3, wherein said light source lamp is used to optically process a light beam emitted from said light source lamp to form an optical image in accordance with image information. An electronic apparatus, comprising: an optical system to be formed; and a projection lens for enlarging and projecting the optical image on a projection surface.