JPH09245986A - Static shield structure for magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a static electricity preventive structure in which appearance of a cabinet is not deteriorated, and in which installation workability is favorable. SOLUTION: A cabinet 1 is provided with a changing switch 6 inside, and an operation button 3 to operate the changing switch 6. For a conductive piece 4 disposed between the changing switch 6 and the inside of the cabinet 1, one end part of it is fixed to the cabinet 1, and it is provided with an elastic piece 40 connected to the operation button 3, and a contact piece 41 formed continuous with a tip part of the elastic piece 40 and curved as its swollen side directed toward a shield plate 2 as a grounding body. By flexure deformation of the elastic piece 40 by push pressure of the operation button 3, the contact piece 41 slides as it is in contact with the shield plate 2 under pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic shield structure for protecting an operation changeover switch in a cabinet from external static electricity in a magnetic recording / reproducing apparatus such as a video camera.

[0002]

2. Description of the Related Art In a magnetic recording / reproducing apparatus such as a video camera, as shown in FIG.
The operation buttons (3) (3) corresponding to the operation mode such as recording and reproduction are provided so as to be retractable, and the changeover switch (6) operated by each operation button (3) is provided in the cabinet (1). Therefore, from the outside of the cabinet (1), static electricity is passed through the gap between the operation button (3) and the cabinet (1), and the static electricity is transferred to the cabinet (1).
It may get inside. This static electricity is often emitted from the user's fingertip, but this static electricity is generated by the changeover switch.
(6) may malfunction. Therefore, various electrostatic shield structures for protecting the changeover switch (6) from static electricity have been conventionally proposed, for example, those shown in FIGS. 8 and 9.

In FIG. 8, a rib (10) is provided inside the cabinet (1), and a relay board (60) on the rib (10).
The change-over switch (6) is mounted on. Cabinet (1)
The changeover switch (6) is elastically deformable on the inner surface of the outer wall of the
One end of the conductive plate (8) extending so as to cover the
The operation button (3) is arranged at a position on the conductive plate (8) corresponding to the changeover switch (6). The upper end of the operation button (3) is projected and retracted from the opening (12) formed in the cabinet (1) to the upper surface of the cabinet (1). The other end of the conductive plate (8), together with a metal plate chassis (7) of a well-known mechanism deck that performs recording and reproduction via a magnetic tape, is attached to a positioning boss (11) protruding from the rib (10) with a screw (14). It is fixed in. The screw (14) is a window hole (1
Pass through 3) and screw into the positioning boss (11).

The static electricity that has entered the cabinet (1) through the gap between the opening (12) and the operation button (3) flows through the conductive plate (8) to the chassis (7). The chassis (7) is an electrostatic grounding body, and since the conductive plate (8) is grounded to the chassis (7), static electricity does not reach the changeover switch (6), and malfunction of the changeover switch (6) is prevented. Has been done. In addition, due to the arrangement of the mechanism deck and the operation button (3), if the chassis (7) and the conductive plate (8) cannot be screwed together,
As shown in FIG. 2, the conductive plate (8) and the chassis (7) are connected by an electric wire (9) to protect the changeover switch (6) from static electricity. This is the chassis (7) and conductive plate (8)
Is connected with the electric wire (9) in advance, and the electric wire (9) is housed between the cabinet (1) and the chassis (7) while
Install (7) in cabinet (1).

[0005]

In the antistatic structure shown in FIG. 8, since the window hole (13) is opened on the cabinet (1), the appearance may be impaired in appearance. Furthermore, there is a risk that the conductive plate (8) will corrode due to long-term use, the contact resistance with the chassis (7) will increase, and the conduction between the conductive plate (8) and the chassis (7) will deteriorate. . In addition, as shown in FIG. 9, the electric wire (9) is connected to the conductive plate (8) and the chassis (7), and the electric wire (9) is connected to the cabinet (1) and the chassis (7).
The cabinet (7) is stored in the cabinet while it is stored between (7).
(1) The work of mounting inside is complicated. An object of the present invention is to provide an antistatic structure that does not impair the aesthetics of the cabinet, has good workability in mounting, and prevents deterioration of conduction with the grounding body.

[0006]

[Means for Solving the Problem] Changeover switch (6) inside
On the cabinet (1) equipped with the switch (6)
An operation button (3) for operating the is provided so as to be retractable. The conductive member, which is arranged between the changeover switch (6) and the inside of the cabinet (1) and is connected to the grounding body in the cabinet (1), is formed of a conductive plate and has one end fixed to the cabinet (1). And a contact piece (41) formed at the tip of the elastic piece (40) and curved toward the grounding body. The operation button (3) is attached to the elastic piece (40), and the contact piece (41) slides while being in pressure contact with the earth body in accordance with the bending deformation of the elastic piece (40) due to the pressing of the operation button (3).

[0007]

[Operation and effect] The grounding of the conductive member to the grounding body should be done when the grounding body is installed in the cabinet (1).
The conductive member previously installed in the cabinet (1)
All you have to do is contact the ground body. Therefore, as in the conventional case, the cabinet (1) and the earth body are connected to each other by the conductive plate (8).
Installation workability is improved as compared with the configuration in which the connection is made with the electric wires (9). Further, since the conductive piece (4) is attached, it is not necessary to open the window hole (13) in the cabinet (1), and the appearance of the cabinet (1) is not spoiled. Further, as the operation button (3) is pressed, the contact piece (41) slides on the earth body while pressing it, that is, the contact piece (41) slides while generating friction with the earth body. Therefore, even if the contact portion between the contact piece (41) and the ground body is initially corroded, the corroded portion is scraped off by friction. Therefore, it is possible to prevent deterioration of conduction of the conductive member due to corrosion, and the changeover switch (6) is surely protected.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of the present invention will be described below in detail with reference to the drawings. Note that the same reference numerals are used for the same configuration as the conventional one. As shown in FIG. 1, inside the cabinet (1), a circuit board (5) having a shield plate (2) on the upper surface,
A conductive piece (4) made of phosphor bronze or the like is provided facing the upper surface of the shield plate (2). The circuit board (5) is grounded to the mechanism deck. The shield plate (2) is
It is formed by bending a tin plate, etc., and prevents high-frequency noise from entering the circuit board (5), and serves as a grounding body that contacts the conductive piece (4) as described later. In this example, the shield plate (2) is used as a grounding body in accordance with the content that the applicant is considering implementing. However, as in the conventional case, the grounding body is required for the mechanism deck chassis (7). Good.

One end of the conductive piece (4) is fixed to the inside of the cabinet (1), and the elastic piece (40) having the operation button (3) attached to the upper surface and the tip of the elastic piece (40) are attached. The contact piece (41) having its bulge directed toward the shield plate (2) is integrally provided. The lower end of the contact piece (41) is in contact with the upper surface of the shield plate (2). An operation button (3) is attached to the central portion of the elastic piece (40) in the longitudinal direction, and the upper end of the operation button (3) is freely retractable from the opening (12) formed in the cabinet (1). Put out. On the circuit board (5), on the transition path of the operation button (3), the changeover switch pushed by the operation button (3)
(6) is provided. The changeover switch (6) is for switching the drive mode of the mechanism deck as in the conventional case, and is turned on by being pushed.

In order to bring the conductive piece (4) into contact with the shield plate (2), the conductive piece (4) is mounted in the cabinet (1) in advance, and in this state, the circuit board (5) is attached to the cabinet (1). Implement in The contact piece (41) of the conductive piece (4) is pressed against the upper surface of the shield plate (2) by the elastic force of the elastic piece (40), whereby the conductive piece (4) and the shield plate (2) are electrically connected. Connected to. When the user's finger touches the operation button (3), a small amount of static electricity may enter the cabinet (1) through the gap between the opening (12) of the cabinet (1) and the operation button (3). .
In this case, the static electricity passes through the conductive piece (4) and flows to the shield plate (2). The changeover switch (6) is not affected by static electricity, and the risk of malfunction of the changeover switch (6) can be prevented.

As shown in FIG. 3, when the user pushes the operation button (3) into the cabinet (1), the elastic piece (40) rotates clockwise around the fixing portion to the inner surface of the cabinet (1). Then
The contact piece (41) is further pressed onto the shield plate (2). At this time, as shown in an enlarged view in FIG. 2B, the contact portion between the contact piece (41) and the shield plate (2) is displaced from the initial contact position b to the position a on the contact piece (41). That is, the contact piece (41)
With the elastic deformation of the elastic piece (40), the member rotates counterclockwise from the state shown in FIG. 2 (a) while being pressed against the shield plate (2).

Since the conductive piece (4) is made of phosphor bronze, its surface may corrode over a long period of time to form patina. In this case, the contact resistance with the shield plate (2) is increased, and the static electricity transmitted through the conductive piece (4) is absorbed by the shield plate (2).
Since it is not completely transmitted to (2), there is a possibility that a complete ground connection is not made and the changeover switch (6) is not sufficiently protected. In the conductive piece (4) of this example, the contact piece (41) slides with friction between the shield plate (2) and the contact piece (41) when the operation button (3) is pressed. 41) and shield plate
Even if the contact area with (2) is corroded, the corroded area is stripped off by friction. Therefore, the shield plate (2) and the conductive piece
The contact resistance of (4) does not increase and prevents deterioration of conduction of the conductive piece (4).

In this example, a circuit board is provided in the cabinet (1).
Simply attach (5) and bring the conductive piece (4) attached in the cabinet (1) into contact with the shield plate (2).
Since the static electricity that jumps toward the change-over switch (6) can be shielded, the cabinet (1) and the grounding body can be mounted as compared with the conventional structure in which the conductive plate (8) and the electric wire (9) are connected. Good workability. Also, to attach the conductive piece (4),
There is no need to open a window hole (13) in the cabinet (1), and the appearance of the cabinet (1) is not spoiled.

FIG. 4 is a view showing another example of the conductive piece (4). The contact piece (41) faces the side surface of the shield plate (2), and the operation button (3) is placed on the elastic piece (40). When the operation button (3) is pressed, the contact portion of the contact piece (41) with the shield plate (2) moves from position b to position a (see FIGS. 5A and 5B). As a result, even if the original contact portion between the contact piece (41) and the shield plate (2) is corroded, the corroded portion is peeled off by friction. In addition, as shown in FIGS. 7 and 8, the conductive piece (4) may be T-shaped, and two contact pieces (41) (41) may be provided at both ends. In this case, as the operation button (3) is pressed, each contact piece (41) presses and contacts the corresponding shield plate (2).

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope. Further, the configuration of each part of the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made within the technical scope described in the claims. For example, in this example, the shield plate (2) is made of tinplate material, but may be made of other material having good conductivity.

[Brief description of drawings]

FIG. 1 is a side view in which a part of a cabinet is cut away.

FIG. 2A is an enlarged view of the contact piece when the operation button is not operated, and FIG. 2B is an enlarged view of the contact piece when the operation button is pressed.

FIG. 3 is a side view showing a state in which an operation button is pushed in, with a part of the cabinet cut away.

FIG. 4 is a side view showing a conductive piece in another example with a cabinet cut away.

5A is an enlarged view of the contact piece when the operation button in FIG. 4 is not operated, and FIG. 5B is an enlarged view of the contact piece when the operation button is pressed.

FIG. 6 is a plan view of a conductive piece according to another example.

FIG. 7 is a side view showing the conductive piece of FIG. 6 with the cabinet cut away.

FIG. 8 is a side view showing a conventional electrostatic shield structure with a part of a cabinet cut away.

FIG. 9 is a side view showing another conventional electrostatic shield structure with a part of the cabinet cut away.

FIG. 10 is a perspective view of the cabinet.

[Explanation of symbols]

 (1) Cabinet (3) Operation button (6) Changeover switch (40) Elastic piece (41) Contact piece

Claims (1)

[Claims] 1. An operation button (3) for operating the change-over switch (6) is provided on a cabinet (1) having a change-over switch (6) inside so as to be retractable from the cabinet (1). ) And the inside of the cabinet (1) are connected to a grounding member provided inside the cabinet (1), and a switch (6) is provided for eliminating static electricity from the outside of the cabinet (1). In the electrostatic shield structure that protects, the conductive member is made of a conductive plate,
An elastic piece (40) having one end fixed to (1), and the elastic piece (40)
Contact piece formed at the tip of the and curved toward the ground
(41) and the operation button (3) is the elastic piece (40).
The electrostatic shield structure is characterized in that the contact piece (41) slides while being in pressure contact with the grounding body as the elastic piece (40) is flexibly deformed by being pressed by the operation button (3).