JPH09185101A - Two-step switching mechanism provided with waterproof function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To add a waterproof function to a two-step switching mechanism without adding a special waterproof member. SOLUTION: A release button 20 is arranged in a recessed part space constituted by arranging a printed circuit board 40 so that it may cover the entire lower surface of a cylindrical peripheral wall 12 hanging from the inner surface of a camera cover 10 so as to enclose the whole periphery of the aperture part 11 of the camera cover 10. The board 40 is provided with a photometric circuit and a release circuit. The release button has a movable armature member 30 turning on a photometric circuit at first when it is depressed, and a columnar projection 22 turning on a release circuit by pressing and deforming an elastic plate material 41 on the board 40 after turning on the photometric circuit. Annular sealing part 35 integrally formed on the member 30 is arranged between the lower end face 13 of the peripheral wall 12 hanging from the inner surface of the cover and the surface of the board 40 and constitutes a liquidtight seal there.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-step switch mechanism used for a release button of a camera or the like, and more particularly to a two-step switch mechanism having a waterproof function.

[0002]

2. Description of the Related Art Conventionally, a two-step switch has been used as a release button of a camera. In such a two-step switch, one pressing member (release button) is provided with two sets of switch mechanisms for sequentially performing opening and closing operations. That is, when the release button is pressed, first, the first switch is turned on and the photometric circuit for performing the photometric operation is closed. When the release button is pressed further, the second switch is turned on and the release circuit for releasing the shutter is closed.

On the other hand, various methods have been proposed for waterproofing a camera provided with such a two-step switch mechanism. For example, it is disclosed in Japanese Patent Laid-Open No. 58-63930. In the above, a cable release mounting screw hole formed in the release button is used, and a cover member that covers the entire movable portion of the release button is attached to that portion.

As described above, the waterproof treatment around the release button is usually performed by attaching a separate waterproof member. This causes an increase in the number of parts and the number of steps, which causes a cost increase.

[0005]

Therefore, a technical problem to be solved by the present invention is to add a waterproof function to a two-step switch mechanism without using a separate waterproof member.

[0006]

Means, Actions, and Effects for Solving the Problems The present invention was devised in order to effectively solve the above-mentioned problems. One of two sets of switch mechanisms constituting a two-stage switch is provided. A waterproof function is achieved without adding a separate waterproof member by configuring the waterproof seal member and arranging the other switch mechanism so as to surround the switch configured with the waterproof seal member. .

In the camera provided with the switch mechanism of the present invention, an opening is formed in the cover forming the outer shell of the camera, and a cylindrical peripheral wall that extends from the inner surface of the cover and surrounds the entire circumference of the opening is provided. It is preferably formed integrally with the cover. Further, a recessed space is formed by disposing a printed circuit board so as to cover the entire lower surface of the cylindrical peripheral wall, and a release button is disposed in this recessed space. As the printed circuit board, it is considered that a flexible printed circuit board having flexibility is fixed to an appropriate supporting means or a printed circuit board itself is hard.

A photometric circuit and a release circuit are provided on the printed circuit board. In addition, a movable contact member that first closes the photometric circuit when the release button is pressed is fixed on the back surface of the release button, and the photometric circuit is closed from near the center of the back surface of the release button. A pillar-shaped projection that later closes the release circuit hangs down. The protrusion extends upward from the surface of the printed circuit board to a position spaced by a predetermined distance.

The movable contact piece member includes a fixed portion, a movable contact piece, and
It is a rubber member formed by integrally molding the connection portion and the seal portion.

The fixing portion is fixed to the rear surface of the release button in a state of surrounding a columnar projection that hangs down from around the central portion thereof. Fixing is preferably performed using an adhesive or the like.

The movable contact piece has a cylindrical shape and hangs from the peripheral portion of the fixed portion so as to surround the protrusion hanging from the rear surface of the release button, and extends a predetermined distance above the surface of the printed circuit board. It extends to a spaced position. The lower end surface of the movable contact piece is annular, and at least this lower end surface is electrically conductive. That is, a conductive member may be arranged on the lower end surface of the movable contact piece, a conductive pattern may be printed, or the entire movable contact piece member including the movable contact piece may be made of conductive rubber. If the entire movable contact member is made of conductive rubber, it is advantageous in terms of cost without increasing the number of parts.

The connecting portion is a skirt-shaped member that extends along the entire circumference of the outer peripheral surface of the movable contact piece and extends obliquely downward on the outer diameter side, and connects the movable contact piece and the seal portion. ing. The skirt shape of the connection part provides a spring force that pushes the release button back to the initial position.

The seal portion is an annular member formed along the entire circumference of the outer peripheral edge portion of the skirt-shaped connecting portion, and, as will be described later, the peripheral wall hanging from the inner surface of the cover and the printed circuit board. Form a liquid tight seal in between.

When the release button of the camera constructed as described above is pressed, first, the annular lower end surface of the movable contact piece of the movable contact member comes into contact with the printed circuit board. Since the annular lower end surface is electrically conductive, as a result, the photometric circuit formed on the printed circuit board is closed. That is, the movable contact piece constitutes the first switch mechanism of the two-step switch mechanism. When the release button is further pressed, the tips of the protrusions hanging from the vicinity of the center of the back surface of the release button press the curved elastic plate made of a conductive material and elastically deformed on the surface of the printed circuit board. As a result, the back surface of the plate material contacts the printed circuit board, and the release circuit formed on the printed circuit board is closed. That is, the projections hanging from the rear surface of the release button and the plate material arranged on the front surface of the printed circuit board constitute the second switch mechanism of the two-step switch mechanism.

In the present invention, the elastic plate member is used as the second switch mechanism for closing the release circuit.
That is, at the moment when this switch mechanism is turned on, the elastic plate member is deformed, so that a good clicking feeling can be obtained, and not only the first switch but also the second switch is turned on. You can clearly recognize that.

The annular seal portion of the movable contact member is arranged between the annular lower end surface of the cylindrical peripheral wall hanging down from the inner surface of the cover and the surface of the printed circuit board to form a liquid-tight seal in the portion. That is, since the movable contact member itself that constitutes the first switch mechanism of the two-stage switch mechanism also has a function as a seal member, it is possible to achieve the seal function without adding a separate seal member. You can Further, since the second switch mechanism is arranged so as to be surrounded by the first switch mechanism having the sealing function, there is no possibility that moisture or the like may enter this portion.

The annular seal portion of the movable contact member is stably arranged between the lower end surface of the cylindrical peripheral wall and the printed circuit board.
In order to fix and achieve the sealing function, it is preferable to apply an adhesive agent between at least the lower end surface of the peripheral wall and the seal portion. However, since the seal part is made of rubber, it may be possible to adjust the distance between the lower end surface of the peripheral wall and the printed circuit board so that the seal part is sandwiched between the two in such a case. Eliminates the need for adhesives.

[0018]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view showing the main part of the two-step switch mechanism of the present invention. A circular opening 11 for arranging a release button 20 is formed in a cover 10 that constitutes the outer shell of the camera. A cylindrical peripheral wall 12 that surrounds the entire periphery of the opening 11 is integrally formed on the inner surface of the cover 10. The peripheral wall 12 is formed so as to surround a position slightly spaced from the peripheral edge of the opening 11 on the outer peripheral side. On the other hand, a flexible printed circuit board (hereinafter referred to as FP circuit board) 40 is fixed to a camera body (not shown) housed in the cover 10 by an appropriate method, and the FP circuit board 40 has a peripheral wall.
It is arranged so as to cover the entire bottom surface of twelve.

As described above, the opening provided in the cover 10
A recess space is formed by 11, the peripheral wall 12 hanging from the inner surface of the cover, and the FP circuit board 40 closing the lower surface of the peripheral wall, and the release button 20 is disposed in the recess space. It should be noted that, between the lower end surface 13 of the peripheral wall 12 and the surface of the FP circuit board 40, as will be described later, a sealing portion of the movable contact piece member 30.
35 are arranged so as to be sandwiched and form a liquid-tight seal.

The release button 20 is a dome-shaped member, and a columnar projection 22 that hangs down from the center is integrally formed on the back surface of the release button 20. The protrusion extends upward from the surface of the FP circuit board 40 to a position spaced by a predetermined distance.
An elastic plate member 41 made of a conductive material is arranged at a position on the FP circuit board 40 facing the tip 23 of the protrusion 22.
The function of the plate material 41 will be described later. On the other hand, the movable contact piece member 30 surrounds the protrusion 22 so that the release button 20
It is fixed on the back of the. The movable contact member is fixed by using an adhesive, and an adhesive groove 25 for pouring the adhesive is formed on the back surface of the release button.

The movable contact piece member 30 includes a fixed portion 31 and a movable contact piece 3.
2, a rubber member formed by integrally molding the connecting portion 34 and the seal portion 35.

The fixed portion 31 is fixed to the rear surface of the release button so as to surround the projection 22 that hangs from the release button.

The movable contact piece 32 has a tubular shape, and is hung from the peripheral edge of the fixed portion so as to surround the projection 22 inside.
It extends above the surface of the P circuit board 40 to a position spaced by a predetermined distance. The lower end surface 33 of the movable contact piece 32 is annular and at least this portion is electrically conductive.

The connecting portion 34 has a skirt shape and extends along the entire outer peripheral surface of the movable contact piece 32 and extends obliquely downward on the outer diameter side.

The seal portion 35 is an annular member formed over the entire outer peripheral edge of the skirt-shaped connecting portion 34,
An annular lower end surface 13 of the cylindrical peripheral wall 12 hanging from the inner surface of the cover and the F
It is arranged between the surface of the P circuit board 40 and a liquid-tight seal.

In the release button constructed as described above, the movable contact piece 32 of the movable contact piece member 30 constitutes the first switch mechanism, and the projection 22 hanging from the rear surface of the release button is the second switch mechanism. And functions as a two-stage switch mechanism as a whole. The details will be described below.

FIG. 1 shows the release button 20 in the initial position. When the pressing portion 21 of the release button 20 is pressed from here, the skirt-shaped connecting portion 34 of the movable contact piece member 30 is elastically deformed and the movable contact member 30 is moved. The piece 32 moves downward. Then, the lower end surface 33 of the movable contact piece comes into contact with the surface of the FP circuit board 40 to be in the state shown in FIG.

On the upper surface of the FP circuit board 40, as shown in FIG. 4, a conductive pattern in which two Y-shaped conductive portions 43 and 44 are arranged with their heads facing each other is printed. Has been done. 1 to 3, the head end surface 44a of the conductive portion 44 appears. This conductive pattern constitutes a photometric circuit that performs a photometric operation. On the other hand, an annular region 42 shown by a broken line in FIG. 4 is a region where the lower end surface 33 of the movable contact piece 32 contacts in the state of FIG. Since the movable contact piece member 30 is entirely made of conductive rubber, the lower end surface of the movable contact piece 32 is
When 33 comes into contact with the annular region 42 on the FP circuit board 40, the two conductive parts 43 and 44 are connected to each other and become conductive. That is, the photometric circuit is closed and the photometric operation is performed. In order to close the photometric circuit, it is sufficient if at least the lower end surface of the movable contact piece 32 is electrically conductive, so that the entire movable contact piece member is made of insulating rubber and a conductive pattern is printed on the lower surface thereof. ,
You may fix a conductive material separately.

In this way, the lower end surface 33 of the rubber movable contact piece 32 is
The conductive pattern printed on the FP circuit board 40 and the conductive pattern printed on the FP circuit board 40 respectively constitute a switch piece related to the first switch (such a switch is hereinafter referred to as a rubber SW).

When the release button 20 is pushed further from the state shown in FIG. 2, the movable contact piece 32 and the skirt-shaped connecting portion 34 are elastically deformed, and the tip portion 23 of the protrusion 22 hanging from the rear surface of the release button is placed on the FP circuit board 40. The arranged plate member 41 is pressed to bend (elastically deform). Then, the back surface of the plate material and the front surface of the FP circuit board come into contact with each other to be in the state shown in FIG. A predetermined conductive pattern (not shown) that constitutes a release circuit for releasing the shutter is printed on the back surface of the FP circuit board (the surface on the lower side in FIG. 1), and a part of the conductive pattern is on the upper surface of the FP circuit board. It extends to a position below the plate and is interrupted at this position. Since the plate material is made of a conductive material, when the plate material bends and its back surface comes into contact with the front surface of the FP circuit board, the conductive patterns are connected to each other and become conductive. That is, the release circuit is closed and the shutter is released.

Thus, the plate material 41 arranged on the FP circuit board 40 and the conductive pattern printed on the FP circuit board 40 are
Each constitutes a switch piece related to the second switch. The plate member 41 is formed by bending a flat plate-shaped conductive member into a predetermined shape, and when the release circuit is closed, the plate member 41 is elastically deformed and "clicks".
It gives a good click feeling (such a switch is called a diaphragm SW hereinafter). The diaphragm SW is closed by bringing the back surface of the plate material 41 into contact with the front surface of the FP circuit board 40. That is, FIG.
In, the rubber SW is in a closed state, but the diaphragm SW is not yet closed.

In the two-step switch mechanism configured as described above, the movable contact piece member 30 forming the rubber SW also has a function as a seal member. That is, the seal portion 35 of the movable contact member 30 constitutes a liquid-tight seal between the peripheral wall lower end surface 13 hanging from the inner surface of the cover and the FP circuit board 40, and moisture, dust, etc. enter the camera from the portion. To prevent it. Further, since the connecting portion 34 connecting the movable contact piece 32 and the seal portion 35 also extends over the entire circumference of the outer peripheral surface of the movable contact piece 32, the space between the movable contact piece member 30 and the FP circuit board 40. It is also possible to prevent moisture, dust, and the like from entering the inside (that is, the space where the diaphragm SW is arranged). In addition, in FIGS. 1 to 3, the seal portion 35 of the movable contact piece member 30.
Is used to achieve a sealing function by being fixed to the lower end surface 13 of the peripheral wall of the cover 10 using an adhesive, and an adhesive groove 14 for pouring the adhesive is formed in the lower end surface 13 of the peripheral wall. However, since the seal portion 35 is made of rubber, the distance between the lower end surface 13 of the peripheral wall of the cover 10 and the FP circuit board 40 is adjusted, and the seal portion 35 of the movable contact piece member 30 is sandwiched between them in a compressed state. It is also possible to have such a configuration. In this case, the sealing function can be achieved without using an adhesive or the like.

Further, the movable contact piece member 30 gives a spring force for returning the release button 20 after being pressed to the initial position. That is, FIG. 3 shows the state where the release button 20 is pushed deepest, but when the release button 20 is released from this state, the release button 20 is released due to the restoring force of the elastically deformable movable contact piece 32 and the connection portion 34. It returns to the state shown in FIG. Furthermore, from that state, the connection part
The restoring force of 34 causes the release button 20 to return to the initial state shown in FIG. When the release button 20 returns from the position shown in FIG. 3 to the position shown in FIG. 2, the restoring force of the elastically deformed plate material 41 also contributes to the return of the release button 20. The connection portion 34 has a skirt-like shape in order to effectively give such a restoring force.

As described above, in the present invention, it is not necessary to separately provide a spring or the like for returning the release button from the depressed position to the initial position.

An annular retaining portion 24 is provided on the peripheral portion of the release button 20. The retaining portion 24 is provided on the cover 10
The release button 20 is prevented from coming off by coming into contact with the back surface of the peripheral edge portion 15 of the opening portion 10 formed in.

[Brief description of the drawings]

FIG. 1 is a sectional view of an essential part showing a two-step switch mechanism of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a release button is pressed and a rubber SW is turned on from the state of FIG.

FIG. 3 is a cross-sectional view showing a state where the diaphragm SW is turned on by further pressing the release button from the state of FIG.

FIG. 4 is a plan view showing a conductive pattern of the rubber SW of FIG.

[Explanation of symbols]

 10 Cover 11 Opening 12 Circumferential wall 13 Bottom edge of peripheral wall 14 Adhesive groove 15 Edge of opening 20 Release button 21 Pressing portion 22 Protrusion 23 Tip of protrusion 24 Retaining portion 25 Adhesive groove 30 Moving contact member 31 Fixed portion 32 Movable contact piece 33 Lower end surface of the movable contact piece 34 Connection part 35 Seal part 40 FP circuit board 41 Plate material 42 Annular area 43, 44 Conductive part

Claims (3)

[Claims] 1. A cylindrical peripheral wall (12) which surrounds the entire circumference of an opening (11) provided in a camera cover (10) and hangs down from the inner surface of the cover, and the entire lower surface of the peripheral wall (12) is formed. A switch mechanism in which a release button (20) is arranged in a recessed space formed by arranging the printed circuit board (40) so that the printed circuit board (40) includes a photometric circuit and a release circuit. A circuit is provided, and on the back of the release button (20), the movable contact piece member (30) that closes the photometric circuit first when the release button is pressed is fixed, and from the vicinity of the center part. The surface of the printed circuit board (40) has columnar protrusions (22) that close the release circuit by pressing and deforming the elastic plate material (41) on the printed circuit board (40) after the photometric circuit is closed. Is hung down to a position separated by a predetermined distance from Contact piece member (30) is a release button in a state surrounding the columnar projection (22) (20) fixing portion fixed to the rear surface (31),
A cylinder that hangs from the peripheral portion of the fixed portion (31) to a position spaced a predetermined distance from the surface of the printed circuit board (40) so as to surround the protrusion (22) and has a conductive lower end surface (33). -Shaped movable contact piece (32), a skirt-shaped connecting portion (34) extending along the entire circumference of the outer peripheral surface of the movable contact piece (32) and extending obliquely downward on the outer diameter side, and a connecting portion (34 ) Is a rubber member integrally formed with an annular seal portion (35) formed along the outer peripheral edge portion of the movable contact piece member (30), and the annular seal portion (35) is a cover. The lower end surface (13) of the cylindrical peripheral wall (12) hanging from the inner surface and the printed circuit board
A two-stage switch mechanism, characterized in that it is arranged between the surface of (40) and a liquid-tight seal in that portion. 2. The two-step switch mechanism according to claim 1, wherein the movable contact member (30) is entirely made of conductive rubber. 3. An annular seal portion (3) of the movable contact member (30).
5) is the lower end surface (13) of the cylindrical peripheral wall (12) and the printed circuit board (40).
The two-stage switch mechanism according to claim 1 or 2, wherein the two-stage switch mechanism is arranged in a compressed state between the two-stage switch mechanism and the surface.