JPS63287936A - Device for opening/closing rear cover of camera - Google Patents

Abstract

PURPOSE:To facilitate the opening/closing of a rear cover by forcedly driving the rear cover from a half-open position to a full-open position with the aid of mechanical power. CONSTITUTION:As soon as a locking lever 9 turns clockwise from a specified position, the lock of the contact piece of a switch 17 is released from the lever 9 and the switch 17 goes to ON, then an energizing circuit for shape memory alloy is completed so that the shape memory alloy generates heat and the total length is rapidly contracted at a specified temperature so as to move a movable member 6. And the lever 9 supported by the member 6 moves left and the rear cover 1 locked with the lever 9 is drawn left and then the projecting parts 1c and 1d of the rear cover 1 are strongly pushed into the grooves 2a and 3a of the camera main body so as to crush packing 4 and 5 in the grooves. When the member 6 moves, the hooking part 25a of the lever 25 is locked with the back end surface of the member 6 with the aid of the force of a spring 27 and the rear cover 1 is locked in the full-open state by the lever 25.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a camera back cover opening/closing device, and more particularly to a camera back cover opening/closing device configured so that the back cover can be closed without manual operation. In particular, the present invention relates to a camera back cover opening/closing device suitable as a back cover opening/closing device of a waterproof camera.

[Background of the Invention] In a waterproof camera or an underwater camera, a rubber waterproof backing is provided along the edge of the opening for the back cover of the camera, and when the back cover is closed, the back cover closes the waterproof backing. The opening/closing opening is made waterproof by crushing the backing. Therefore, the known waterproof camera has the disadvantage that it is difficult to close the back cover because a very large force is required to close the back cover.

[Object of the Invention] An object of the present invention is to provide a back cover opening/closing device that allows the back cover to be opened and closed much more easily than known waterproof cameras.

[Summary of the Invention] The back cover opening/closing device according to the present invention is characterized by having a drive means for forcibly driving the back cover from a half-open position to a fully closed position by mechanical power. In the back cover opening/closing device of the invention, the back cover can be opened and closed easily without requiring much force. In addition, in the embodiments of the present invention shown below, the driving means has a power generating member made of a shape memory alloy, so the driving means is small, and therefore, the closing operation of the back cover is configured to be performed by power. Even if this is done, there is no risk of the camera becoming larger.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the accompanying drawings.

1 and 2 are views showing the mechanical structure of the back cover opening/closing device in a waterproof camera equipped with the back cover opening/closing device according to the present invention, and FIG. 1 shows the mechanical structure of the back cover opening/closing device. FIG. 2 shows a state in which the back cover 1 is closed.

In FIGS. 1 and 2, 2 and 3 are camera bodies (not shown), and 1 is a back cover. The inner surface of the back M1 is provided with a protruding portion having a hook portion 1a at approximately the center thereof, and the recessed portion 2a of the camera body Z&3 is provided at the peripheral edge of the inner surface over the entire circumference of the back N1. and 3a are formed with protrusions 1c and 1d that can be fitted into them. Recesses 2a and 3a formed around the back cover opening of the camera body house rubber backings 4 and 5 that are crushed when pressed.

In FIGS. 1 and 2, a plate-shaped movable member 6 that can move in the left-right direction (that is, in the front-back direction of the camera) is arranged in the back cover opening of the camera body. 6 is always urged rightward by a spring 16. The movable member 6 has elongated holes 6a and 6b extending in the left-right direction in FIGS. The movable member 6 is inserted into the holes 6B and 6b so as to be movable relative to each other, and is supported and guided by the bins and 8 so as to be movable in the left-right direction.

A bottle 10 is protruded from approximately the center of the movable member 6, and a locking lever 9 for locking the spine M1 is rotatably supported on the bottle 10, and the locking lever 9 is supported by a spring. 11 constantly applies a clockwise rotational force about the bottle 10. At one end of the locking lever 9, there is a hook portion 1 on the back M1.
A hook portion 9a is formed to engage with the hook portion 9a.
A bottle 9b is provided protruding from one side surface (the surface corresponding to the back side of the page in FIGS. 1 and 2).

An unlocked state holding lever 12 for holding the bin 9b and the hook part 9a of the engagement lever 9 at a position away from the hook part 1a of the back cover 1 is rotatable by the protruding bin 13 of the movable member 6. The lever 12 is always urged clockwise about the bottle 13 by a spring 14.

When the holding lever 12 is in the state shown in FIG. Hook part 9a on back M1 hook part 1
It is pushed up above the position where it can engage with a. The holding lever 12 is also formed with a vertically bent portion 12a that can engage with the tip end surface 1b of the protruding portion of the back M1. When the holding lever 12 and the bottle 9b are held together, the holding lever 12 and the bottle 9b are disengaged.

A switch 17 operated by the hook portion 9a of the locking lever 9 is attached to the movable member 6.
is opened when the hook portion 9a of the locking lever 9 is in the state shown in FIG. 1, and when the hook portion 9a of the locking lever 9 is engaged with the hook portion 1a of the back M1 as shown in FIG. Closed.

Three rotatable rollers 22 to 24 are provided on the front end side of the movable member 6 (the left end in FIGS. 1 and 2), and are arranged at a predetermined interval in front of the movable member 6. The fixed plate 19 also has two rotatable rollers 20 and 2.
1 is provided. And these rollers 20-2
4, a shape memory alloy 18 in the form of an elongated body is wound in a zigzag shape, and both ends of the shape memory alloy 18 are fixed to a fixing plate 19 and connected to an electric circuit shown in FIG. 3, which will be explained later. The connected shape memory alloy 18 serves as a power generating means for driving the movable member 6 to the left in FIG. 6 of the driving means.

A lever 25 extending parallel to the moving direction of the movable member 6 is disposed above the movable member 6, and the lever 25 is connected to the first lever 25.
It is rotatably supported by a fixed bin 26 that is perpendicular to the plane of the drawing, and biased clockwise around the bin 26 by a spring 27. A hook portion 25a that can be engaged with the rear end surface of the movable member 6 is formed at one end of the lever 25 (the end located on the back side of the camera), and the other end of the lever 25 is formed between the movable member 6 and the fixed plate 19. It extends to a position where it can engage with a lever 29, which will be described later, arranged between the two. This lever 25 is
It has a function of locking the back cover 1 in the fully closed position via the locking lever 9 by locking the movable member 6 when the movable member 6 moves forward most, that is, the movable member 6BL It constitutes a locking means for the locking lever 9 and the back M1.

Above the lever 25, there is a hook portion 25a of the lever 25.
A switch 28 is arranged, which is operated by vertical movement of the
The switch 28 and the switch 17 are incorporated into an energizing circuit for heating the shape memory alloy 18. In the state shown in FIG. 1, the switch 28 is closed, and
In the state shown in FIG. 2, switch 28 is open.

A back cover opening operation member 29 extending in the vertical direction is disposed at a position between the movable member 6 and the fixed plate 19, and the operation member 2
9 is always urged upward by a spring 32. A knob 29e that is operated by the pad of a person's finger is protruded from the side surface near the lower end of the operating member 29.
9e projects to the outside of the camera through a vertically long hole formed through the outer case of the camera.

A pin 29c that can be engaged with the front end of the lever 25 and a pin 29d that can be engaged with the front end of the locking lever 9 are protruded from the side surface of the operating member 29. When the operating member 29 is operated in a downward direction, the bin 29c pushes down the front end of the lever 25 and the bin 29d
is adapted to push down the front end of the locking lever 9.

Vertical holes 29a and 29b are provided through the operating member 29, and fixing bins 30 and 3 protruding from the camera body are provided through the operating member 29.
1 is inserted into the holes 29a and 29b so as to be relatively slidable,
The operating member 29 can be moved up and down by being guided by the bins 3° and 31.

A protrusion 2 protruding rearward at the lower end of the operating member 29
9f is formed, and a switch 33 operated by the protrusion 29f is disposed in the camera close to the protrusion. This switch 33 is incorporated in the current supply circuit together with the switches 17 and 25, and is turned on in the state shown in FIG. 1 and turned off in the state shown in FIG. 2.

FIG. 3 shows an energizing circuit for generating power in the elongated body 18 as a power generating means. In this energizing circuit, the elongated body 18, the switches 17 and 28, and the switches 17 and 28 are connected to the power source 34. 33 are connected in series. The state shown in FIG. 3 corresponds to the state in which the back cover 1 is opened as shown in FIG.

Next, the operation of each part of the back cover opening/closing device of the present invention will be explained with reference to FIGS. 1 to 3.

After loading the cartridge into the cartridge chamber of the camera body (not shown), press the back M1 to the left in Figure 'M1.
The distal end surface 1b of the protruding portion 1 pushes the vertically bent portion 12a of the unlocked state holding lever 12, so that the lever 12 is rotated counterclockwise about the bottle 13 by the force of the spring 14. As a result, the engagement between the tip 12b of the lever 12 and the pin 9b of the locking lever 9 is released, and the lever 9 is rotated clockwise about the pin 10 by the force of the spring 11. Therefore, the hook portion 9a of the lever 9 engages with the hook portion 1a of the back cover 1, and the back M1 is locked by the lever 9 so that it cannot move in the back cover listening direction. In addition, at this time, the protrusions 1c and 1d on the inner surface of the back M1 are aligned with the groove 2a of the camera body.
and 3a, but the gaskets 4 and 5 have not yet been crushed by the protrusions 1c and 1d.

On the other hand, as the locking lever 9 rotates clockwise from the position shown in FIG. 1 as described above, the contact piece of the switch 17 disengages from the lever 9, so the switch 17 is turned on, and as shown in FIG. In this step, the current supply circuit for the shape memory alloy 18 is completed and the shape memory alloy 18 generates heat. For this reason, the shape memory alloy 18 rapidly shrinks in total length at a predetermined temperature,
As a result, the movable member 6 is moved from the position shown in FIG. 1 to the position shown in FIG. Therefore, the locking lever 9 supported by the movable member 6 also moves to the left (that is, toward the inside of the camera).
, the back cover 1 locked by the locking lever 9 is also pulled to the left (that is, toward the front of the camera), and the back cover 1 is
The protrusions IC and 1d are strongly pushed into the grooves 2a and 3a of the camera body, and the gaskets 4 and 5 in the grooves are pushed into the protrusion 1.
c and 1d (see Figure 2).

When the movable member 6 moves eight times from the position shown in FIG. 1 to the position shown in FIG. As a result, the movable member 6, the locking lever 9, and the back cover 1 cannot move from the position shown in FIG. is locked in a fully closed state by lever 25.

On the other hand, when the hook portion 25a of the lever 25 engages with the rear end surface of the movable member 6, the hook portion 25a and the contact piece of the switch 28 are disengaged, so the switch 28 is turned off and '! In the circuit of Figure J3, switch 28 is opened.

Therefore, since the current to the shape memory alloy 18 is cut off, the shape memory alloy 18 stretches to its original length, but at this time, no force acts between the fixed plate 19 and the movable member 6, so the movable member 6 is held in the position shown in FIG.

When opening the back M1, the camera user moves the knob 29e of the back cover opening operating member 29 downward with his/her finger, and then the operating member 29 is moved downward from the position shown in FIG. In order to push down the front end of the lever 25, the lever 25 is rotated counterclockwise in FIG. It comes off. Also, at almost the same time, the pin 29d of the operating member 29 pushes down the front end of the locking lever 9, so that the hook portion 9a of the locking lever 9 is also pushed down.
It rises from the position shown in Figure s2 and is released from being locked to the back cover 1. As a result, the movable member 6 is moved toward the rear of the camera by the force of the spring 16 and returned to the position shown in FIG. In this case, since the shape memory alloy 18 is in a slack state, the movable member 6 can move without receiving any resistance from the shape memory alloy 18.

Further, when the hook portion 9a of the locking lever 9 and the hook portion 25a of the lever 25 rise from the position shown in FIG. 2, the switch 17 is turned off and the switch 28 is turned on. On the other hand, as the operating member 29 is lowered from the position shown in FIG.
3 will be opened. Therefore, the current supply to the shape memory alloy 18 is maintained in a cut off state.

As described above, by lowering the back cover opening operation member 29, the movable member 6 returns from the position shown in FIG. 2 to the position shown in FIG. 1, and the locking of the back M1 by the locking lever 9 is released. can be opened. Even when the movable member 6 returns to the position shown in FIG. 1, the back cover itself is not pushed, but the back M1 is pushed backward by the restoring force of the gaskets 4 and 5.
When the locking of the back cover 1 by the locking lever 9 is released, the back N
1 will be opened. When the back Ml is opened and the protrusions 1c and 1d of the back cover 1 escape from the grooves 2a and 3a of the camera body, the vertically bent portion 12a of the unlocked state holding lever 12 is held by the tip surface 1b of the protrusion of the back cover 1. The lever 12 is moved to the first position by the force of the spring 14.
As a result, the pin 9b of the locking lever 9 is returned to the position shown in the figure.
is locked to the distal end surface 12b of the lever 12, and the locking lever 9 is held in the unlatched state by the lever 12 again as shown in FIG.

Since the back cover interrogation operation member 29 is always urged upward by the spring 32, the above-mentioned back cover opening operation is caused by pressing down the knob 29 with a finger. After that, when the finger is released from the knob 29e, the operating member 29 immediately returns to its original position as shown in FIG. The embodiments shown above show the case where the present invention is applied to a camera back cover opening/closing device, but the device of the present invention may also be applied to a battery compartment opening/closing device of a camera, etc. good.

[Effects of the Invention] As explained above, the device of the present invention is configured to lock the back cover so that it cannot be opened after the back cover is closed by power, so there is no need to press with a large force when closing the back cover. This makes it easy to close the back cover, especially in waterproof cameras.

Furthermore, since a shape memory alloy is used as the power generating means, the power generating mechanism and the back cover drive mechanism do not become large, and therefore the camera does not become large. Moreover, since the shape memory alloy is energized only when the back cover is closed, there is an advantage that power consumption is small and economical.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the back lid open state in one embodiment of the back lid opening/closing device according to the present invention, FIG. 2 is a diagram showing the back lid closed state in the embodiment, and FIG. 3 is a diagram showing the back lid closed state in the embodiment. It is a diagram showing a part of an electric circuit. 1...Back M 2 and 3...Camera body 4 and 5...Waterproof gasket 6...Movable member 7 and 8...Bin 9...
- Locking lever 9b... Pin 12... Unlocked state holding lever 15... Stopper 17... Switch 18
...Shape memory alloy 19...Fixing plate 20-24
...Roller 25...Lever 28...Switch 29...Back cover opening operation member 29e...
・Knob 29c and 29d...Pins 30 and 31...Bin Fig. 1

Claims (2)

[Claims] (1) It has a drive means that forcibly drives the back cover from a half-open position to a fully closed position in response to an operation to close the back cover, and the drive means is made of a material such as a shape memory alloy. 1. A back cover opening/closing device for a camera, comprising: a power generating means, the power generating means being connected to an energizing means for heating the power generating means. (2) A movable member that can move between a first position corresponding to the back cover open position and a second position corresponding to the back cover fully closed position, and the movable member is always urged toward the first position. a biasing means that is carried by the movable member and is movable between the first position and the second position, and that biases the back cover in the first position when the back cover is closed. A locking member that continues to lock the back cover even when the back cover is fully closed after locking the lid, and a driving means that drives the movable member from the first position to the second position. , a locking means for locking the movable member in the second position, and a locking means for unlocking the movable member by the locking means and the back cover by the locking member in response to an operation intended to open the back cover. a locking prevention member that holds the locking member in a position where it is not locked to the back cover when the back cover is not closed;
A back cover opening/closing device for a camera, characterized in that the driving means comprises a power generating means made of a material such as a shape memory alloy, and an energizing means for energizing the power generating means. .