JPH0367432A - Timer device - Google Patents

Abstract

PURPOSE:To simplify and miniaturize a structure by operating a self-timer via a hooking member and a hooked member with a shape memory alloy as an actuator, and returning the shape alloy by excitation after a preset time elapses. CONSTITUTION:A shape memory alloy 8 is deformed against the elastic force of a hooking spring 7, and a self-timer operating member 12 is operated by a movable contact 9 via a hooking member 6 and a hooked member 3. Excitation is performed by the contact 9 and a fixed contact 11, on/off operations of a transistor are controlled via a capacitor, the alloy 8 is excited after the preset time elapses, the alloy 8 is returned to the original shape, the hooking of the member 3 by the hooking member 6 rotated by the exciting force of the spring 7 is released, a shutter is operated during this time, and a self-timer action is performed. The shape alloy is used as an actuator instead of an electromagnet or a spring, thus a simple, small-sized and economical timer device with little power consumption is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a timer device that performs a predetermined mechanical work to the outside after a predetermined period of time has elapsed.

[Conventional technology]

Conventional timer devices of this type include: (a) one that uses an electronic circuit as a means to detect the passage of time, and an actuator that uses electromagnetic force as a means to perform mechanical work after a predetermined period of time has elapsed; (b) A spring mechanism was used as a means for detecting the passage of time and as a means for performing mechanical work after a predetermined period of time had elapsed.

[Problem to be solved by the invention]

However, the timer device (a) has problems in that it is expensive and requires a relatively high voltage.

Furthermore, the timer device (b) has problems in that it is expensive and occupies a large space.

The present invention has been made in view of these circumstances, and has a simple structure that does not require expensive parts and can reduce manufacturing costs. It can also be operated at a very low voltage and occupies less space. The purpose of the present invention is to provide a timer device that can make the timer extremely small.

[Means to solve the problem]

The timer device according to the present invention includes a locked member movable between a predetermined standby position and a predetermined release position, and a drive spring means for biasing the locked member from the standby position toward the release position. a locking member movable between a locking position where the locked member is locked in the standby position and a locking release position where the locking is released; and a locking member that applies a shape recovery force to the locking member. a shape memory alloy that acts in a direction to move the locking member toward the unlocked position; a drive circuit that energizes the shape memory alloy; and a drive circuit that turns on the drive circuit after a predetermined time has elapsed after receiving a predetermined input. and a delay circuit that causes the drive circuit to energize the shape memory alloy.

[Effect]

In the present invention, when the locked member is moved to the standby position against the drive spring and the locked member is locked to the locking member at that position, elastic energy is stored in the drive spring. Become. Next, when a predetermined input is given to the delay circuit in this state, the delay circuit turns on the drive circuit after a predetermined time has elapsed, the drive circuit energizes the shape memory alloy, and heats the shape memory alloy to a predetermined temperature range. . Then, the shape memory alloy generates a shape restoring force due to the shape memory effect, and this shape restoring force moves the locking member to the locking release position, thereby releasing the locking of the locked member by the locking member. As a result, the elastic energy stored in the drive spring is released, and the locked member is driven by the force of the drive spring. Therefore, after a predetermined time has elapsed after a predetermined input is given to the delay circuit, mechanical work can be performed on the outside via the locked member by the force of the drive spring.

〔Example〕

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

1 to 7 show an embodiment of the present invention, in which the present invention is applied to a self-timer device for a disposable camera.

1 to 6, a rotating shaft 1 is rotatably supported by a body 2 of a disposable camera, and this rotating shaft 1 is connected to a shutter mechanism (not shown) and a film winding mechanism (not shown) of the camera via a conventionally known mechanism. is linked to. A locked member 3 is fixed to the rotating shaft 1, and the locked member 3 has a locked claw 3a and a contact pressing claw 3b at positions that are 180 degrees apart from each other. The locked member 3
, and thus the rotation shaft 1 is biased counterclockwise in FIGS. 1, 3, and 5 by a torsion spring 4 (see FIGS. 2, 4, and 6). "
When we say "clockwise" and "counterclockwise" we are referring to FIGS. 1, 3 and 5).

A lever-shaped locking member 6 having a hook portion 6a at one end is supported on a rotating shaft 5 attached to the body 2 so as to be rotatable about the rotating shaft 5. The locking member 6 is biased counterclockwise by a locking spring 7 toward the positions shown in FIGS. 1, 3, and 5 (this position is the locking position of the locking member 6 in this embodiment). has been done.

One end of a wire-shaped shape memory alloy 8 made of a Ti-Ni alloy is attached to the other end of the locking member 6, and the other end of this shape memory alloy 8 is attached to the body 2. It is being Here, the shape memory alloy 8 is
A predetermined length shorter than the states shown in FIGS. 1, 3, and 5 is memorized, and when the shape memory alloy 8 contracts in an attempt to return to the memorized length, as shown by the dashed line in FIG. Thus, the locking member 6 is rotated clockwise against the locking spring 7.

One end of an elongated rectangular movable contact 9 made of a material with high springiness is attached to the body 2, and the other end of the movable contact 9 is a free end. The body 2 has first fixed contacts 10 on both sides of the movable contact 9.
and a second fixed contact 11 are attached. 12
is a self-timer operating member made of plastic,
It has a thin bar-shaped spring portion 12a and a button portion 12b integrally provided at one end of the spring portion 12m.

The other end of the spring portion 12a is fixed to the body 2, and the button portion 12b is connected to the second fixed contact 11 from the movable contact 9.
and is located closer to the free end of the movable contact 9 than the second fixed contact 11 .

A locking claw 12c is provided at the bottom end of the button portion 2b.
is integrally provided and protrudes toward the movable contact 9 side. The button portion 12b is in contact with a guide wall 13 fixed to the body 2 on the surface opposite to the locking claw 12c, and the button portion 12b is configured to move up and down along the guide wall 13. .

FIG. 7 shows the delay circuit and drive circuit in this embodiment. The second fixed contact 11 is connected to the anode of the battery 14. The movable contact 9 is connected to one end of the shape memory alloy 8, the emitter of the transistor 15, and one end of the capacitor 16.

The first fixed contact 10 is the base of the transistor 15,
It is connected to the other end of the capacitor 16 and one end of the resistor 17. The other end of the shape memory alloy 8 is connected to the transistor 1
The collector of transistor 8 and the collector of transistor 15 are connected to the base of transistor 18, respectively. The other end of resistor 17 and the emitter of transistor 18 are connected to battery 1.
It is connected to the cathode of 4.

Next, the usage and operation of this embodiment will be explained.

When the film is not wound up, the locked member 3 is in the position shown in FIGS. 1 and 2 (this position is the released position of the locked member 3 in this embodiment), and in this state, The movable contact 9 is in contact with the first fixed contact 10 due to its elasticity. For this reason, the battery 14
No current flows through the shape memory alloy 8.

Next, when the film is wound up, the rotating shaft 1 is rotated clockwise together with the locked member 3 against the drive spring 4, and the locked member 3 is moved to the position shown in FIGS. This position is the standby position of the locked member 3 in this embodiment). Then, the locked claw 3a is engaged with the hook portion 6a of the locking member 6, so that the locking member 6 locks the locked member 3 in that position, and the locking member 6 is The movable contact pressing claw 3b presses the tip of the movable contact 9. As a result, the button portion 1 of the self-timer operating member 12
A part of the side surface of the movable contact 9 is pressed against the side of the locking pawl 12c of 2b (at this time, the guide wall 13 prevents the button portion 12b from moving downward in FIG. 3 together with the movable contact 9). ), but the movable contact 9 is still in contact with the first fixed contact 10. Therefore, battery 14
No current flows through the shape memory alloy 8.

Next, when the button part 12b of the self-timer operating member 12 is pushed down against the spring part 12a as shown in FIG. It comes off the side of the locking pawl 12c, moves in a direction away from the first fixed contact 10 as shown in FIG. 5, and comes into contact with a portion of the button portion 12b above the locking pawl 12c. Further, even if the finger is released from the button part 12b thereafter, the upper end of the locking pawl 12c remains caught on the lower end of the movable contact 9 as shown in FIGS. 5 and 6 due to the elasticity of the spring part 12a. , the button portion 12b is maintained in a depressed state.

In this state, since the contact point between the movable contact 9 and the button part 12b moves away from the first fixed contact 10, the fifth
As shown in the figure, the movable contact 9 is spaced apart from the first fixed contact 10 and comes into contact with the second fixed contact 11.

Since the capacitor 16 and the resistor 17 constitute a differential circuit, the movable contact 9 is connected to the second fixed contact 1 as described above.
1, the base voltage of the transistor 15 rises momentarily, and then the capacitance of the capacitor 16 and the resistor 1
The voltage decreases with a waveform determined by a time constant determined by the resistance value of 7. Then, when the base voltage of the transistor 15 drops to a certain value, the transistor 15,
Consequently, the transistor 18 is turned on, and current flows from the battery 14 to the shape memory alloy 8. Further, when the base voltage of transistor 15 further decreases and reaches a certain value, transistors 15 and 18 are turned off, and the current supply to shape memory alloy 8 is stopped.

Therefore, the shape memory alloy 8 is energized after a predetermined period of time has elapsed since the movable contact 9 contacts the second fixed contact 11, and the energization to the shape memory alloy 8 is stopped after a further predetermined period of time has elapsed.

Further, when the shape memory alloy 8 is energized as described above, the shape memory alloy 8 is heated to a predetermined temperature range by Joule heat, and the shape memory alloy 8 returns to the memorized length due to the shape memory effect. As a result, the locking member 6 is rotated clockwise against the locking spring 7, and the hook portion 6a of the locking member 6 is disengaged from the locking pawl 3a of the locking member 3. Then, the locked member 3 is rotated counterclockwise together with the rotating shaft 1 by the force of the drive spring 4, returning to the state shown in FIGS. 1 and 2, but in the process, the shutter of the camera is activated.

As a result of the above, the button part 12 of the self-timer operating member 12
The shutter will be released after a predetermined period of time has elapsed since b was pressed.

Further, when the locked member 3 returns to the release position shown in FIGS. 1 and 2 as described above, the movable contact pressing claw 12 of the locked member 3
b no longer presses the movable contact 9, the movable contact 9 separates from the second fixed contact 11 and comes into contact with the first fixed contact 10. Therefore, capacitor 16 is discharged. Then, the push button portion 12b also returns to its initial position due to the elasticity of the spring portion 12a, since the engagement between the locking pawl 12c and the movable contact 9 is released.

Next, the film is wound again from the state shown in FIGS. 1 and 2 to the state shown in FIGS. 3 and 4, and then the button part 12
If b is pressed, the above operation is repeated and the shutter is released after a predetermined period of time has elapsed.

Note that in this embodiment, in the state where the film is not wound, that is, in the state shown in FIGS. Since it is not pressed by the claw 3b, it does not come into contact with the second fixed contact 11. Therefore, no current is passed through the shape memory alloy 8, and the shutter is not released. In this case, button part 1
If the finger is released from 2b, the locking pawl 12c will not engage with the movable contact 9, so the button portion 12b will be held in place by the spring portion 12.
It returns to its initial position due to the elasticity of a.

Furthermore, when the shutter button (not shown) is manually pressed in the state shown in FIGS. 3 and 4 when the film is wound up, the locking member 6 is immediately rotated clockwise and the shutter is immediately released. It will be done.

This timer device has a simple structure and does not require expensive parts, so manufacturing costs can be reduced. Moreover, since the shape memory alloy 8 can be operated at a very low voltage of, for example, 1.5 V or less, it can be operated with one battery. Furthermore, this timer device
Since it does not use an actuator or spring mechanism that uses electromagnetic force, it can occupy a very small space.

Although the above embodiment is an example in which the timer device of the present invention is applied to a self-timer device of a disposable camera, the timer device of the present invention can of course be applied to a normal camera that is not disposable. It is also applicable to timer devices other than self-timers.

〔Effect of the invention〕

As described above, the timer device according to the present invention (a) has a simple structure and does not require expensive parts, so manufacturing costs can be reduced.

(b) Since a shape memory alloy is used as an actuator, it can be operated with a very low voltage.

(c) Since no actuator or spring mechanism that utilizes electromagnetic force is used, the space occupied can be made extremely small.

This provides an excellent effect.

[Brief explanation of drawings]

Fig. 1 is a plan view showing an embodiment of the timer device according to the present invention in a state where the film is not wound;
This figure is a front view showing a part of the embodiment in the same state as in FIG. 1, and FIG. 3 shows the embodiment in a state where the film is wound up but the button part of the self-timer operating member is not pressed down. FIG. 4 is a front view showing a part of the embodiment in the same state as FIG. 3, and FIG. 5 is a state where the film is wound up and the button part of the self-timer operating member is pressed down. 6 is a front view showing a part of the embodiment in the same state as FIG. 5, and FIG. 7 is a circuit configuration diagram showing the delay circuit and drive circuit in the embodiment. be. 2... Body, 3... Locked member, 4... Drive spring, 6... Locking member, 7... Locking spring, 8... Shape memory alloy, 9... Movable contact, 11... second fixed contact, 12... self-timer operating member.

Claims (1)

[Scope of Claims] 1. A locked member movable between a predetermined standby position and a predetermined release position, and a drive spring that biases the locked member from the standby position toward the release position. means, a locking member movable between a locking position where the locked member is locked in the standby position and a locking release position where the locking is released, and a shape recovery force applied to the locking member. a shape memory alloy that acts in a direction to move the locking member toward the unlocked position; a drive circuit that energizes the shape memory alloy; and a drive circuit that turns on the drive circuit after a predetermined time has elapsed after receiving a predetermined input. and a delay circuit that causes the drive circuit to energize the shape memory alloy. 2. The timer device according to claim 1, wherein when the locked member is moved from the standby position to the release position, a shutter of the camera is actuated; It has a self-timer operating member that is movable relative to the body, and two contacts that come into contact with each other when the self-timer operating member is moved to a predetermined self-timer operating position in a state where the film is wound up. A self-timer device for a camera, wherein the delay circuit receives the predetermined input when the two contacts are brought into contact.