JP2001358481A - Heat radiative mechanism of shutter for electromotive camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the heat radiative mechanism of a shutter for an electromotive camera, which is so arranged as to ideally radiate the heat generated by a motor for driving the vane of a shutter. SOLUTION: A motor for driving the vane of a shutter and a flexible printed wiring board 13 are attached to a shutter's base plate 7a made of synthetic resin. Moreover, the motor has a stator frame 10 made of synthetic resin bearing a rotor, a coil 11 wound thereon, and a cylindrical yoke 12 surrounding them. On the other hand, for the flexible printed wiring board 13, a copper foil pattern for power supply to the coil 11 is made between band parts 13a and 13c, and a copper foil pattern for heat conductivity is made between the band parts 13a and 13c. Then, for the copper foil pattern for heat conductivity, its one end is in contact with the yoke 12, and its other end is in contact with a metallic member on the side of the camera main body. Accordingly, the heat generated in the coil 11 is radiated ideally.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat radiating mechanism effective for use in an electric camera shutter in which a motor operates shutter blades.

[0002]

2. Description of the Related Art Recently, even in digital cameras,
Electrification of cameras using film is also rapidly progressing. Therefore, in the case of a lens shutter, a considerable number of shutter blades are operated by a motor. Also, in the case of a focal plane shutter,
The demand for doing so is growing. In most cases, the motor used so far is a stepping motor or a current control type motor called a moving magnet type motor. Also,
In the case of the latter motor, a spring force may be applied to the opening operation of the shutter blades depending on the specification.

[0003] Several types of configurations are known as such a moving magnet type motor.
A typical configuration example among them is disclosed in JP-A-2000-66.
267 and JP-A-2000-78808. In this type of motor, a rotor made of a permanent magnet magnetized to two poles usually has an output pin (drive pin) extending in parallel with a rotation axis at a radial position of the rotor. Is configured to be rotatable in a predetermined angle range in a direction corresponding to a direction of energization to the stator coil, and is characterized by being low-cost and easy to be miniaturized. When,
There is a problem that the stop position of the rotor becomes unstable. Therefore, in order to reliably maintain the stopped state of the shutter blades in the fully open position and the closed position, if the energized state to the stator coil is continued or the energized state is cut off, it is described in the above publication. Is necessary.

On the other hand, since there is also an advantage in terms of weight reduction, recently, considerable parts have been made of synthetic resin, and almost all camera housings and lens barrels are made of synthetic resin. It is becoming. So, of course,
Even in the case of a shutter as a camera part, most parts are made of synthetic resin as long as the performance can be maintained, and many of the above-mentioned motors are made of synthetic resin. The shutter base plate to which the lens shutter is attached is almost always made of synthetic resin in the lens shutter.

[0005]

It is known that when electricity is supplied to a motor, heat is generated from a coil. However, as in the past, if the motor parts are mostly made of metal, the influence is not affected. Even if many synthetic resin parts are used for the motor, if the shutter base plate is made of metal, heat is radiated and the motor is not affected. The temperature of the synthetic resin parts does not become high. However, as described above, when a synthetic resin part is used for the motor and the shutter base plate is also made of synthetic resin, even if there is no particular problem in shooting in daylight, in which the power is supplied only for a short time, the power is not supplied. This can be problematic depending on the method.

That is, in this type of shutter, when the subject is dark or when bulb photography is selected from the beginning, the shutter blades must be kept fully open for a long time. In these cases, even if the energization of the coil is cut off in the fully opened state, there is no way to keep the shutter blade in the fully opened state as described above. However, there is a case where it is not desired to cut off the power supply in the fully open state for the convenience of circuit design. Further, in a camera using a film, since it is rather desired to give priority to the holding force in the closed state, there may be a configuration in which the holding force in the fully opened state cannot be sufficiently obtained. Therefore, in such cases,
In the fully opened state, the power supply to the coil is continued. In addition, when manufacturing a camera, for example, when focusing a lens, the shutter blades must be fully opened, but at that time, a considerable amount of time is required.
In some cases, the power must be kept on.

As described above, the longer the current supply time to the coil, the larger the amount of heat stored in the synthetic resin part of the motor. It is known that when the surface of the coil is measured, the part is deformed. In particular, when the bearing member of the rotor is made of a synthetic resin and the coil is wound around the bearing member, in extreme cases, the effect on the operating characteristics of the shutter blades may be increased. Can be

For this reason, when the subject is dark and the exposure is performed for a long time, or when the bulb photography is selected from the beginning, the synthetic resin part of the motor is deformed, and the shutter blade is properly closed. Operation may not be possible. However, in the case of long-time photographing, such an event has almost no effect on the overall exposure time. However, if the next shooting is performed at high speed immediately after the long-time shooting and at the stage where the heat of the synthetic resin parts has not yet sufficiently radiated naturally, shooting with the appropriate exposure time is required. There was a problem that it would not be possible. Also, when making the camera,
In order to focus the lens, it is necessary to finish the operation before the heat is stored and the temperature becomes high (for example, within one minute) or to wait until the temperature is sufficiently lowered. There was a problem that the next inspection such as speed could not be performed.

The present invention has been made in order to solve such a problem, and an object of the present invention is to appropriately dissipate heat without accumulating heat generated by a motor for driving shutter blades. An object of the present invention is to provide a low-cost heat radiating mechanism in an electric camera shutter that can prevent deformation of a synthetic resin part.

[0010]

In order to achieve the above object, a heat radiating mechanism for a camera shutter according to the present invention comprises:
A flexible printed wiring board mounted on a shutter of a type in which a shutter blade is driven by a motor and formed with a copper foil pattern for connecting to one or more electronic components mounted on the shutter; Separately, a copper foil pattern dedicated to heat conduction is formed, and one end of the copper foil pattern dedicated to heat conduction is brought into contact with the motor, and the other end is brought into contact with a metal member on the camera body side. To

Further, in the heat radiation mechanism for a camera shutter according to the present invention, when one of the electronic components is the motor, the work of attaching the shutter to the camera body becomes easy.

Further, the copper foil pattern dedicated to heat conduction is
When the one end is brought into contact with the outer peripheral surface of the metal outer cylinder of the motor, the contact area can be increased, and the heat radiation effect is increased.

Further, when the flexible printed wiring board is attached with a slack between the shutter and a member on the camera body side, and the shutter is movable in the optical axis direction, a so-called collapsible lens is provided. It is effective when applied to an expression camera.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to FIGS.
This will be described with reference to the embodiment shown in FIG. FIG. 1 is a sectional view schematically showing a mounting structure of the present embodiment in a camera, FIG. 2 is an explanatory view showing a mounting structure of a flexible printed wiring board to a shutter, and FIG. FIG. 3 is a development view of a part of the flexible printed wiring board shown in FIG.

The outer case 1 of the camera shown in FIG. 1 is made of metal. As is well known, such an outer casing 1 is hardly composed of a single component, and has a complicated configuration such that a film loading lid is provided on the back and bottom of the camera. However, such a specific configuration is conceptually shown in FIG. 1 because it is not particularly necessary for the description of the present invention. A hard printed wiring board 2 is attached to a member (not shown) of the camera body integrated with the outer casing 1. Various semiconductor components necessary for controlling the camera are mounted on the hard printed wiring board 2, and an LCD display device and the like can be mounted so as to enable observation from above the camera. I have.

A fixed cylinder 3 is attached to the outer casing 1. In the fixed cylinder 3, three linear guide grooves 3a parallel to the optical axis are actually formed at equal angular positions around the optical axis. Two of them are visible and shown. The fixed cylinder 3 has a notch 3b, which is open on the film side, formed in a straight line parallel to the optical axis. A distance ring 4 that is rotated by a distance adjusting device (not shown) is fitted on the outer peripheral surface of the fixed cylinder 3, and includes a linear portion parallel to the optical axis and an end on the subject side. Cam groove 4 having a substantially spirally formed cam portion from the portion
a is formed. When the camera shown in FIG. 1 is not used, the straight portions of the three cam grooves 4 a are arranged so as to overlap with the guide grooves 3 a of the fixed cylinder 3.

A lens barrel 5 made of synthetic resin is fitted on the inner peripheral surface of the fixed barrel 3, and is linearly moved along the optical axis by a feeding device (not shown). I have. A lens 6 is provided on the object side of the lens barrel 5.
A shutter 7 is mounted on the film side by a well-known method (not shown). Also, between them, in the state of FIG.
Three linear guide grooves 5a having a short length are formed parallel to the optical axis at positions overlapping with a. An annular synthetic resin lens frame 8 is provided inside such a lens barrel 5.
Is disposed, and a lens 9 is attached inside.
On the outer peripheral surface of the lens frame 8, there are provided three pins 8a protruding in the radial direction. In the state of FIG. 1, the pins 8a are formed on the straight portions of the guide grooves 3a and 5a and the cam groove 4a. Mated.

Although not shown in detail in the drawings, the shutter 7 of this embodiment has a well-known configuration. That is, a synthetic resin shutter base plate 7a disposed on the subject side and a synthetic resin auxiliary base plate 7b disposed on the film side are separated from each other.
They are attached to each other by a method not shown, and a blade chamber of a shutter blade is formed therebetween. The moving magnet type motor is mounted on the subject side surface of the shutter base plate 7a, and the output pin (drive pin) of the rotor is inserted into the blade chamber to open and close the shutter blade. . In FIG. 2, a portion of the stator frame 10 made of synthetic resin that supports the rotor, a coil 11 wound around the portion, and a cylinder attached so as to surround them. Only the yoke 12 is shown.

A flexible printed wiring board 13 is attached to the shutter 7 having such a known configuration. The flexible printed wiring board 13 of the present embodiment
It has an elongated strip shape, with both ends divided into two strips. And the flexible printed wiring board 13
As shown in FIG. 2, two band portions 13a,
13b is attached to the shutter base plate 7a with five screws 14, and the tip of one of the two band portions 13c and 13d at the other end is soldered to the printed wiring board 2 as shown in FIG. The other end of the band 13 d is attached to the outer casing 1 by two screws 15.

Such a flexible printed wiring board 1
In the present embodiment, a copper foil pattern for supplying power to the coil 11 is formed between the third band portion 13a and the third band portion 13c. Further, independently of such a copper foil pattern, a copper foil pattern exclusively for heat conduction is formed between the band portions 13b and 13d. Then, as shown in FIG. 3, the tip of the band portion 13 b is approximately 90
After the mountain fold, the valley fold is made approximately 180 ° along the dashed line B, and the exposed portion L1 of the copper foil pattern is brought into contact with the peripheral surface of the yoke 12 as shown in FIG. Also, at the tip of the band 13d, the exposed portion L is formed on the copper foil pattern.
2 is provided, which is in contact with the outer casing 1.

The camera shown in FIG. 1 is generally called a collapsible camera, and the lens barrel 5 is housed in the outer casing 1 when not in use. Then, when the power is turned on prior to photographing, the lens barrel 5 is extended toward the subject by driving means (not shown), but the pins 8a of the lens frame 8 are fitted into the guide grooves 3a, 5a. , The movement is linear. For this reason, the shutter 7 also moves to the subject side. However, since the flexible printed wiring board 13 has a slack and the fixed cylinder 3 has the notch 3b, the flexible printed wiring board 13 is not provided. 13 does not hinder the movement of the shutter 7. When the lens barrel 5 is stopped at the extended position, the pin 8a of the lens frame 8 is stopped.
Has reached the left end position of the linear portion in the cam groove 4a of the distance ring 4, and is in a state where it can enter the spiral cam portion when the distance ring 4 is rotated.

Next, when the release button is pressed during photographing, first, the distance measuring device operates to rotate the distance ring 4 by a predetermined angle. Therefore, the lens frame 8 is
Is pushed by the cam portion of the cam groove 4a and is moved within the length range of the guide groove 5a, and focusing is performed. When focusing is completed in this way, a forward current is supplied to the coil 11 via the flexible printed wiring board 13. Therefore, the rotor rotates in a predetermined direction, and the shutter blade is fully opened. Then, in the case of the present embodiment, in the fully opened state, the current is continuously supplied to the coil 11. Therefore, when photographing is performed for a long time, the amount of heat generated by the coil 11 increases, but the exposed portion L1 of the body foil pattern dedicated to heat conduction is
Most of the heat is dissipated to the outer casing 1 via the flexible printed wiring board 13 because of the contact with the outer peripheral surface of the outer casing 1. Therefore, there is no possibility that the stator frame 10 made of synthetic resin is deformed.

Thereafter, when a close signal is issued from the exposure time control circuit, a current in the opposite direction is supplied to the coil 11, so that the rotor is rotated in the opposite direction to the previous one.
Close the shutter blade. Thereby, the distance ring 4
Is returned to the position before photographing, so that the pin 8a of the lens frame 8 is guided to the cam portion of the cam groove 4a, and returns to the boundary position with the linear portion. Therefore, if the next photographing is immediately performed in this state, the shutter blades perform a stable opening and closing operation without being affected by the above-mentioned heat generation at all. If the power is turned off without first turning on the power, the driving means (not shown) moves the lens barrel 5 to the film side and returns to the state shown in FIG.

In the above embodiment, one end of the copper foil pattern for heat conduction formed on the flexible printed wiring board 13 is in contact with the outer casing 1 of the camera.
The metal member provided on the camera body side is not limited to the outer casing 1. Further, in the above-described embodiment, the case where the moving magnet type motor in which the rotor can rotate only within a predetermined angle range is used as the motor for driving the shutter blades is described. The present invention is also applied to a case where a normal DC motor capable of rotating more than the rotation is used. Furthermore, even when a moving magnet type motor is used, a method of intermittently supplying current to the coil 11 instead of continuously supplying the current to the coil 11 as in the above-described embodiment is known. However, the invention also applies to such a case.

In the above embodiment, two strips 13a and 13b are formed to attach the flexible printed wiring board 13 to the shutter base plate 7a. However, the present invention is limited to such a configuration. Not done. That is,
The copper foil pattern for power supply to the coil 11 shown in FIG. 2 may be formed on the band 13b together with the copper foil pattern for heat conduction. Further, as is well known, in the case of this type of shutter, a photo sensor is often attached to detect the position of the shutter blade, but the flexible printed wiring board 13 has a photo sensor in addition to the motor. It is permissible to form a copper foil pattern to be connected to other electronic components, such as, the power supply to the motor is performed via its own lead wire, and the flexible printed wiring board has a copper foil pattern for other electronic components. A pattern may be formed.

[0026]

As described above, according to the present invention, in a camera shutter to which a motor for driving shutter blades is attached, a flexible printed wiring board is connected to an electronic component attached to the shutter. In addition to the foil pattern, it has a copper foil pattern for heat conduction, one end of the copper foil pattern for heat conduction is brought into contact with the motor, and the other end is brought into contact with a metal member on the camera body side As a result, heat radiation of the motor is suitably performed, and even if a part of the motor, a shutter base plate to which the motor is attached, and the like are made of synthetic resin, no trouble occurs. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a mounting configuration of an embodiment in a camera.

FIG. 2 is an explanatory diagram showing a mounting configuration of a flexible printed wiring board to a shutter in FIG. 1;

FIG. 3 is an expanded view of a part of the flexible printed wiring board in FIGS. 1 and 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer housing 2 Hard printed wiring board 3 Fixed cylinder 3a, 5a Guide groove 3b Notch part 4 Distance ring 4a Cam groove 5 Lens cylinder 6, 9 Lens 7 Shutter 8 Lens frame 8a Pin 10 Stator frame 10 11 Coil 12 Yoke 13 Flexible Printed Wiring Board 13a, 13b, 13c, 13d Strip 14, 15 Screw L1, L2 Exposed Portion of Copper Foil Pattern

Claims (4)

[Claims] 1. A flexible printed wiring board attached to a shutter of a type in which shutter blades are driven by a motor and having a copper foil pattern formed thereon for connection to one or more electronic components attached to the shutter.
A copper foil pattern dedicated to heat conduction is formed separately from the copper foil pattern, and one end of the copper foil pattern dedicated to heat conduction is brought into contact with the motor, and the other end is brought into contact with a metal member on the camera body side. A heat radiating mechanism for a camera shutter, wherein the heat radiating mechanism is provided. 2. The heat radiating mechanism for a camera shutter according to claim 1, wherein one of the electronic components is the motor. 3. The camera shutter according to claim 1, wherein the copper foil pattern dedicated to heat conduction has one end thereof in contact with an outer peripheral surface of a metal outer cylinder of the motor. Heat dissipation mechanism. 4. The flexible printed wiring board is mounted with a slack between the shutter and a member on a camera body side, and the shutter is movable in an optical axis direction. The heat radiating mechanism for a camera shutter according to claim 1.