JP2552429Y2 - Shutter device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a shutter device used for a camera or the like.

[Conventional technology]

2. Description of the Related Art Conventionally, as a driving source for a camera or the like, a stepping motor having excellent controllability for a small rotation of one rotation or less has been known. Recently, an ultrasonic motor that can obtain a high torque even at a low speed rotation has been provided. As one form of such an ultrasonic motor, a motor using a sound piece is known. The sound piece is a piece in which a piezoelectric element, for example, a piezoelectric ceramic is attached to two adjacent surfaces of an elastic body having a rectangular cross section, and a high frequency voltage is applied by giving a phase difference to these piezoelectric ceramics. A traveling wave is generated on the surface of the elastic body. By bringing a predetermined member into contact with the sound piece, the member can be moved (for example, JP-A-62-277079).

On the other hand, in a compact camera or the like, a behind-type shutter using two blades that are also used as aperture blades is often used. The two shutter blades are rotatable about their respective axes, and one pin is commonly engaged with a long hole formed in both shutter blades. By moving this pin, the shutter blades are opened and closed.

[Problems to be solved by the invention]

It is conceivable to drive the shutter as described above using the above-described sound piece, but it has been difficult to perform accurate exposure amount control with a simple configuration.

[Purpose of the invention]

The present invention has been made to solve the above-described problems, and has as its object to provide a shutter device having a simple structure capable of performing exposure control with high accuracy.

[Means for solving the problem]

In order to achieve the above object, a shutter device according to claim 1 of the present invention has two piezoelectric ceramics fixed to an elastic body so that their vibration directions are different from each other, and the phase of the piezoelectric ceramics is fixed to these piezoelectric ceramics. A vibrator for generating a mechanical vibration accompanied by turning on the elastic body by applying different vibration voltages, and controlling the phase to selectively select a direction of the turning; A displacement member that is displaced by mechanical vibration of the elastic body in contact with the elastic body, and pressing means for pressing the displacement member against the sound piece side such that the displacement member contacts the elastic body of the sound piece;
A plurality of shutter blades driven by the displacement of the displacement member to open and close the exposure aperture in conjunction with each other, and a blade displacement disposed on a displacement trajectory of at least one of the shutter blades and detecting a displacement position of the shutter blade. The shutter is opened by displacing the displacing member to one side by mechanical vibration of the elastic body accompanied by turning to one side, and the shutter blade is displaced to a position corresponding to the subject luminance. When the blade is detected by the blade displacement position detecting means, the elastic member generates mechanical vibration accompanied by turning to the other side, and displaces the displacement member to the other side to close the shutter blade.

The shutter device according to claim 2 of the utility model registration is the shutter device according to the utility model registration claim 1, wherein the displacement member is one of the shutter blades, or This is a member integrally provided on one of the shutter blades.

Further, in the shutter device according to the third aspect of the present invention, two piezoelectric ceramics are fixed to the elastic body so that the respective vibration directions are different from each other, and vibration voltages having different phases are applied to these piezoelectric ceramics. By causing the elastic body to generate mechanical vibration accompanied by turning,
A sound piece for which the direction of the turning is selected alternatively by controlling the phase, a connecting means for connecting the two sound pieces in opposition to each other, and a part sandwiched between these sound pieces;
A displacement member that is displaced in two directions corresponding to a turning direction of mechanical vibration generated in each elastic body, and a plurality of shutter blades that are driven by the displacement of the displacement member and that open and close the exposure opening in conjunction with each other, A blade displacement position detecting means arranged on at least one displacement trajectory of the shutter blades for detecting a displacement position of the shutter blade; And the displacement member is displaced to one side to open the shutter blade, and when it is detected by the blade displacement position detecting means that the shutter blade has been displaced to a position corresponding to the luminance of the subject, the elastic member is moved to the other. Mechanical vibration accompanying the turning of the shutter blade is generated, and the combined vibration causes the displacement member to be displaced to the other side to close the shutter blade.

Further, in the shutter device according to the fourth aspect of the present invention, in the shutter device according to the third aspect, the displacement member is one of the shutter blades, or This is a member integrally provided on one of the shutter blades.

[Action]

According to the above configuration, in the shutter device of the present invention, when the piezoelectric ceramic is driven, the sound piece vibrates, the shutter blade is displaced by the vibration, and the displaced position is detected. Is changed and the exposure opening is opened and closed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

〔Example〕

In FIGS. 1 and 2 showing a shutter device 1 according to a first embodiment of the present invention, an inner wall surface 6 of a camera (not shown) is shown.
The shutter blades 2 and 3 are respectively mounted rotatably around shafts 4 and 5 fixed to the shutter blades. The shutter blade 2 is provided with a long hole 2a, and a projection 3a engaged with the long hole 2a is provided on the shutter blade 3. Accordingly, when one of the shutter blades 2 is rotated, the shutter blade 3 is rotated in the opposite direction to the shutter blade 2 in conjunction therewith. Shutter blade 2,3
Cover the exposure opening 7 formed in the wall surface 6 when they overlap with each other, and open the exposure opening 7 when they are turned away from each other. A small hole 9 for detecting the rotation position of the shutter blade 2 is provided in a peripheral portion 2b of the shutter blade 2 by a photo sensor 8 as a blade displacement position detecting means.
Are provided along the rotation trajectory of the shutter blade 2.

Behind the shutter blade 2, this shutter blade 2
A sound piece 10 is provided in contact with. The resonating piece 10 includes an elastic body 11 made of a regular quadrangular prism soft rope, and a well-known piezoelectric ceramic (for example, PZT or the like) 14, When a voltage is applied to these piezoelectric ceramics 14 and 15 to cause electrical excitation having a phase difference of 90 ° to occur, the displacement of the central portion of the elastic body 11 makes a turning motion. .

The sound piece 10 is provided with screws 18 and 19 in grooves 17 provided in the wall surface 6.
Installed by. A cushioning material 20 is provided between the heads of the screws 18 and 19 and the sound piece 10, and a cushioning material 21 is provided between the sound piece 10 and the bottom of the groove 17, respectively. It is absorbed so as not to be transmitted directly to the wall surface 6. Further, the shutter blade 2 is located between the sound piece 10 and the position opposite to the sound piece 10.
A pressing roller 25 is provided so as to sandwich the pressing roller 25, and the pressing roller 25 is attached to the wall 26 via a metal fitting 26 and an arm 27 rotatably attached thereto.
Although not shown, the arm 27 is a sound piece above the arm 27.
A spring biasing in the direction of 10 is provided.

The operation of the shutter device 1 configured as described above will be described. When a shutter button (not shown) is pressed, an oscillating voltage having a phase shifted by 90 ° is applied to the piezoelectric ceramic disks 14 and 15, thereby causing the elastic member 11 to mechanically rotate the shutter blade 2 in a counterclockwise direction. Vibration occurs. Thus, when the shutter blade 2 rotates about the shaft 4, the projection 3a
The shutter blade 3 is also rotated by being pressed at the end portion 2a, and the exposure opening 7 is opened. At this time, since the amount of rotation of the shutter blades 2 and 3 is determined according to the brightness of the subject, the moment the shutter blade 2 is rotated up to this amount of rotation, the photo sensor 8 detects the small hole 9 corresponding to the position. In accordance with a command signal from the photo sensor 8, an oscillating voltage having an opposite phase difference is applied to the piezoelectric ceramics 14,15. As a result, the vibration direction of the sound piece 10 is reversed, the shutter blades 2 and 3 are rotated in the reverse direction, the exposure opening 7 is closed, and the exposure is completed.

Next, the shutter device 30 according to the second embodiment of the present invention is
This will be described with reference to FIGS. In the state where the sound pieces 31 and 32 similar to the sound piece shown in the first embodiment sandwich the rod-shaped member 33,
As shown in FIG. 4, it is attached to the frame 36 by screws 34, 35. These screws 34 and 35 have cushioning materials 37 and 38 and springs.
39 and 40 are passed therethrough, whereby the bar-shaped member 33 is brought into close contact with the sound pieces 31 and 32 with an appropriate tightening force. In addition,
Grooves 41a are formed on the lower surface of the elastic body 41 of the sound piece 31 and grooves 42a are formed on the upper surface of the elastic body 42 of the sound piece 32 so that the rod-shaped member 33 does not move in a direction other than at right angles to the sound pieces 31 and 32. ing. Note that a protrusion 33a is provided at an end of the rod-shaped member 33.

The sound pieces 31 and 32 have piezoelectric ceramics 45 and 4 respectively.
6, 47 and 48 are provided, and are arranged so as to be symmetrical as shown in the figure. Piezoelectric ceramics 45 and 46 and
Apply oscillating voltages with 90 ° phase difference to 47 and 48 respectively.
Revolving motions in opposite directions are generated at the lower surface center portion of the elastic body 41 and the upper surface center portion of the elastic body 42, respectively. As a result, the rod-shaped member 33 sandwiched between the groove 41a and the groove 42a is moved by the mechanical combined vibration of the sound pieces 31 and 32.

On the other hand, as shown in FIG. 3, shutter blades 51 and 52 are rotatably attached to the wall surface provided with the exposure opening 50 via shafts 53 and 54, respectively. Shutter blade 51,5
2 are provided with slots 51a and 52a, respectively.
The projections 33a of the rod-shaped member 33 are engaged with 51a and 52a.
When the rod 33 is moved back and forth, the shutter blades 51 and 52 are simultaneously rotated in opposite directions, and the
Is opened and closed. The end of the shutter blade 51 has a number of small holes to be detected by the photo sensor 8.
51b is provided.

The operation of the shutter device 30 configured as described above will be described. When you press the shutter button, each piezoelectric ceramic
45, 46, 47, 48 are driven, and mechanical vibrations are generated in the sound pieces 31, 32 due to the turning motions in opposite directions. Thereby, the rod-shaped member 33 is moved in the direction of the arrow in FIG. 3, and the projection 33a simultaneously presses the ends of the long holes 51a and 52a. Shutter blades 51, 52
Are rotated in opposite directions to open the exposure opening 50. At this time, the shutter blades 51 and 52 are
Of the shutter blade 51 up to this amount of rotation.
At the moment when is rotated, the photo sensor 8 detects the small hole 51b corresponding to the position, and the piezoelectric ceramics 45, 46 and 47 and
The phase of the voltage applied to 48 is reversed. As a result, the directions of the turning movements of the sound pieces 31 and 32 are reversed, and the rod-shaped members 3
3 is moved in the opposite direction, the shutter blades 51 and 52 are rotated in the opposite direction, and the exposure opening 50 is closed.

Note that one of the shutter blades 51 and 52 can be inserted between the two sound pieces 31 and 32 without using the rod-shaped member 33, and the shutter blades can be directly driven by the two sound pieces. . In this case, an elongated projection is formed at the lower end of one of the shutter blades 51, 52 shown in FIG. 3, or a separate rod member is fixed to one end of the shutter blades 51, 52. Then, the protrusion or the rod-shaped member may be inserted between the two sound pieces.

Next, a motor 60, which is a main part of the shutter device according to the third embodiment of the present invention, will be described with reference to FIGS. Gold frame
Two sound pieces 64, 65 are arranged on 61 via screws 62, 63, and a disk 66 having an end sandwiched between the sound pieces 64, 65 is turned around the screw 62. It is movably mounted. Above and below the sound pieces 64 and 65, cushioning materials 67 and 68 and springs 69 and 70 passed through the screws 62 and 63 are provided.
Are appropriately tightened from above and below by the sound pieces 64 and 65.

Piezoelectric ceramics 45, 46, 47, 48 are arranged on the sound pieces 64, 65 so as to be vertically symmetric as in the second embodiment, and these piezoelectric ceramics 45, 46, 47, 48 are driven. As a result, mechanical vibrations are generated in the sound pieces 64 and 65 due to turning motions in opposite directions. When the sound pieces 64 and 65 are driven, the end of the disk 66 is given a tangential thrust,
The disk 66 is rotated around the screw 62. This rotation direction can be easily changed by reversing the phase direction of the vibration voltage applied to the piezoelectric ceramic.

The disk 66 is integrally provided with a projection 72 having a projection 71. For example, if the projection 71 is connected to a shutter blade as shown in the second embodiment, the motor 60 opens and closes the shutter blade. be able to. In addition, without using disk 66,
One of the shutter blades as shown in the second embodiment may be rotatably mounted around a screw 63, and this shutter blade may be directly driven to rotate by two sound pieces 64 and 65. In addition, it goes without saying that the motor 60 can be used as a drive source for an electronic still camera or the like.

[Effect of the invention]

As described above, according to the shutter device of the present invention, the shutter blade is driven by the sound piece, and the displacement position of the shutter blade is detected and controlled in accordance with the luminance of the subject. Although the shutter device has a simple structure, it is possible to provide a shutter device having extremely high exposure accuracy, which can contribute to downsizing of the camera, cost reduction, and improvement in exposure accuracy.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of a first embodiment of the present invention. FIG. 2 is an end view of an essential part of the first embodiment of the present invention, in which a part is cut away. FIG. 3 is a plan view of a main part of a second embodiment of the present invention. FIG. 4 is an end view of a main part of a second embodiment of the present invention. FIG. 5 is a plan view of a main part of a third embodiment of the present invention. FIG. 6 is an end view of a main part of a third embodiment of the present invention. 1,30 shutter device 2,3,51,54 shutter blade 10,31,32,64,65 sound piece 11,41,42 elastic body 14,15,45,46,47,48 piezoelectric ceramic 25 ... Pressing roller 33 ... Bar member 60 ... Motor 66 ... Disc.

Claims (4)

(57) [Scope of request for utility model registration] 1. An elastic body having two vibration directions different from each other.
A sheet of piezoelectric ceramics is fixed, and a vibrating voltage having a different phase is applied to these piezoelectric ceramics to generate mechanical vibration with a rotation in the elastic body, and the direction of the rotation is controlled by controlling the phase. Is selected as an alternative, a displacement member that comes into contact with the elastic body of the sound piece and is displaced by mechanical vibration of the elastic body, and the displacement member contacts the elastic body of the sound piece. Pressing means for pressing the displacement member toward the sound piece side; a plurality of shutter blades driven by the displacement of the displacement member to open and close the exposure aperture in conjunction with each other; and arranged on a displacement trajectory of at least one of the shutter blades. And a blade displacement position detecting means for detecting a displacement position of the shutter blade,
The displacement member is displaced to one side by mechanical vibration of the elastic body accompanied by one turn to open the shutter blade, and the displacement of the shutter blade to a position corresponding to the subject brightness is detected by the blade displacement position detecting means. A shutter device wherein a mechanical vibration accompanied by turning to the other side is generated in the elastic body when detected, and the displacement member is displaced to the other side to close the shutter blade. 2. The utility model registration according to claim 1, wherein said displacement member is one of said shutter blades or a member integrally provided on one of said shutter blades. 2. The shutter device according to claim 1. 3. An elastic body having two vibration directions different from each other.
A sheet of piezoelectric ceramics is fixed, and a vibrating voltage having a different phase is applied to these piezoelectric ceramics to generate mechanical vibration with a rotation in the elastic body, and the direction of the rotation is controlled by controlling the phase. Is selected as an alternative, a connecting means for connecting two of the sound pieces in opposition to each other, and a mechanical vibration generated in each elastic body, with a part being sandwiched between these sound pieces. A displacement member that is displaced in two directions in accordance with the turning direction of the shutter, a plurality of shutter blades that are driven by the displacement of the displacement member and that open and close the exposure opening in conjunction with each other, and at least one of the shutter blades A blade displacement position detecting means arranged on the displacement trajectory and detecting a displacement position of the shutter blade,
Synthesizing mechanical vibration with one turn generated in each elastic body, displaces the displacement member to one side, opens the shutter blade, and displaces the shutter blade to a position corresponding to the subject luminance. Each of the elastic members generates mechanical vibration accompanied by turning to the other when detected by the blade displacement position detecting means, and the combined member causes the displacement member to be displaced to the other to close the shutter blade. Characteristic shutter device. 4. The utility model registration according to claim 1, wherein said displacement member is one of said shutter blades or a member integrally provided on one of said shutter blades. 4. The shutter device according to claim 3.