JP2002031828A - Shutter device also used as diaphragm - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform delicate converging operation and to fulfill requirements such as miniaturization and speeding-up even at the time of photographing an animation or the like by a digital camera or the like. SOLUTION: This shutter device is provided with a shutter blade also used as a diaphragm 30 which is provided so as to be freely movable between an opening position at which an aperture part 10a is opened and a closing position at which is closed and also performs converging operation to set the aperture part 10a to a desired diameter, an electromagnetic actuator 40 to drive the shutter blade, detecting means 56 and 57 to detect the luminance of object light and a controlling part 51 to control the electromagnetic actuator 40, and the controlling part 51 controls the electromagnetic actuator 40 so that the shutter blade 30 performs the converging operation so as to automatically attain an optimum diameter in accordance with the output signals of the detecting means 56 and 57.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aperture / shutter device for a camera which opens and closes an opening for exposure and narrows the aperture to a desired aperture, and more particularly to a camera which is suitable for photographing moving images and the like. The present invention relates to an aperture / shutter device for use in a camera.

[0002]

2. Description of the Related Art In a conventional digital still camera, an aperture device having aperture blades for narrowing an aperture for exposure to a predetermined aperture is moved between an open position for opening the aperture and a closed position for closing the aperture. And a shutter device having freely provided shutter blades. This diaphragm device has several apertures (for example, 2 apertures each having a different aperture).
Aperture blades having a diameter suitable for the brightness of the subject light are selected in advance, the aperture is narrowed by the selected aperture blades, and then the shutter operation by the shutter blades is performed. It was to be done.

[0003]

The above-mentioned diaphragm device narrows the aperture stepwise, for example, to two or three steps, so that the aperture is adjusted in accordance with the brightness of the light of the subject. Is not squeezed continuously. Therefore, when a moving image is photographed using such an aperture device or the like, it is not possible to correct the aperture so as to have an optimal aperture according to the brightness of the subject, and there is a concern that the image quality of the moving image is reduced. . Further, in the above-described aperture device and shutter device, the sequence is such that a desired aperture operation is performed after the release operation, and then the shutter operation is performed. Therefore, a time lag due to the aperture operation is required between the release operation and the actual shooting. Had occurred. On the other hand, in digital cameras, etc., although there is a demand for further miniaturization and higher speed, etc.,
It has been difficult to achieve these requirements with the above-described conventional aperture device and shutter device.

[0004] The present invention has been made in view of the above points, and an object of the present invention is to enable a fine aperture operation to be performed even when a moving image or the like is taken by a digital camera or the like, and furthermore, a small-sized camera can be used. It is an object of the present invention to provide a diaphragm / shutter device for a camera which can satisfy the demands for higher speed and higher speed.

[0005]

A diaphragm / shutter device according to the present invention is provided so as to be movable between an open position for opening an exposure opening and a closed position for closing the exposure opening, and has a desired opening. An aperture shutter blade that performs an aperture operation with an aperture, a driving unit that drives the shutter blade, a detection unit that detects the brightness of the subject light, and a control unit that controls the driving unit. Controlling the driving means so as to cause the shutter blade to automatically perform an aperture operation for setting an optimum aperture in response to an output signal of the detection means;
It is characterized by: According to this configuration, for example, when the main switch of the camera is turned on and a moving image is photographed, the control unit controls the driving unit in accordance with the output signal related to the brightness of the subject light output from the detecting unit. In this way, the shutter blade that also serves as the aperture always performs the aperture correction so that the opening has the optimum aperture. As a result, the aperture correction according to the luminance for the moving image that changes every moment is automatically and continuously performed without any level difference, so that the moving image or the like is captured with high image quality.

In the above construction, the control means causes the shutter blade to automatically perform an aperture operation for obtaining an optimum aperture in accordance with an output signal of the detection means before the release operation of the camera, and in response to a signal of the release operation. In this case, the driving means is controlled so as to move the shutter blade to the closed position. According to this configuration, before the release operation, the aperture is previously narrowed to the optimum aperture diameter, and the shutter operation is immediately performed by the release operation. Therefore, there is no time lag between the aperture operation and the shutter operation as in the related art, and high-speed shooting of a still image can be performed.

In the above configuration, the shutter blades are provided at least two blades rotatably provided around a predetermined axis so as to approach and separate from each other, or linearly so as to approach and separate from each other. A configuration including two movably provided blades can be employed. According to these configurations, the continuous aperture operation and the shutter operation from the optimal aperture state are performed by the rotation operation of the shutter blade, or the continuous aperture operation and the optimal operation by the linear reciprocating operation of the shutter blade. The shutter operation is performed from the proper aperture state.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 7 show an embodiment of an aperture / shutter device according to the present invention. In the drawings, for convenience of description, parts that should be dotted lines are indicated by solid lines. As shown in FIGS. 1 to 6, the aperture / shutter device includes a base plate 10 and a holding plate 20 having exposure openings 10a and 20a, an aperture for opening and closing the openings 10a and 20a, and reducing the aperture to a desired diameter. A dual-purpose shutter blade 30, an electromagnetic actuator 40 as a driving unit for driving the shutter blade 30, a detecting unit (a photometer 56 and a photometric circuit 57) for detecting the brightness of subject light, and an electromagnetic actuator 4
A control unit (control unit 51) for controlling 0 is provided as a basic configuration.

As shown in FIG. 2, the main plate 10 and the holding plate 20 are connected so as to define a blade chamber W. In the blade chamber W, a shutter blade 30 also serving as a diaphragm is disposed. An electromagnetic actuator 40 as a driving unit is arranged on the upper surface of the main plate 10. As shown in FIGS. 1 and 2, the electromagnetic actuator 40 has a rotor 41 having a protruding drive pin 41a and magnetized by N and S poles and rotating in a predetermined angle range. Coil 42
, A cylindrical yoke 43, a magnetic pin 44, a Hall element 45 for detecting magnetic flux density, and the like, and are fixed to the base plate 10 via a holding member 46 that holds these. When the magnetic pins 44 act and the shutter blades 30 are at the closed position, the shutter blades 30 are magnetically urged to hold the shutter blades 30 at those positions with the coil 42 not energized.

As shown in FIGS. 4 to 6, the shutter blade 30 which is also used as a diaphragm is composed of a first shutter blade 31 and a second shutter blade 32. The first shutter blade 31 is rotatably supported by the support shaft 10b of the base plate 10, and the second shutter blade 32 is rotatably supported by the support shaft 10c of the base plate 10. Also, the first shutter blade 3
A drive pin 41a of the rotor 41 is connected to the long holes 31a, 32a of the first and second shutter blades 32.

[0011] Then, as shown in FIG.
a rotates substantially downward (the rotor 41 rotates counterclockwise), the shutter blades 30 move to the respective aperture edges 31b,
32b reaches an open position where the opening 10a is completely opened, stops by contacting the stoppers 10d and 10e, and is positioned at that position.

On the other hand, as shown in FIG.
Rotates approximately upward (rotor 41 clockwise),
The shutter blades 30 have respective aperture edges 31b, 32
When b reaches the closing position where the opening 10a is completely closed, and contacts the stopper 10f or moves excessively, it stops by contacting the stopper 10g and is positioned at that position.

Further, as shown in FIG. 5, when the drive pin 41a is held at an intermediate position (the rotor 41 is held at an intermediate rotation angle position) by energizing the coil 42, the shutter blades 30 are respectively moved. The aperture edges 31b and 32b are kept in a state of narrowing the opening 10a to a predetermined diameter. That is, the first shutter blade 31 and the second shutter blade 32 move closer to each other (moving in the direction toward the closed position) and separate from each other (moved to the open position) around the support shafts 10b and 10c in conjunction with the movement of the drive pin 41a. Direction movement)
So that it rotates.

A control system for performing various controls of the apparatus is shown in FIG.
As shown in the block diagram of FIG.
1. A motor drive control circuit 52 for controlling the electromagnetic actuator 40 (motor), a CCD control circuit 54 for controlling the accumulation and release of electric charge of a CCD (imaging device) 53, a CCD 5
3, an image signal processing circuit 55 for performing a storage process and the like of the image signal output from the light source 3, a photometer 56 as a detecting means for detecting the brightness of the subject light, and a photometer circuit 57 for processing the signal output from the photometer 56; A distance measuring device 58 for measuring a distance to a subject, a distance measuring circuit 59 for processing a signal output from the distance measuring device 58, and ON / OF of a power supply of a camera body
Main switch 60 that outputs F signal,
Release switch 61 that outputs an ON / OFF signal, movie switch 62 that outputs an ON / OFF signal for video shooting
And the like.

The control section (control means) 51 controls the shutter blade 3 to perform an aperture operation for automatically setting an optimum aperture in accordance with the output signals of the photometer 56 and the photometer circuit 57 (detection means).
The electromagnetic actuator (drive means) 40 is controlled via a motor drive control circuit 52 so as to make the value 0. The automatic control of the aperture diameter (auto iris control) is performed by increasing / decreasing (controlling) the current applied to the coil 42 and changing the rotational force of the electromagnetic actuator 40. That is, based on the output signals of the photometer 56 and the photometry circuit 57, the control unit 51 performs a calculation to calculate an optimal aperture value. Then, the control unit 51 controls the motor drive control circuit 52 to apply a current value to be applied corresponding to the calculated value to the coil 42 by calculating or extracting the current value to be applied from the calculation or the memory (map). Output a signal. When the coil 42 is energized in response to this control signal, the rotor 41 is driven against the attractive force between the magnetic pin 44 and the magnet (the magnetic pole portion of the rotor 41).
Starts to rotate. Then, at a position where the rotational force and the suction force of the rotor 41 are balanced (balanced), the rotor 41
Stops the rotation. As a result, a desired aperture diameter can be obtained. Further, the control unit (control means) 51 is provided before the release operation of the camera (when the release switch 61 is turned off).
F), the shutter blades perform an aperture operation (auto-iris operation described above) for automatically setting an optimal aperture in accordance with the output signals of the photometer 56 and the photometry circuit 57 (detection means), and the signal of the release operation is output. The electromagnetic actuator (drive means) 40 is controlled via the motor drive control circuit 52 so as to move the shutter blade 30 to the closed position in response to (the release switch 61 is ON).

Next, the operation when the aperture / shutter device is mounted on a digital still camera capable of taking not only a still image but also a moving image will be described. First, when the main switch 60 of the camera is turned on to enter a standby state for photographing, the distance to the subject is measured by the distance measuring device 58 and the distance measuring circuit 59, and a control signal is output from the control section 51 to output the lens driving mechanism. (Not shown) is controlled to perform focusing. At the same time, the brightness of the subject light is detected by the photometer 56 and the photometry circuit 57, and a control signal is output from the control unit 51 to the motor drive control circuit 52 based on the detection signal, and the rotation angle of the electromagnetic actuator 40 is appropriately controlled. Then, the shutter blade 30 narrows the opening 10a so as to have an aperture corresponding to the brightness of the subject light.

For example, when the brightness of the subject light is lower than a predetermined level, as shown in FIG. 4, the shutter blade 30 moves to the open position where the opening 10a is completely opened and does not stop the aperture. When the brightness of the subject light is high, FIG.
As shown in FIG. 6, the shutter blade 30 is in a state where the opening 10a is narrowed to a desired diameter. This aperture operation (auto iris operation) is performed automatically and continuously according to the brightness of the subject light that changes every moment, as shown in FIG.

In the auto iris state, when the movie switch 62 is turned on, a control signal is output from the control unit 51 to the CCD control circuit 54 during that time (until it is turned off), and the control operation of the CCD control circuit 54 is performed. Accordingly, the CCD 53 continuously repeats the accumulation and release of electric charges, and repeats continuous imaging at high speed. And the CCD 53
Are output to an image signal processing circuit 55, where various processes such as storage are performed. At the time of shooting a moving image, the shutter blade 30 also serving as an aperture is always driven and controlled, and fine control is performed so as to have an optimal aperture diameter corresponding to the luminance of the subject light. You can shoot.

On the other hand, when the release switch 61 is turned on in the aforementioned auto iris state, the CCD 5
3, the control unit 51 outputs a control signal to the motor drive control circuit 52, and the electromagnetic actuator 40 immediately moves the shutter blade 30 to the closed position to perform a shutter operation. This allows
The shooting of the still image is completed. Then, the image signal output from the CCD 53 is guided to an image signal processing circuit 55, where various processing such as storage is performed.

At the time of photographing the still image, since the optimal aperture operation has already been performed immediately before the release operation, the shutter blade 30 which also serves as the aperture is immediately moved to the closed position to perform the shutter operation. It is possible to prevent a time lag until the photographing is completed, as compared with the case where the aperture operation is performed after the release operation, and it is possible to perform rapid photographing. In addition, even when still images are continuously shot, the speed can be increased.

FIGS. 8 to 10 show another embodiment of the aperture / shutter device according to the present invention, in which the shutter blades and a part of the drive mechanism for the shutter blades are modified from the above-described embodiment. is there. The other configuration is the same as that of the above-described embodiment, and the description thereof will not be repeated. As shown in FIGS. 8 to 10, the aperture / shutter device according to this embodiment includes an opening 10
The shutter blade 300 is also provided with a shutter blade 300 that also serves as an aperture stop for opening / closing a desired aperture and a desired aperture. The shutter blade 300 includes a first shutter blade 310 and a second shutter blade 320.
Consists of single blades. The first shutter blade 310 is
Opening 310a having substantially the same diameter as the opening 100a
(See FIG. 9), guide slots 310b, 310c, 31
0d, a long hole 310f for connecting to the link member, etc., and the second shutter blade 320
Opening 320a having substantially the same diameter as the opening 10a
(Refer to FIG. 9), long holes for guidance 320b, 320d, 32
0e, a long hole 320f and the like for connecting to the link member.

The slots 310b, 310c, 310
d, the guide pins 100b, 100 of the main plate 100
The first shutter blade 310 is freely movable in the extending direction of the long holes 310b, 310c, 310d, respectively. Also, the long holes 320b, 320
d, 320e, the guide pin 100 of the main plate 100
b, 100d, and 100e are respectively inserted, and the second shutter blade 320 is inserted into the elongated holes 320b, 320d, and 320e.
It is movable in the direction of extension. Also, the main plate 100
The connecting pins 410 and 42 are provided at both ends of the supporting shaft 100f.
A link member 400 provided with a first shutter blade 310 is pivotally supported.
10f, and the connecting pin 420 is inserted into the long hole 320f of the second shutter blade 320. Further, a long hole 430 is formed in the link member 400 at a position deviated by a predetermined distance from the swing center (support shaft 100f), and the drive pin 41a is inserted into the long hole 430.

Then, as shown in FIG.
When a rotates substantially upward (the rotor 41 rotates clockwise), the link member 400 rotates counterclockwise, and the shutter blade 300 reaches the open position where the respective openings 310a and 320a open the opening 100a. The lower end of the first shutter blade 310 abuts against the stopper 100g and stops, and is positioned at that position. On the other hand, as shown in FIG. 10, when the drive pin 41a rotates substantially downward (the rotor 41 rotates counterclockwise), the link member 400 rotates clockwise, and the shutter blade 300 moves
10a and 320a reach the closed position where the opening 100a is completely closed, and the lower end of the second shutter blade 320 contacts the stopper 100h and stops, and is positioned at that position.

Further, as shown in FIG. 9, when the drive pin 41a is held at an intermediate position (the rotor 41 is held at an intermediate rotational angle position) by energizing the coil 42, the shutter blades 300 are respectively moved. Openings 310a, 320a
The opening portions 100a are held in a state of being narrowed down to a predetermined diameter by the edges 310a 'and 320a'. That is, the first shutter blade 310 and the second shutter blade 32
0 is the guide pin 1 in conjunction with the movement of the drive pin 41a.
00b, 100c, 100d, 100e
It reciprocates linearly so as to approach each other (moving in the direction toward the closed position) and separate from each other (moving in the direction toward the open position).

The diaphragm / shutter device according to this embodiment includes a control system (see FIG. 3) similar to that of the above-described embodiment as a control system for performing various controls, and a description thereof will be omitted. Also, the operation when the aperture / shutter device according to this embodiment is mounted on a digital still camera capable of capturing not only a still image but also a moving image,
As the shutter blade 300 reciprocates linearly,
Except that the aperture operation and the shutter operation for automatically reducing the aperture 100a to the optimal aperture are the same as those of the above-described embodiment, the description thereof is omitted.

Also in the aperture / shutter device according to this embodiment, when shooting a moving image, the aperture / shutter blade 300 is always driven and controlled so that the aperture aperture is optimally adjusted to the brightness of the subject light. Since such control is performed, a high-quality moving image can be captured. Further, when capturing a still image, since the optimal aperture operation has already been performed immediately before the release operation, it is only necessary to immediately move the shutter blade 300 serving also as the aperture to the closed position to perform the shutter operation. As compared with the case where the aperture operation is performed after the release operation, a time lag until the photographing is completed can be prevented, and quick imaging can be performed. Further, even when still images are continuously photographed, the speed can be increased.

In the above-described embodiment, two blades are employed as the shutter blades 30 and 300 which also serve as the aperture. However, the present invention is not limited to this.
Of course, it is also possible to employ a shutter blade composed of sheets. Also, a digital still camera capable of shooting moving images has been exemplified as a camera equipped with the aperture / shutter device, but the present invention is not limited to this, and a digital movie camera can also be used.

[0028]

As described above, according to the aperture / shutter device of the present invention, the shutter function for opening and closing the opening for exposure and the aperture function for narrowing the opening are performed by one aperture / shutter blade. And controlling the aperture operation of the shutter blades to have an optimal aperture sequentially according to the output signal of the detecting means for detecting the luminance of the subject light, so that the luminance with respect to the moving image that changes every moment is obtained. Is automatically and continuously performed without a step, so that a moving image or the like is captured with high image quality.

Also, prior to the release operation of the camera, the diaphragm operation for automatically setting the optimum aperture is automatically performed in advance, and the shutter blade is immediately moved to the closed position in response to the signal of the release operation. There is no time lag from the conventional aperture operation to the shutter operation, and high-speed shooting of a still image is possible. Further, since the aperture operation and the shutter operation are performed by one aperture / shutter blade, the size of the apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of an aperture / shutter device according to the present invention.

FIG. 2 is a cross-sectional view showing one embodiment of a diaphragm / shutter device according to the present invention.

FIG. 3 is a block diagram showing a control system of the aperture / shutter device according to the present invention.

FIG. 4 is a plan view showing a state in which an aperture / shutter blade forming a part of the aperture / shutter device of the present invention is in an open position where an opening is opened.

FIG. 5 is a plan view showing a state in which a shutter blade that also functions as a diaphragm, which is a part of the shutter device that also functions as an aperture stop according to the present invention, is at an aperture position where the aperture is narrowed to a predetermined diameter.

FIG. 6 is a plan view showing a state in which a shutter blade that also serves as a diaphragm, which is a part of the shutter device that also serves as the diaphragm of the present invention, is in a closed position where the opening is closed.

FIG. 7 is a time chart showing a control operation of the aperture / shutter device according to the present invention.

FIG. 8 is a plan view showing another embodiment of the aperture / shutter device according to the present invention, in which the aperture / shutter blade forming a part thereof is in an open position where an opening is opened. .

FIG. 9 shows another embodiment of the aperture / shutter device according to the present invention, in which the aperture / shutter blade forming a part thereof is in the aperture position where the aperture is narrowed to a predetermined aperture. It is a top view.

FIG. 10 is a plan view showing another embodiment of an aperture / shutter device according to the present invention, in which a shutter blade which also serves as an aperture is a closed position where an opening is closed. .

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Ground plate 20 Holding plate 30 Shutter blade also serving as diaphragm 31 First shutter blade, 32 Second shutter blade 40 Electromagnetic actuator (drive unit) 44 Magnetic pin, 45 Hall element 51 Control unit (control unit), 52 Motor drive control circuit 53 CCD, 54 CCD control circuit, 55 image signal processing circuit 56 photometer (detection means), 57 photometer circuit (detection means) 58 distance meter, 59 distance measurement circuit 60 main switch 61 release switch, 62 movie switch 100 base plate, 100a Opening 300 Shutter blade also serving as aperture 310 First shutter blade, 320 Second shutter blade 400 Link member 410, 420 Connecting pin, 430 Slot

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G03B 9/14 G03B 9/14 9/24 9/24 9/26 9/26

Claims (4)

[Claims] An aperture shutter blade movably provided between an open position for opening an exposure opening and a closed position for closing the exposure, and performing an aperture operation to make the opening a desired diameter. A driving unit for driving the shutter blades, a detecting unit for detecting the brightness of the subject light, and a control unit for controlling the driving unit, wherein the control unit automatically operates according to an output signal of the detecting unit. A shutter device for controlling the driving means so as to cause the shutter blades to perform an aperture operation to obtain an optimal aperture. 2. The control means causes the shutter blade to perform an aperture operation for automatically setting an optimum aperture according to an output signal of the detection means before a release operation of a camera,
Controlling the driving means so as to move the shutter blade to the closed position in response to a signal of a release operation;
2. The aperture / shutter device according to claim 1, wherein: 3. The shutter blade according to claim 1, wherein the shutter blade includes at least two blades provided so as to be rotatable around a predetermined axis so as to approach and separate from each other. The aperture / shutter device according to claim 1. 4. The aperture / shutter as claimed in claim 1, wherein said shutter blade comprises two blades which are linearly movable so as to approach and separate from each other. apparatus.