JPH04250434A - Half-open type shutter - Google Patents

Abstract

PURPOSE:To offer a half-open type shutter which makes the accurate control of plural diaphragms serve also as the interception of light. CONSTITUTION:This shutter is provided with a charging member 3 which abuts on a shutter blade driving member 7 whose action is regulated by the engagement of a pawl member 6 which moves by interlocking with the actuation of a control magnet 4, and moves the normal revolution of a motor 2 so as to open shutter blades 10 and 11 and returns to an initial position by the reverse revolution of the motor 2 after it reaches the specified position, and a signal generating means in accordance with the traveling position of the shutter blade. Therefore, both the accurate control of the plural diaphragms and the interception of the light beam are performed by one half-open type shutter.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a half-open shutter, and more particularly to a half-open shutter for a still video camera, and particularly for a camera whose image pickup device has an electric shutter function.

0002

2. Description of the Related Art In recent years, cameras having an electric shutter function have become commonplace due to improvements in solid-state imaging device technology. In order to reduce cost and miniaturize, it is thought that this technology could be used in the image sensor of still video cameras, and in order to cover a wide exposure range, it would be desirable to have not only a shutter function but also an aperture function. However, still video cameras have narrow exposure tolerances and require very high precision aperture control.

Therefore, as a conventional aperture mechanism, as shown in FIG. 5, an aperture disk 103 rotatably supported in the photographing optical path between a photographing lens 101 and an image sensor 102 has a plurality of holes corresponding to the diameter of the aperture. It has a claw part 103a, a locking protrusion 103b, and a gear part 103c corresponding to the plurality of holes on its outer periphery, and a charge pin 103d is erected on the surface thereof, and a spring 104 is used as shown in the figure. It is biased counterclockwise, and during charging, the tightening lever 105 is locked to the locking protrusion 103b, and a hole with an open aperture diameter is set for photographing light exposure.

When the release electromagnet 107 is energized, the operating lever 106 is attracted against the spring 106a and rotates clockwise in the figure, causing the tightening lever 105 to move against the spring 106a.
5a in the counterclockwise direction shown in the drawing,
03 from the locking protrusion 103b, and the aperture disk 103 engages with the gear portion 103c.
, and rotates clockwise by the force of the spring 104.

When the aperture disk 103 rotates to a position with a predetermined aperture diameter, a position signal is output from the printed circuit board 111 that comes into contact with the contact piece 110 fixed to the aperture disk 103, and is transmitted to the locking electromagnet 13. By applying electricity, the locking lever 112 is attracted against the bias of the spring 112b, and the locking lever 11
The second claw portion 112a engages with a predetermined one of the claw portions 103a of the aperture disk 103, the aperture disk 103 stops, and a predetermined aperture diameter is set.

When the photographing is completed, the charging motor 114 is driven by the completion signal, and the cam plate 117 is rotated via the gears 115 and 116 to rotate the charging lever 118 in the counterclockwise direction as shown in the figure. The aperture disk 103 is rotated clockwise against the biasing force of the spring 104, and the locking protrusion 103
A tightening lever 105 is engaged with b to hold the aperture disk 103 in the charging position.

[0007]

However, in the conventional example described above, if the number of types of apertures is increased in order to perform fine exposure control, the size of the aperture increases accordingly. Furthermore, when a CCD is used as the image sensor, recording is possible during field recording using the conventional aperture device and CCD electronic shutter, but when recording frames, CCD
When reading a CD signal, it is necessary to shield the CCD from light.

For this reason, there is a problem in that in addition to the aperture device of the conventional example, a mechanical shutter device such as a focal plane shutter is required.

The present invention is an attempt to solve the above-mentioned problems. That is, an object of the present invention is to provide a half-open shutter that can perform both highly accurate control of a plurality of apertures and blocking of light beams with a single shutter.

0010

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an electromagnetic device configured to open a shutter blade in conjunction with normal rotation of a motor and close the shutter blade by actuation of a control magnet. In the driven half-open shutter, a claw member that moves in conjunction with the operation of the control magnet;
A shutter blade driving member whose operation is regulated by engagement of the pawl member, and a shutter blade driving member that comes into contact with the shutter blade driving member and moves with normal rotation of the motor to open the shutter blade, and after reaching a predetermined position, the shutter blade is opened. It has a charging member that returns to the initial position when the motor reverses, and a signal generating means that generates a signal according to the traveling position of the shutter blade, and the output of the signal generating means causes the motor to rotate in the normal direction. The shutter blade is held in a predetermined opening by controlling the reverse rotation, and then the shutter blade is closed by actuation of the control magnet.

[0011]

[Operation] According to the present invention, there is a claw member that is interlocked with the operation of the control magnet, a shutter blade drive member whose operation is regulated by the engagement of the claw member, and a shutter blade drive member that comes into contact with the drive member to prevent the motor from rotating in the normal direction. A charge member that moves to open the shutter blade, and after reaching a predetermined position, engages the pawl member and the drive member by rotating the motor in reverse, keeping the opening of the shutter blade constant, and then returning to the initial position. and a signal generating means according to the running position of the shutter blade, and after holding the shutter blade at a predetermined opening by controlling forward and reverse rotation of the motor by the output of the signal generating means, By operating the control magnet, the claw member and the shutter blade drive member are disengaged and the shutter blades are closed, allowing highly accurate multiple aperture control and light beam blocking with a single half-open shutter. , you can do both.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an exploded perspective view showing a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a base plate that is the basic structure of the half-open shutter of the present invention, and an opening 1 through which light rays pass.
a, a shaft for holding various operating members described below, etc. are integrally constructed.

Reference numeral 2 denotes a motor capable of forward and reverse rotation as a driving source, and an output gear 2a for transmitting driving force is attached to the rotating shaft. 3 has a gear part 3e to which driving force is transmitted from the motor 2 through a gear train (not shown), and two shafts of the base plate 1 are inserted into the long groove parts 3a, and the shafts are inserted in the left and right directions in the figure. It is a charging member that is movably held by the projecting portion 3d, the tapered surface 3b, and the convex flat portion 3 having a length that is approximately equal to or longer than the length of the long groove portion 3a.
It has c.

Reference numeral 4 denotes an adsorption/detachment type control magnet. Reference numeral 5 designates a magnet lever rotatably held on the shaft portion of the base plate 1, which includes an armature 5a that is in close contact with the adsorption portion 4a of the control magnet 4, and a charge portion that is integrally constructed with the magnet lever 5 and has a spring property. 5b, a magnet spring 5c that detaches the armature 5a from the control magnet 4 when the control magnet 4 is de-energized, and is set to have a weaker adsorption/holding force than the control magnet 4 when the control magnet 4 is energized, and a claw of the claw member 6. An arm portion 5d that can come into contact with the claw member 6b, and when the control magnet 4 is not energized, contacts the claw member protrusion 6b and rotates the claw member 6 clockwise in the figure against the claw spring 6c. have.

Reference numeral 7 denotes a notch portion 7a which is rotatably held on the shaft portion of the base plate 1 and sets the aperture value of the aperture formed by the shutter blades 10 and 11 with which the claw portion 6a engages, and a shutter blade 10. , 11, and a gear portion 7c.

Reference numeral 8 denotes a gear portion 7 of the shutter blade driving member 7.
This is a pulse gear that is integrally configured with a pulse plate 8b that meshes with the pulse plate 8b at a gear portion 8a and has patterns of different light transmittances. Reference numeral 8c denotes a shutter spring that urges the pulse gear 8 clockwise in the figure, further urges the shutter blade drive member 7 counterclockwise, and holds the shutter blades 10 and 11 in a closed state.

Reference numeral 9 denotes a photointerrupter that converts changes in the pattern caused by rotation of the pulse plate 8b into electrical signals and detects the positions of the shutter blades 10 and 11. 10,
Reference numeral 11 indicates two shafts of the base plate 1 and long groove portions 10c and 11c.
The shutter blade drive member 7 slides in opposite directions to change the opening 1a of the main plate 1 from a closed state to a fully open state depending on the degree of overlapping of the openings 10a and 11a. It's a shutter blade.

The reference numeral 12 has an opening 12a for passing light rays in the same way as the opening 1a of the base plate 1, and a hole for holding each member constituting the half-open type shutter on the base plate 1 in a functional manner. It's a cover. 13 is a lens section for photographing, and 14 is an image pickup device such as a CCD for converting the image formed by the lens section into an electrical signal and recording it. 2 and 3 are explanatory diagrams of the operation of the half-open shutter shown in FIG. 1. FIG. 2(a) shows the initial state, and in FIG. 1, the shutter blades 10 and 11 are in a state where the opening 1a of the base plate 1 and the opening 12a of the cover 12 are blocked. When the motor 2 is rotated in the forward direction from this state, the charging member 3 is moved to the left in the figure via a gear train (not shown). Around this time, the control magnet 4 is energized.

After this, the tapered surface 3b of the charging member 3
pushes the charging part 5b downward in the figure. Therefore, the armature 5a is pressed against the attraction portion 4a of the control magnet 4, overcoming the force of the magneto spring 5c, and is attracted to the control magnet 4. Since the charging portion 5b has spring properties so that the armature 5a is reliably pressed against the control magnet 4, the height of the convex plane portion 3c of the charging member 3 is set to enable overcharging.

Next, the charging member 3 further moves to the left, the protrusion 3d contacts the abutting portion 7d of the shutter blade driving member 7, and the shutter blade driving member 7 is biased by the urging force of the shutter spring 8c. The pulse gear 8 is rotated clockwise in the figure, and at the same time the pulse gear 8 is rotated counterclockwise, causing the photointerrupter 9 to generate a pulse signal. At this time, since the shutter blade 10 moves to the right and the shutter blade 11 moves to the left, the opening 10 of the shutter blades 10 and 11
A, 11a form an aperture.

At this time, the claw member 6 successively engages with different locations along the notch portion 7a of the shutter blade drive member 7. This is the state shown in FIG. 2(b). Here, the photointerrupter 9 determines when the aperture opens slightly larger than a predetermined aperture value calculated from the output of a photometer (not shown), that is, when the claw portion 6a crosses the predetermined notch portion 7a. When detected by the pulse signal, the motor 2 is reversed and the charging member 3 is returned to its initial position. Then, the claw portion 6a of the shutter blade drive member 7 remains engaged, and a predetermined aperture is set. This is the state shown in FIG. 2(c).

Thereafter, appropriate exposure is performed using a combination of the electronic shutter of the image pickup device 14 such as a CCD and the set aperture value. That is, during field recording, the half-open shutter of the present invention functions only as an aperture, and exposure is performed by the electronic shutter. At this time, by continuously operating the electronic shutter and recording each time from the image sensor 14 on a recording medium such as a floppy disk (not shown), it is possible to easily perform not only frame photography but also continuous photography.

After exposure and photographing by the electronic shutter are completed, the power to the control magnet 4 is cut off, the magnet lever 5 rotates counterclockwise in the figure, and the arm 5d pushes the claw protrusion 6b. , rotate the claw member 6 clockwise, and
a from the notch portion 7a. Therefore, the shutter blade driving member 7 is driven by the pulse gear 8 by the shutter spring 8c.
The shutter blades 10, 1 are rotated counterclockwise through the
1 is returned to its initial state, that is, the state shown in FIG. 2a, the openings 1a and 12a are closed, and the exposure is completed. Further, the electric signal of the photographed image stored in the image sensor 14 is recorded on a recording medium such as a floppy disk (not shown), and the series of photographing operations is completed.

FIG. 3 is a timing chart showing the above operation, and the timings of FIGS. 2(a), 2(b), and 2(c) are respectively changed to (a), (b), and (c). It is shown in Immediately before the image sensor 14 is driven, during both field and frame shooting, the charge that has accumulated in the element 14 up to that point is cleared, so that the aperture aperture setting of the shutter can be set accurately. Even if there is some unevenness in the time it takes to set the aperture aperture, there is no problem.

FIG. 4 is an exploded perspective view showing a second embodiment of the present invention. In this second embodiment, a brush 15 fixed to a shutter blade drive member 7 and the drive member 7 are used instead of the pulse gear 8, photo interrupter 9, etc. of the signal generating means in the first embodiment described above. The rotational phase of the shutter blade drive member 7 is controlled by sliding contact with the shutter spring 15a (which acts in the same manner as the shutter spring 8c in the first embodiment) and the brush 15, which biases the shutter blade in the middle and counterclockwise directions. The absolute positions of the shutter blades 10 and 11 are configured to be detectable by an encoder 16 for outputting as an absolute value signal.

With the above configuration, the overall sequence is the same as the first embodiment described above, but the absolute position of the shutter blade is not affected by the backlash of the gear.
It becomes possible to control the control magnet 4 more accurately.

[0027]

[Effects of the Invention] As explained above, according to the present invention,
In an electromagnetically driven half-open shutter, there is a pawl member that moves in conjunction with the operation of a control magnet, a shutter blade drive member whose operation is regulated by the engagement of the pawl member, and a shutter blade drive member that contacts the shutter blade drive member and controls the motor's rotation. The charging member has a charge member that rotates to open the shutter blade and returns to the initial position by reversing the motor after reaching a predetermined position, and a signal generating means that generates a signal corresponding to the traveling position of the shutter blade. , and is configured to control forward and reverse rotation of the motor by the output of the signal generating means to hold the shutter blade at a predetermined opening, and then close the shutter blade by actuation of the control magnet. Because of this, it is possible to set the aperture diameter to maximum maximum or multiple aperture values with high precision, and since it has a function as a shutter, by using it in conjunction with the electric shutter function of the image sensor, it is possible to set the aperture diameter to maximum aperture value or to multiple aperture values. During frame recording, only the aperture and closing side need to function as a shutter, which has the effect of making it easier to achieve accuracy.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing changes in the operation of the half-open shutter in FIG. 1;

FIG. 3 is an explanatory diagram showing the timing of the operation of the half-open shutter in FIG. 1;

FIG. 4 is an exploded perspective view showing a second embodiment of the present invention.

FIG. 5 is a perspective view showing an example of a conventional technique.

[Explanation of symbols]

1...Main plate 2
…Motor 3…Charging member 4
...Control magnet 5...Magnet lever
6... Claw member 7... Shutter blade drive member 8... Pulse gear 9... Photo interrupter 10, 11... Shutter blade 12... Cover
13...Lens section 14...Image sensor
15...Brush 16...Encoder

Claims (1)

[Claims] 1. An electromagnetic drive half-open shutter configured to open a shutter blade in conjunction with forward rotation of a motor and close the shutter blade in response to operation of a control magnet, wherein the shutter operates in conjunction with operation of the control magnet. a pawl member, a shutter blade drive member whose operation is regulated by engagement of the pawl member, and a shutter blade drive member that comes into contact with the shutter blade drive member and moves by normal rotation of the motor to open the shutter blade and reach a predetermined position. a charging member that returns to the initial position by reversing the motor after the motor is rotated, and a signal generating means that generates a signal corresponding to the traveling position of the shutter blade, and the output of the signal generating means causes the motor to be activated. A half-open type shutter, characterized in that it has a control means that controls normal rotation and reverse rotation to hold the shutter blade at a predetermined opening, and then controls the shutter blade to close by operating the control magnet.