JPH11133482A - Shutter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely open a shutter to perform exposure by adjusting a reference position to a position where a specified minimum diameter aperture is obtained by shutter blades. SOLUTION: In order to realize exposure control to the upper limit value of an original exposure value, the shutter blades 31 and 32 start sliding movement in an opening direction, and time from the point of time when they reach the reference position is measured, and a driving signal is stopped at the point of time when the time corresponding to the exposure value elapses. As for the upper limit value of the exposure value, the aperture is obtained even when the driving signal is stopped as soon as the blades 31 and 32 reach the reference position. The reference position is decided considering the moving speed of the blades 31 and 32 and responsiveness obtained until the blades 31 and 32 start the sliding movement in the closing direction from the stop of the driving signal. Even when the driving signal is stopped (a shutter closing signal is generated) as soon as the blades 31 and 32 which are moving in the opening direction reach the reference position, the regulated minimum diameter aperture is adjusted at a position formed by the blades 31 and 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shutter device used for a camera.

[0002]

2. Description of the Related Art Some compact cameras and instant cameras use a program shutter in which an aperture blade is used also as a shutter blade. In this programmed shutter, exposure is performed using a combination of a predetermined aperture value and shutter speed for each exposure value. Generally, two or more shutter blades are combined, and these are simultaneously operated by an actuator such as a motor or a solenoid. Open and close.
In such a programmed shutter, the opening time of the shutter blade is determined in accordance with the exposure value, and the opening diameter of the shutter blade corresponding to the aperture value is increased or decreased according to the amount of movement of the shutter blade determined by the opening time. This is a general and convenient method.

FIG. 15 shows a state in which a program shutter is driven by a conventional control method. A change in the movement position (amount) of the shutter blade over time is represented by a characteristic curve S.
It is represented as 4. Note that the movement position D0 is the position of the shutter blade at which the opening of the opening is started by the shutter blade. When the EV value is calculated by photometry, the opening time T ₀ is uniquely determined correspondingly. When a trigger signal is given by the shutter release operation and, for example, the motor starts rotating forward, the shutter blades move in the opening direction. Further, the motor is counting the open time from the time of starting the normal rotation T ₀ is started.

When the amount of movement of the shutter blade increases and reaches the movement position D0, the shutter blade starts forming an opening, and the diameter of the opening increases as the amount of movement further increases. Then, when the timing of the opening time T ₀ is completed, a shutter closing signal is generated. In response to the shutter closing signal, the motor starts to rotate in the reverse direction, the shutter blades that have been moving in the opening direction move in the closing direction, return to the closing position, and one exposure operation is completed. Immediately after the shutter close signal is generated, the shutter blades move in the opening direction due to the influence of inertia and the like, and the exposure is continued even while the shutter blades are closing. T ₀ is determined. According to the above, various exposure amounts can be obtained only by determining the opening time T ₀ corresponding to the EV value, and the configuration is relatively simple.

[0005]

By the way, in the shutter device of the above-mentioned control system, there is no problem as long as the shutter blades always move under the same condition. However, actually, for example, when the photographing posture of the camera is changed, The operating state when the shutter blades are opened and closed due to changes in the frictional force between the shutter blades, and between the shutter blades, and between the shutter blades, individual differences and aging of the shutter blades, changes in the surrounding environment, responsiveness of the actuator, and the like. Is easy to fluctuate. In particular, at the start of the operation in which the shutter blade starts moving in the opening direction, the shutter blade is changed from the stationary state to the moving state, so that the operation start timing and the moving speed at that time tend to fluctuate.

For example, when the operation start timing of the shutter blade is started or the moving speed is slowed, a characteristic curve S5 shown in FIG. 15 is obtained. For the shutter blade operating with such a characteristic curve S5,
When performing exposure with opening time T ₀ corresponding to the EV value obtained by the photometric, it can be seen that the underexposed compared to the case of performing exposure under the curve S4. In the worst case, as shown by the characteristic curve S6, a phenomenon occurs in which the shutter blade starts moving in the closing direction without forming an opening. This phenomenon is more likely to occur especially when the luminance of the subject is high. This is because the subject brightness in the case of high brightness, by shortening the time T ₀ opened in order to reduce the aperture diameter, to reduce the amount of movement of the shutter blade. As a result, there is a problem that the photographing is completed without opening the shutter and the exposure is not performed by the photographing. In order to prevent the occurrence of this phenomenon, it is sufficient to provide a margin so that the opening is formed without making the opening time T ₀ shorter than a certain time. Will invalidate the exposure control.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and has as its object to provide a shutter device that can reliably open a shutter and perform favorable exposure.

[0008]

According to a first aspect of the present invention, there is provided a shutter device, wherein a shutter closing signal is generated when an opening time corresponding to an exposure value determined according to a subject luminance is reached. When the shutter blade moves to the closing direction by controlling the driving of the actuator, the reference position of the shutter blade for starting the timing of the opening time is such that the shutter blade reaches this reference position. At the same time when the shutter closing signal is generated, a position at which the shutter blade can obtain an opening having at least a minimum opening diameter within a predetermined range in which the opening diameter of the opening obtained by opening and closing movement of the shutter blade is changed. It is adjusted.

According to a second aspect of the present invention, the actuator is a motor, and the rotary shaft of the motor is directly connected to a driving member connected to the shutter blades for opening and closing the shutter blades, and the shutter blades are connected to the motor by the motor. It is designed for direct drive. Claim 3
The described shutter device includes a speed adjusting mechanism for reducing the moving speed of the shutter blade in the opening direction.

[0010]

FIG. 2 shows an instant camera incorporating a shutter device according to the present invention. The camera body 10 is provided with a viewfinder 11, a strobe light emitting unit 12, a lens barrel 14 holding a taking lens 13, and the like. The lens barrel 14 incorporates an extension mechanism for extending the photographing lens 13 according to the photographing distance to the subject, a shutter device of the present invention, and the like. Also, on the front surface of the lens barrel 14, a distance measuring light emitting window 15 and a distance measuring light receiving window 16 for autofocus, a light measuring window 17 for measuring subject brightness, and a light amount of strobe light are measured. And a strobe light metering window 18 are provided.

In the camera body 10, a film pack storage chamber (not shown) is formed on the back side, and a film pack in which a plurality of mono-sheet type film units 20 are stacked in the film pack storage chamber. Will be loaded. When the photographing is performed by pressing the release button 22 provided on the grip portion 21, the uppermost exposed film unit 2 of the laminated film units 20 is exposed.
0 is discharged from the discharge port 23 on the upper part of the camera body 10. At the time of this discharge, the film pod 20 of the developing solution pod 20a is torn by a pair of developing rollers provided in the discharge port 23, and the developing solution built in the developing solution pod 20a is spread. Is discharged from As a result, the development processing necessary for the film unit 20 is completed, and a print photograph is obtained after a lapse of a predetermined time.

As shown in FIG. 3, the shutter device comprises a photometric unit 60 for measuring the luminance of the subject, and a controller for controlling the driving of the actuator in accordance with the luminance of the subject from the photometric unit 60 to control the opening and closing of the shutter blades. 70.

Behind the taking lens 13, behind the taking lens 1
An exposure opening 30 is provided for guiding the photographing light from 3 to the film pack storage room. In order to open and close the exposure opening 30, two shutter blades 31 and 32 which are also used as aperture blades are used. These shutter blades 31 and 32 are provided with guide portions 31a and 32a, respectively.
The blades 31b and 32b cover the exposure opening 30, and the blades 31b and 32b are formed with opening forming portions 31c and 32c cut out in a substantially "V" shape. Each of the shutter blades 31 and 32 is
A guide pin 35a is passed through a guide hole 35 formed elongated in 1a and 32a, so that the guide pin 35a is slidable in the left-right direction in the figure.

The rotating lever 37 has arms 37a and 37b and is rotatable about a shaft 37c. The connecting levers 38a and 38b provided at the ends of the arms 37a and 37b are connected to the guide portions 31a and 32a.
Are connected to the shutter blades 31 and 32 by being fitted into connection holes 41 and 42 provided at one end of the shutter blades 31 and 32, respectively.
A plunger 45a of a solenoid 45 as an actuator is connected to one arm 37b of the rotating lever 37 by a connecting plate 4a.
6, the other arm 37a is provided with, for example, one end of a coil spring 47, and the rotating lever 37 is urged in the counterclockwise direction in the figure by the coil spring 47.

The solenoid 45 is driven by a driver 48 controlled by a controller 70. Driver 4
8, a drive current is supplied to the coil portion 45b of the solenoid 45 while the drive signal is being input from the controller 70. When a drive current flows, the solenoid 45 draws the plunger 45a into the coil portion 45b, thereby rotating the rotating lever 37 clockwise in the figure against the bias of the coil spring 47.

By the clockwise rotation of the rotating lever 37, one shutter blade 31 slides rightward in the drawing and the other shutter blade 32 slides leftward in the drawing, and each blade portion 31b, 32b opening forming portions 31c, 32
c overlaps the front surface of the exposure opening 30 to form an opening. Then, the opening diameter formed by increasing the amount of sliding movement of the shutter blades 31 and 32 in the opening direction increases.

When the drive signal is stopped and the drive current is interrupted, the rotating lever 37 is rotated counterclockwise by the urging force of the coil spring 47 while pulling out the plunger 45a from the coil portion 45b. This rotating lever 37
Of the shutter blades 31 and 32 by the counterclockwise rotation of
Respectively slide in the closing direction opposite to the opening direction, and the respective blade portions 31b and 32b overlap to expose the exposure opening 30.
Close. In this example, the stop of the drive signal is a shutter close signal. Also, due to the responsiveness of the solenoid 45 and the inertia of the rotating lever 37 and the shutter blades 31 and 32, the shutter blades 31 and 32 start sliding in the closing direction with a delay from the moment the drive signal is cut off.

In this shutter device, the shutter blades 31 and 32 are opened in the opening direction so as to prevent the inconvenience that the exposure is not performed without opening the shutter and to enable the exposure control to the upper limit of the original exposure value. The slide movement is started, and the time from when the reference position described in detail below is reached is measured.When the time corresponding to the exposure value has elapsed, the drive signal is stopped, and the upper limit value of the exposure value is determined. The opening is obtained even when the drive signal is stopped at the same time when the shutter blades 31 and 32 reach the reference position.

To detect that the shutter blades 31 and 32 have reached the reference positions, a projection 50 and a photo interrupter 51 are provided. The protruding portion 50 is formed so as to protrude in a rectangular shape at an upper edge portion of one of the shutter blades 31, and the photo interrupter 51 has a light receiving portion and a light projecting portion arranged so as to sandwich a pass area of the protruding portion 50.

Before the shutter blades 31 and 32 start sliding in the opening direction, the protrusion 50 is located between the light receiving portion and the light projecting portion of the photo interrupter 51, that is, at the detection position 51a. By setting the left side 50a of the protrusion 50 in the figure at the detection position 51a when the reference numeral 32 reaches the reference position, the photoelectric signal from the photointerrupter 51 is changed from "L level" to "H".
Level. The change of the photoelectric signal from “L level” to “H level” is a reference position detection signal indicating that the shutter blades 31 and 32 have reached the reference positions. The reference position detection signal is sent to the controller 70, and is used to start time measurement until the drive signal is stopped.

The above-mentioned reference positions are the positions of the shutter blades 31, 3
2, the shutter blades 31,
Responsiveness (hereinafter, these are collectively referred to as operation characteristics) until the slide blade 32 starts sliding in the closing direction is determined in consideration of the shutter blades 31, 31 moving in the opening direction.
Even when the drive signal is stopped (shutter close signal is generated) at the same time when the shutter 32 reaches the reference position, the opening having at least the defined minimum opening diameter is adjusted to the position formed by the shutter blades 31 and 32.

More specifically, shutter blades 31, 32
At the moment when the sliding movement of the shutter blades changes from the opening direction to the closing direction, the maximum opening diameter in a series of shutter opening / closing operations is obtained.
When the moving speed of the shutter blades 1 and 32 is the slowest,
Even if the drive signals are stopped at the same time when the drive signals 1 and 32 reach the reference position, the reference position is adjusted so that the maximum opening diameter in this series of shutter opening and closing operations becomes the defined minimum opening diameter. Note that the minimum aperture diameter is determined by the shutter blade 3 determined corresponding to the exposure time determined for each exposure value.
This is the smallest one of the aperture diameters corresponding to the aperture value formed by the apertures 1 and 32.

In this example, the plunger 45a and each shutter blade 3 due to the difference in the photographing posture of the instant camera
The variation of the operating characteristics is based on the difference in the direction of action of gravity on the first and the second, the variation of the frictional force between the shutter blades, the influence of temperature and humidity within a predetermined range, the degree of the temporal change within a certain range, and the like. The reference position which is obtained experimentally and meets the above condition is adjusted under the variation of the operation characteristics. Then, for example, as shown in FIG. 4, a position where each of the opening forming portions 31c and 32c overlaps to form a pinhole while each of the shutter blades 31 and 32 slides in the opening direction is set as a reference position. The side 50 a of the projection 50 is made to face the detection position 51 a of the photosensor 51. Of course, this reference position is an example, and the reference position changes depending on the variation in the operation characteristics.

It should be noted that if the phenomenon that exposure is not performed is simply prevented by simply forming an opening regardless of whether or not the minimum opening diameter is formed, one of the protrusions 50 may be used. Side 50a and detection position 51 of photo sensor 51
By changing the positional relationship with “a”, the position at the time when the shutter blades 31 and 32 start forming the openings as shown in FIG. 5 may be set as the reference position. With this configuration, even if the drive signal is stopped at the same time when the reference position is reached, the shutter blades 31,
An opening is formed by the shutter blades 31 and 32 slidingly moving in the opening direction by inertia of the rotation lever 32, the rotating lever 37, the plunger 45a, and the like. When the reference position is simply adjusted as described above, the reference position may be a position advanced from the position at the time when the shutter blades 31 and 32 start forming an opening. The start of the slide movement is only delayed, and considering that the exposure amount does not become excessive, the reference position should be set to a position where the minimum opening diameter is formed at the maximum.

The structure for detecting that the shutter blades 31 and 32 have reached the reference position is not limited to the above-mentioned structure as long as the position or the amount of movement of the shutter blades can be detected. Good to do. Also, instead of directly detecting the position of the shutter blade 31, the shutter blades 31, 32 are indirectly detected, for example, by detecting the position or the amount of movement of the plunger 45a or the rotary lever 37 connected to the shutter blade. May have reached the reference position.

The photometer 60 comprises a light receiving element 60a and a luminance conversion circuit 60b. Light receiving element 60a
Is provided behind the photometric window 17, receives the subject light from the subject, and outputs a photoelectric signal proportional to the intensity of the subject light, that is, the subject brightness, to the brightness conversion circuit 60b. The brightness conversion circuit 60b outputs the subject brightness LV based on the photoelectric signal from the light receiving element 60a. The obtained subject brightness LV is sent to the controller 70.

The controller 70 includes an arithmetic circuit 71, a timer 72, and a drive signal generation circuit 73. Each time the release button 22 is pressed, the arithmetic circuit 71 receives a release signal from a microcomputer that controls the shooting sequence, captures the subject brightness LV that is being input at that time, and obtains the subject brightness LV.
Then, an exposure value EV corresponding to the subject luminance LV is calculated from the film sensitivity of the film unit 20 loaded in the camera. Then, a timer time T as an open time determined with respect to the obtained exposure value EV is obtained by using a conversion table, this is set in the timer 72, and a trigger signal is generated. Send to The arithmetic circuit 71 receives a reference position detection signal from the photo interrupter 50 and sends a timer start signal to the timer 72 at the moment the reference position detection signal is input.

The conversion table of the arithmetic circuit 71 divides the entire range of the exposure value EV for which exposure control can be set in advance into appropriate steps, and associates a specific timer time T with each exposure value EV. It has become. The timer time T is the time from when the shutter blades 31, 32 slide in the opening direction to reach the reference position until a shutter closing signal for moving in the closing direction is generated (in this example, the driving signal is Time to stop)
When a series of opening / closing operations are performed, it is determined that an approximately appropriate exposure amount corresponding to the corresponding exposure value EV can be obtained. Then, “0” is given to the timer time T corresponding to the upper limit of the range of the controllable exposure value EV in order to perform exposure with the specified minimum opening diameter, and from this upper limit, the exposure value EV is reduced. The timer time T is set to increase as the value decreases. In the case where the exposure value EV exceeds the upper limit value, the timer time T (=
"0").

Since the operating characteristics of the shutter blades 31 and 32 vary, even if each timer time T of the conversion table corresponding to each exposure value EV is determined based on any operating characteristic, the exposure amount is not small. Occurs. For this reason, the timer time T other than “0” is determined according to, for example, the operation characteristics of the shutter blades 31 and 32 which are frequently used, so that an optimal exposure amount can be obtained in many cases. By determining the timer time T according to an intermediate operation characteristic in the range of the characteristic variation, it is preferable that the variation of the exposure amount falls within a certain range centered on the appropriate exposure amount.

The timer 72 starts counting from the point in time when the timing start signal is input from the arithmetic circuit 71, and generates a stop signal at the moment when the time to be counted reaches the set timer time T. It is sent to the drive signal generation circuit 73,
If the set timer time T is “0”, a stop signal is sent when the timer time T is set. The drive signal generation circuit 73 generates a drive signal when a trigger signal from the arithmetic circuit 71 is input, and stops the drive signal when a stop signal from the timer 72 is input. As a result, the drive signal generation circuit 73 generates a drive signal between the time when the shutter blades 31 and 32 reach the reference position and the time when the timer time T elapses, and generates the drive signal when the timer time T elapses. Stop. This drive signal is sent to the driver 48.

In this way, the shutter blades 31, 32
Starts moving in the opening direction, and stops the drive signal based on the time when the timing is started when the reference position is reached, so that the timing of starting movement of the shutter blades 31 and 32 in the opening direction can be improved. In addition, the influence of the variation in the moving speed of the shutter blades 31 and 32 in the initial stage of the movement on the opening diameter of the openings formed by the shutter blades 31 and 32 is minimized.

Next, the operation of the above configuration will be described with reference to FIG. In FIG. 1, the shutter blades 31 and 32 operating at the design operation start timing and the moving speed are shown.
Are represented by reference symbol S0, and reference symbols S1, S2
Are the worst case characteristic curves within the range of the variation of the operating characteristics considered when adjusting the reference position. The characteristic curve S1 indicates the case where the operation start timing is delayed and the moving speed is slower than the standard characteristic curve S0, and the characteristic curve S2 indicates that the operation start timing is faster and the moving speed is lower than the standard characteristic curve S0. Represents the case where the speed is fast.

Framing is performed with the film pack loaded, and the release button 22 is pressed to take a picture. By being framed, the photometric unit 60
Represents the subject brightness L according to the intensity of the subject light
V is output to the arithmetic circuit 71. On the other hand, when the release button 22 is pressed, the microcomputer
The release signal is sent to the arithmetic circuit 71.

The operation circuit 71 is operated by the release signal.
Captures the subject brightness LV output from the photometric unit 60, calculates the exposure value EV from the subject brightness LV and the film sensitivity of the film unit 20, and calculates the exposure value EV.
Is converted to a timer time T using a conversion table. For example, if the subject brightness is high and the obtained exposure value EV is the upper limit value, the exposure value EV is converted into a timer time T of “0”, and this is set in the timer 72. Thereafter, the arithmetic circuit 71 sends a trigger signal to the drive signal generation circuit 73.

Upon receiving the trigger signal, the drive signal generation circuit 73 starts (ON) the generation of the drive signal, and the driver 4
A drive current is supplied to the solenoid 45 through the solenoid 8. Then
The plunger 45a is retracted into the coil portion 45b, and the rotation lever 37 starts rotating clockwise in FIG. 3 against the bias of the coil spring 47. This rotating lever 37
, The shutter blades 31, 32 connected to the arms 37a, 37b of the rotating lever 37 slide in the opening direction.

As the amount of retraction of the plunger 45a increases and the rotation angle of the rotation lever 37 increases,
The amount of sliding movement of the shutter blades 31, 32 in the opening direction also increases. Then, when the shutter blades 31 and 32 reach the movement position D0, the opening forming portions 31c and 32c of the shutter blades 31 and 32 overlap, and thereafter, as shown in FIG. 1, the side 50 a of the projection 50 faces the detection position 51 a of the photo interrupter 51, and a reference position detection signal is sent from the photo interrupter 51 to the arithmetic circuit 71.

When the reference position detection signal is input, the arithmetic circuit 71 sends a clock start signal to the timer 72 at that moment. Then, at this instant, the timer 72 starts measuring time. However, since the set timer time T is “0”, the moment the timer start signal with the set timer time T is input, that is, the reference position detection signal Is generated at the same time as the occurrence of the stop signal, and is sent to the drive signal generation circuit 73.
The drive signal generation circuit 73 stops (OFF) the drive signal simultaneously with the input of the stop signal. As a result, the drive current from the driver 48 is cut off by the solenoid 45.

When the driving current of the solenoid 45 is cut off, the rotation lever 37 does not receive a clockwise rotation force from the solenoid 45, and will be rotated counterclockwise by the bias of the coil spring 47. However, due to the inertia of the rotating lever 37, the plunger 45a, and the shutter blades 31, 32, the rotation is not immediately started. Therefore, the shutter blades 31 and 32 do not start sliding in the closing direction at the moment when the drive current is interrupted. Some time after the drive current is cut off, the rotating lever 37 starts rotating counterclockwise by the bias of the coil spring 47, and the shutter blades 31, 32 start sliding in the closing direction. The plunger 45a is pulled out of the coil part 45b by the rotation of the rotation lever 37.

In this way, the shutter blades 31, 32
At the moment when the direction of the slide movement is changed from the opening direction to the closing direction, an opening having the maximum opening diameter for this series of opening and closing operations is formed on the front surface of the exposure opening 30. And the reference position is
Since the maximum opening diameter during a series of opening and closing operations is adjusted to be at least the minimum opening diameter in consideration of the variation in the operating characteristics, the operation considered when the shutter blades 31, 32 adjust the reference position. If the operation is performed within the range of the characteristic variation, the characteristic curve S1 or the characteristic curve S1
As shown at 0 and S2, the slide movement in the closing direction is started at the same time as the movement position D2 at which the opening having the minimum opening diameter is formed or after the sliding movement in the opening direction. As a result, as shown in FIG. 6, the shutter blades 31 and 32
An opening having at least a minimum opening diameter is formed by 1c and 32c.

Thereafter, the shutter blades 31 and 32 are slid in the closing direction to gradually reduce the opening diameter. When the shutter blades 31, 32 pass through the movement position D0 during the sliding movement in the closing direction, the exposure openings 30 are completely closed by the shutter blades 31, 32.

In this manner, the shutter blades 31 and 32 are opened and closed when the exposure value EV is the upper limit value, and while the shutter blades 31 and 32 form an opening, the exposure is performed through this opening. The film unit 20 is exposed by subject light passing through the opening 30. When the opening and closing operations of the shutter blades 31 and 32 are completed and the exposure is completed, the exposed film unit 20 is discharged from the instant camera.
During this discharge, the developer pod 20a of the film unit 20 is torn open, and the developing process using the developing solution contained in the developer pod 20a is completed. After a predetermined time has elapsed, a print photograph is obtained. This print photo is
At the time of exposure, since the shutter blades 31 and 32 form openings with at least the minimum opening diameter, no image is not shown.

Further, in this way, the opening having at least the minimum opening diameter is formed even with the timer time T of "0", corresponding to the upper limit of the original exposure value EV that can be handled by the shutter device. It can be understood from the fact that the upper limit of the actual exposure value EV does not need to be set lower than the original upper limit of the corresponding exposure value EV in accordance with the variation in the operation characteristics of the shutter blades 31 and 32. Exposure can be controlled even in a high brightness range of the subject, although some variation in the exposure amount occurs.

When the exposure value EV corresponding to the subject brightness exceeds the upper limit value, the shutter blades 31 and 3 are set at the timer time T of "0" similarly to the case where the exposure value EV is the upper limit value.
2 is performed. In this case, it goes without saying that the overexposure occurs as the subject luminance increases. If the exposure value EV corresponding to the subject brightness is smaller than the upper limit value, a finite timer time T (> 0) corresponding to the exposure value EV is set to the timer 7.
After being set to 2, a drive signal is generated, and the shutter blades 31, 32 are slid in the opening direction. And
When the set timer time T elapses after the shutter blades 31 and 32 reach the reference position, the drive signal is stopped, and the shutter blades 31 and 32 slide in the closing direction with a delay from the stop of the drive signal. Moving. Thus, the shutter blades 31 and 32 expose the film unit 20 to the exposure time and the aperture diameter corresponding to the exposure value EV in a series of opening and closing operations.

FIGS. 7 and 8 show an example in which the opening and closing operations of the shutter blades are performed by a direct drive system using a motor. Note that portions other than those described in detail below are the same as those in the above-described embodiment. Components having substantially the same functions are denoted by the same reference numerals as those in the above-described embodiment, and description thereof is omitted.

In FIG. 7, a shutter blade 3 is provided on the rear side of the shutter substrate 80 on which the guide pins 35a and the like are formed.
1, 32, rotating lever 37, photo interrupter 51,
The mask plate 81 in which the exposure opening 30 is formed is assembled. Each of the shutter blades 31 and 32 is slid in the opening direction (the direction of the arrow in the drawing) and the closing direction opposite to the opening direction by the rotation of the rotation lever 37.

The center of the torsion spring 82 is passed through a pin 83 formed on the rotation lever 37, one end of which is hung on the shaft 37c of the rotation lever 37, and the other end of which is the shutter blades 31, 32. Are connected to the connection holes 41 and 42.
Each of the shutter blades 3 is formed by these torsion springs 82.
1 and 32 connect the inner periphery of the connection holes 41 and 42 to the connection pins 3.
8a, 38b to be pressed against
The rotation lever 37 is connected so that there is no play.

As shown in FIG. 8, on the front side of the shutter substrate 80, a motor 84 as an actuator for opening and closing the shutter blades 31, 32 and a slow speed mechanism 8 are provided.
5 is assembled. As the motor 84, a moving magnet type motor including a rotor 86 made of a permanent magnet and a stator 87 having stators 87a and 87b is used.

The rotor 86 is integrally provided with a rotating shaft 86a. The rotating shaft 86a is connected to the shaft 37 of the rear rotating lever 37 through a hole formed in the shutter substrate 80.
c. A motor-side lever 88, which is a part of a clutch mechanism connected to the rotating shaft 86a and the speed adjusting mechanism 85, is fixed to the rotating shaft 86a. Stator part 87
Is wound with a coil 87c, and a rotor 86 is rotated by a predetermined angle by passing a drive current through the coil 87c.

When a drive current is applied so as to apply a positive voltage to one terminal of the coil 87c, as shown in FIG. 9 (a), one stator 87a becomes an N pole and the other stator 87b becomes an S pole. , Rotor 86 rotates to a fully open rotation position where its south pole is closer to one stator 87a. When a driving current in the opposite direction is applied to the coil 86b, the stators 87a and 87b are turned off as shown in FIG.
The rotor 86 rotates clockwise in FIG. 9 from the fully open rotation position, and its north pole rotates to the closed rotation position near one stator 87a.

When the rotor 86 is in the closed rotation position, the exposure opening 30 is closed by the shutter blades 31 and 32 connected via the rotation shaft 86a and the rotation lever 37, and
When the rotor 86 is rotated from the closed position to the fully opened rotation position, the shutter blades 31 and 32 slide in the opening direction, and when the rotor 86 is rotated to the fully opened rotation position, the exposure opening 30 is fully opened.

As described above, the motor 84 is directly connected to the rotating lever 37 as a driving member connected to the shutter blades 31 and 32, and the shutter blades 31 and 32 are directly driven, whereby the shutter blades 31 and 32 are driven. , 3
The mechanism for performing the opening / closing operation 2 can be simplified. Also, the shutter blades 31, 32 can be formed with a small number of members.
Is opened and closed, the inertia of the members connected to the motor 84 can be reduced, and the shutter blades 31 and 32 can be opened and closed.
Responsiveness when turning from the opening direction to the closing direction can be improved.

As shown in FIG. 8, the shutter substrate 80
A flywheel 90 having a large mass and a wheel-side lever 91 are pivotally mounted on the front surface of the vehicle. A torsion spring 92 is attached to the flywheel 90. This torsion spring 92 has one end 92 a thereof at the shutter substrate 80.
The other end 92b is hooked on a groove 90a formed on the front surface of the flywheel 90, and urges the flywheel 90 in the direction of the arrow in the figure. A gear 93 (see FIG. 10) is integrally provided on the rear side (shutter substrate side) of the flywheel 90.

The wheel-side lever 91 has a sector gear 91a at one end thereof which meshes with the gear 93 of the flywheel 90.
The other end is provided with a receiving portion 91b which forms a clutch mechanism together with the motor-side lever 88 and engages with the motor-side lever 88. The wheel-side lever 91 is engaged with the sector gear 91a and the gear 93 by inserting a pin 91c (see FIG. 10) formed on the rear side of the wheel-side lever 91 into a guide groove 94 provided in an arc shape on the shutter substrate 80. Can be swung within a range where is not released.

FIG. 10 shows a state of the flywheel 90, the wheel-side lever 91, and the motor-side lever 88 when the rotor 86 of the motor 84 is in the closed rotation position. Since the sector gear 91a meshes with the gear 93 of the flywheel 90, the wheel-side lever 91 is urged clockwise by a torsion spring 92 via the gear 93, and the wheel-side lever 91 is , Rotor 86
Is in the closed rotation position, the receiving portion 91b is at the initial position where it contacts the pressing portion 88a of the motor-side lever. Since the swing range of the wheel-side lever 91 is regulated by the guide groove 94, the wheel-side lever 91 is not swung by the motor-side lever 88 so as to rotate the rotor 86 at the closed rotation position.

When the shutter blades 31, 32 are slid in the opening direction, when the rotation shaft 86a of the motor 84 rotates, the motor-side lever 88 rotates counterclockwise. At this time, the motor-side lever 88 presses the receiving portion 91b with the pressing portion 88a, and swings the wheel-side lever 91 clockwise in the drawing while maintaining these engagements. As a result, the wheel-side lever 91 is
As shown in FIG. 1, the shutter blades 31 and 32 are swung up to a position corresponding to a position where the exposure opening 30 is fully opened at the maximum. When the wheel-side lever 91 swings in this manner, the flywheel 90 is rotated by the wheel-side lever 91 in a direction against the urging force of the torsion spring 92.

In this manner, the motor-side lever 88 is rotated while rotating the flywheel 90 having a large mass and a large inertia against the bias of the torsion spring 92, so that the rotor 86 is fully rotated. The rotation toward the position, that is, the sliding movement of the shutter blades 31 and 32 in the opening direction is performed more slowly than in the case where only the motor 84 is used.

When the rotation direction of the rotor 86 turns to the closed rotation position, the motor-side lever 88 rotates in a direction in which the pressing portion 88a moves away from the receiving portion 91b of the wheel-side lever 91. Further, the flywheel 90 is urged by the torsion spring 92. However, since the inertia is large, the flywheel 90 does not immediately start rotating in the direction urged by the torsion spring 92. The swing of the lever 91 in the direction toward the initial position is not immediately started. Thereby, as shown in FIG. 12, the receiving portion 91b and the pressing portion 88a
With the engagement with the shutter blades 31 released, the shutter blades 31 and 32 are slid by the motor 84 in the closing direction.

As described above, the shutter blades 31, 3
When the slider 2 is slid in the opening direction, by reducing the moving speed thereof, the inertia of the shutter blades 31 and 32 is reduced, so that the responsiveness when the sliding movement is changed from the opening direction to the closing direction is improved. Become. For this reason, for example, the minimum opening diameter corresponding to the upper limit of the range of the controllable exposure value EV can be obtained in correspondence with the shutter blades 31 and 32 having the operation characteristic of which the operation start timing is delayed and the moving speed is slow. Even if the reference position is set, it is possible to reduce the variation in the exposure amount when the operation characteristics are better than this.

When the shutter blades 31 and 32 are slid in the closing direction, the receiving portion 9 is moved as described above.
When the engagement between the pressing portion 1b and the pressing portion 88 is released, the sliding movement of the shutter blades 31 and 32 in the closing direction is started due to the inertia of the flywheel 90 and the urging force of the torsion spring 92. Responsiveness does not deteriorate. The wheel-side lever 91 returns to the initial position with a delay from the start of rotation of the motor-side lever 88 due to the rotation of the flywheel 90 by the urging force of the torsion spring 92.

The urging force of the torsion spring 92 changes according to the rotation angle of the flywheel 90. Therefore, the hole 90b provided in the flywheel 90 and the wheel side lever 9
1 and is assembled so as to match the hole 91d provided on the first torsion spring 9d.
2 is applied to the motor 84 so that the moving speed when the shutter blades 31 and 32 operate in the opening direction is appropriate.

As shown in FIG. 13, the motor 84 is driven by a driver 96 controlled by a drive signal from a drive signal generation circuit 95 of the controller 70. The drive signal generation circuit 95 in this example generates two types of drive signals of “H level” and “L level”,
A drive signal of “H level” is output between the input of the trigger signal from the arithmetic circuit 71 and the input of the stop signal from the timer 72, and when the stop signal is input, “L” is output.
Level ”drive signal for a predetermined time,
After the output of the “L level”, the drive signal is stopped, that is, the output terminal for outputting the drive signal is set to high impedance.

The driver 96 applies a drive current to the coil 87c in a direction of rotating the rotor 86 of the motor 84 toward the fully opened rotation position while the drive signal of the "H level" is being input, and outputs the drive signal "L". While the "level" drive signal is being input, a drive current is supplied to the coil 87c in a direction that rotates the rotor 86 toward the closed rotation position.

The fact that the shutter blades 31 and 32 have reached the reference position indicates that the shutter blades 31 and 32 have reached the reference position.
Is detected by the fact that the projection 50 provided on the shutter has passed the detection position 51a of the photo-interrupter 51, but the response of the shutter blades 31, 32 when turning from the opening direction to the closing direction is improved. By adjusting the length of the protrusion 50 in the sliding direction, for example, when the shutter blades 31 and 32 are slid close to the position where the minimum opening diameter is formed, the protrusion 50 detects the photo-interrupter 51. It passes through the position 51a.

That is, the reference position is the shutter blade 3
In consideration of the operating characteristics of the shutter blades 1 and 32, each of the shutter blades 31 and 32 moving in the opening direction reaches the reference position,
The drive signal is set to “L level” as the generation of the shutter close signal
In this case, at least the opening having the specified minimum opening diameter is adjusted to the position formed by the shutter blades 31 and 32. However, the position is adjusted to the position where the shutter blades 31 and 32 move at a higher speed. , 32 are close to where the minimum aperture diameter forms.

Next, the operation of the above configuration will be briefly described with reference to FIG. FIG. 14 shows a standard characteristic curve of the shutter blades 31 and 32 operating at the design operation start timing and the moving speed by the reference symbol S0, similarly to FIG. 5 shows a worst case characteristic curve within a range of variation in operation characteristics considered when adjusting the position. Also, the symbols D0, D
1 and D2, as in FIG.
A position where c and 32c overlap, a reference position, and a movement position where an opening having a minimum opening diameter is formed are shown.

When the release signal is input, the arithmetic circuit 71 fetches the subject brightness LV from the photometric unit 60, and the exposure value EV is obtained from the subject brightness LV and the film sensitivity of the film unit 20. Then, the exposure value EV is converted into a timer time T. For example, when the exposure value EV is the upper limit value, the exposure value EV is converted into a timer time T of "0" and set in the timer 72. Thereafter, the arithmetic circuit 71 sends the trigger signal to the drive signal generation circuit. Send to 95.

When an “H” level drive signal is output from the drive signal generation circuit 73 in response to the input of the trigger signal, a drive current flows from the driver 96 to the coil 87 c of the motor 84. As a result, the rotor 86 of the motor 84 starts rotating toward the fully opened rotation position.

When the rotation shaft 86a starts rotating together with the rotor 86, the motor-side lever 88 fixed to the rotation shaft 86a presses the receiving portion 91b of the wheel-side lever 91 in a state engaged with the receiving portion 91b, and the wheel-side lever 91 is moved. Rotate while swinging. The wheel-side lever 91 has its sector gear 9
Since 1a meshes with the gear 93, the flywheel 90 having a large mass is rotated against the bias of the torsion spring 92. As a result, the urging force of the torsion spring 92 and the inertia of the flywheel 90 are applied as a load to the rotating shaft 86a of the motor 84, and the rotating speed of the rotating shaft 86a is reduced.

The rotation of the rotating shaft 86a is transmitted to a rotating lever 37 fixed to the rotating shaft 86a.
Starts clockwise rotation at. This rotating lever 3
By the rotation of 7, the shutter blades 31 and 32 slide in the opening direction, respectively. Since the rotation of the rotating shaft 86a is slowed down by the speed adjusting mechanism 85 as described above, the moving speed of the shutter blades 31, 32 is also slowed down accordingly.

The amount of rotation of the rotor 86 increases and the rotation lever 3
As the rotation angle of the shutter blade 7 increases, the amount of sliding movement of the shutter blades 31 and 32 in the opening direction also increases, and when the shutter blades 31 and 32 reach the movement position D0, the openings of the shutter blades 31 and 32 are formed. Parts 31c, 32
When c overlaps and thereafter, when the shutter blades 31 and 32 reach the reference position D1 slightly before the position D2 where the minimum opening diameter is formed, a reference position detection signal is sent from the photo interrupter 51 to the arithmetic circuit 71.

When the reference position detection signal is input, the arithmetic circuit 71 sends a timekeeping start signal to the timer 72 at that moment, and the timer 72 starts timekeeping, but the set timer time T becomes “0”. Therefore, a stop signal is generated at the moment when the timing start signal is input, and is transmitted to the drive signal generation circuit 95. The drive signal generation circuit 95 sets the drive signal to “L level” in response to the input of the stop signal.

When the drive signal goes to "L level", the driver 96 reverses the direction in which the drive current flows, and
Reference numeral 6 reverses the rotation direction. Motor side lever 8
8 when the rotor 86 rotates toward the closed rotation position.
Since the rotation can be performed in a state where the engagement with the first shaft 1b is released, the inertia of the flywheel 90 does not affect the rotation of the rotation shaft 86a. Therefore, after the drive current is turned in the opposite direction, the shutter blades 31, 32
Starts sliding in the closing direction with a delay due to its own inertia, the inertia of the rotating lever 37 and the rotor 86, and the response of the motor 84. And the delay at this time is
Since the moving speed of the shutter blades 31 and 32 in the opening direction is slow, it is smaller than when the moving speed is high.

In this manner, the shutter blades 31, 32
At the moment when the direction of the sliding movement is changed from the opening direction to the closing direction, an opening having a maximum opening diameter of this series of opening and closing operations is formed, after which the shutter blades 31 and 32 slide in the closing direction. By doing so, the exposure aperture 3
0 is completely closed.

The reference position is adjusted so that the maximum opening diameter during a series of opening / closing operations becomes at least the minimum opening diameter in consideration of the variation in the operating characteristics. Therefore, as shown in FIG. When the value EV is the upper limit, the characteristic curve S
In the case of the shutter blades 31 and 32 which become 1, at the same time when the movement position D2 at which the opening having the minimum opening diameter is formed is reached, the sliding movement in the closing direction is started to close the exposure opening 30.

The characteristic curve S0 or the characteristic curve S
In the case of the shutter blades 31 and 32 which are set to 1, the shutter blades 31 and 32 slide in the opening direction after reaching the movement position D2 where the opening having the minimum opening diameter is formed, and thereafter start sliding in the closing direction. , 32, and the rotational speed of the rotor 86 and the rotary lever 37 are low, and their inertia is small, so that the shutter blades 31, 32 have a small delay in switching from the opening direction to the closing direction in the sliding direction. In addition, the amount of movement in the extra opening direction becomes smaller. As a result, even if there is variation in the operating characteristics, variation in the exposure amount is reduced. Of course, even when the exposure value EV corresponding to the subject brightness is smaller than the upper limit value, the variation in the exposure amount is reduced.

In the above embodiment, the opening and closing operation of the shutter blades is performed using a moving magnet type motor. However, the opening and closing operation of the shutter blades may be performed by another type of motor. Further, in each of the above embodiments, the example in which the shutter blade slides has been described.
An opening may be formed by rotating the shutter blade, and the opening diameter may be changed according to the amount of movement (rotation angle). Further, in the above description, the instant camera has been described, but the present invention can be applied to a camera using a roll film of 135 type or the like.

[0077]

As described above, according to the shutter device of the present invention, timing is started when the shutter blade is moved in the opening direction by the driving of the actuator and reaches the reference position. A shutter device that controls the drive of the actuator so that the shutter blade is moved in the closing direction by the shutter closing signal when the time reaches the opening time corresponding to the exposure value. Even if the exposure occurs, an opening having a minimum opening diameter within at least a predetermined range is formed by the shutter blades, so that exposure can be reliably performed even when the subject has high brightness and a high exposure value.

Further, since the rotating shaft of the motor as the actuator is connected to the shutter blade and directly connected to the driving member for opening and closing the shutter blade, the shutter blade is directly driven by the motor, so that it is simple. With this configuration, the shutter blades can be opened and closed. Further, by providing a speed adjusting mechanism and reducing the moving speed of the shutter blade in the opening direction, the responsiveness when the shutter blade moves from the opening direction to the closing direction can be improved, and the variation in the exposure amount can be reduced. can do.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an operation of a shutter device of the present invention.

FIG. 2 is a perspective view showing an instant camera incorporating a shutter device.

FIG. 3 is an explanatory diagram illustrating a schematic configuration of a shutter device.

FIG. 4 is a plan view showing a state where a shutter blade has moved to a reference position.

FIG. 5 is a plan view showing a state at a moment when a shutter blade starts forming an opening;

FIG. 6 is an explanatory diagram showing a state where a shutter blade has a minimum opening.

FIG. 7 is a perspective view showing a shutter blade in an example in which the shutter blade is directly driven using a motor.

8 is a perspective view showing a moving magnet type motor that drives the shutter blades of FIG. 7;

FIG. 9 is an explanatory diagram illustrating a rotation state of a rotor of a motor.

FIG. 10 is an explanatory diagram showing a state of a speed adjusting mechanism when a rotor is at a closed rotation position.

FIG. 11 is an explanatory diagram showing a state of a speed adjusting mechanism when a rotor is at a fully opened rotation position.

FIG. 12 is an explanatory diagram showing a state of a speed adjusting mechanism when the rotor returns from a fully opened rotation position to a closed rotation position.

FIG. 13 is a block diagram illustrating an electrical configuration of the shutter device.

FIG. 14 is an explanatory diagram showing an operation of the shutter device.

FIG. 15 is an explanatory diagram showing an operation of a conventional shutter device.

[Explanation of symbols]

 31, 32 Shutter blade 37 Rotating lever 45 Solenoid 47 Coil spring 50 Projection 51 Photointerrupter 60 Photometer 70 Controller 71 Arithmetic circuit 72 Timer 73, 95 Drive signal generation circuit 84 Motor 85 Speed adjustment mechanism 86a Rotating shaft

Claims (3)

[Claims] 1. A shutter blade which is opened and closed by the driving of an actuator and increases the opening diameter by increasing the amount of movement in the opening direction, and when the shutter blade is moved in the opening direction and reaches a reference position. The shutter blade is moved in the closing direction by generating a shutter closing signal when the time counted reaches the opening time corresponding to the exposure value determined according to the subject luminance. Control means for controlling the driving of the actuator so that the opening time is determined for each exposure value, so that the opening diameter of the opening obtained by opening and closing movement of the shutter blade changes within a predetermined range. In the apparatus, the reference position is such that the shutter closing signal is generated at the same time when the shutter blade reaches the reference position. When it was,
A shutter device wherein the shutter blade is adjusted to a position at which an opening having a minimum opening diameter within the predetermined range can be obtained. 2. The actuator according to claim 1, wherein the actuator is a motor,
2. The shutter device according to claim 1, wherein a rotating shaft of the motor is directly connected to a driving member connected to the shutter blade to open and close the shutter blade, and the shutter blade is directly driven by the motor. . 3. The shutter device according to claim 1, further comprising a speed adjusting mechanism for reducing a moving speed of the shutter blade in the opening direction.