JPS59229533A - Electromagnetically driven shutter - Google Patents

Abstract

PURPOSE:To reduce power consumption by providing a holding means which holds shutter blades at an exposure run end position and a return run end position with the magnetic attractive force of electromagnetic member of an electromagnetic driving source and the mechanical engagement force of an engagement part. CONSTITUTION:At least one of permanent magnets 2a-2d, yokes 1a-1c, and an electromagnetic coil 4 which constitute the electromagnetic member equipped on the fixed or movable side of the electromagnetic driving source which provide driving force to shutter blades 12a-12c and 13a-13c to run is used so as to hold the shutter blades 12a-12c and 13a-13c securely at positions where the shutter blades finish exposure runs and stop and/or at positions where the shutter blades return to run and stop. Then, the holding means 6 utilizes its electromagnetic force to prevent the shutter blades 12a-12c and 13a-13c from running unnecessarily except during shutter releasing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an electromagnetically driven shutter for opening and closing a camera shutter by magnetic drive.

In the past, Isohiroki was often used as the driving source for driving the shutter of a camera. In other words, the shutter drive spring is charged at the same time as the film is advanced, and the force of this spring is used to trigger the shutter in conjunction with the shutter release. ! This type of mechanical shutter is equipped with a member that locks the force of the charged spring before the release operation, and a mechanism that releases this with the release operation.Therefore, such a camera It is very common for the shutter to open accidentally and expose the camera during normal cell phone use, so there was no risk of such an accident unless the shutter button was pressed with some kind of force.

In an electromagnetic drive shutter, an electromagnetic device converts electrical energy into mechanical energy, and this force is used to drive a member of the shutter. Generally, a spring driving force is not required, and the electromagnetic device is energized by operating the shutter release. It was thought that a locking member such as a mechanical shutter would be unnecessary because the driving force was generated to fully operate the shutter blades. However, even if an electromagnetic shutter camera is used, it is still portable.
During storage or during storage, if gravity, finger movement, shock, etc. act on the shutter blade, depending on the configuration of the shutter blade, the shutter may open automatically, resulting in an accident where the frame is exposed to light. Some measures may be required to prevent this. 'E
7. When shooting for a long time with an electromagnetic shutter camera, after rJ has completed the exposure i travel in one direction, turn it back 1
It is desirable to cut off the power to the electromagnetic device during this period to save power, but if the shutter blade is set at this angle, the shutter blades are held only by frictional force, making the above-mentioned accident likely to occur.

The present invention has been made in view of the above points, and is located at the position where the shutter blade completes the exposure travel and stops (at the end of the opening side travel, and at the 1k position where the shutter blade stops after returning). In order to reliably hold the shutter blade at the opening side travel end position), a permanent magnet forming an electromagnetic member provided on the fixed side or the tr1 moving side of the electromagnetic drive source that provides the driving force for traveling to the shutter blade. , a yoke, and an electromagnetic coil, and utilizes the electromagnetic blade to provide a holding means to prevent the shutter blade from inadvertently moving at times other than when the shutter blade is released. It is something to do.

In the present invention, from the jin and VC configured as above,
To achieve this, it is possible to realize a practical electromagnetically driven shutter with an extremely simple configuration without impairing the original purpose of the electromagnetically driven shutter, which omits the mechanical means of the shutter navigation mechanism.

Embodiments of the present invention will be described in detail below with reference to the drawings.

A first embodiment is shown in FIG. 1 and subsequent figures.

FIG. 1 (al is a perspective view showing an embodiment of an electromagnetic drive device according to the present invention, in which one shutter blade of a slit exposure shutter or the like is driven. In the figure, la is a perspective view showing an embodiment of an electromagnetic drive device according to the present invention.

lb and lc are yokes, 2a to 2d are flat permanent magnets such as cloth magnets, and the permanent magnets 2a to 2d are magnetized as shown in the figure and held by the yokes in a sandwich shape as shown in the figure. There is.

5a and 5b are valleys, yokes 1a and lb and lb and lc
Due to the magnetomotive force of the permanent magnets 2a to 2d, magnetic flux is generated in the vertical direction in the magnetic gap 5a and in the vertical upward direction in the magnetic gap 5b.

These electromagnetic members are fixed to the camera base.

Reference numeral 3 denotes a square-shaped coil winding frame bobbin inserted around the yoke lb, and a coil winding frame 4 is wound on the bobbin 3. When the coil 4 starts to be energized, the bobbin receives a force due to the interaction between the energized current and the magnetic flux generated in the gaps 5a and 5bK, and starts to move in the left-right direction. A shutter blade (not shown) is fixed to the bobbin 3.

3a is a protrusion of the bobbin 3, and a triangular prism-shaped high magnetic permeability member 4a is fixed to the protrusion. 11a-1 is a protrusion of the yoke la, and a coil b is wound around the protrusion. 1b-1 is a protruding portion of the yoke 1b, and the protruding magnet 2
Magnetic flux is generated by the magnetomotive forces of a and 2c, and when the bobbin 3 moves to the right, the magnetic permeability member 4a is attracted by the magnetic flux generated in the gap 7, and the first
As shown in Figure (b), the protruding portions 1a-,1,
and 1b-1. The position of bobbin 3 at this time is
The shutter closed state is maintained by the magnetic adsorption force of the high magnetic permeability member 4a and the protrusions 1a-1 and 1b-i of the yoke. .

By the way, the 111th! When the member 4a shown in Q(b) is in contact with the protrusions 1a-1 and 1b-1 of the yoke, the magnetic resistance of the magnetic gap 7 is extremely reduced, so the magnetic flux generated from the permanent magnets 2a and 2c is Most of the yoke protrusion 1
The magnetic flux flowing through a-1 and 1b-1 and generated in the magnetic gap 5a rapidly decreases. However, in the shutter closed state, there is no need for a horizontal force on the bobbin 3 for driving the shutter blades, so the sudden decrease in the magnetic flux in the magnetic gap 5a does not pose a practical problem. At the time of shirt release, for example, in the case of an eye-reflex camera, upon completion of the upward movement of the quick return ball, the coil 6 is energized to generate a magnetomotive force in the same direction as the permanent magnets 2a and 2c, and the permanent magnet 2a and 2cK to cancel the magnetic flux flowing to the protruding portions 1a-1 and 1b-1 of the yoke to zero. In this state, the high magnetic permeability member 4a and the protruding portion 1a of the yoke
The adsorption force with 1 and 1b-1 disappears. Furthermore, by energizing the coil 6, the magnetic flux from the permanent magnets 2a and 2c flows through the gap 5a, causing the gap 5bKIl'
Since the current is originally generated at l&, when the coil 4 is energized, the bobbin 3 easily moves to the left without being restrained by any force, driving the shutter blade.

SWA is a switch for detecting shutter opening, and intercepts 8 and 9
and an insulating member 10. When the shutter is closed, the section 8 is curved by the protrusion 3a of the bobbin as shown in FIG. ), the switch SWA is opened. The purpose of switch SWA is when the shutter is closed,
Due to the shock of 7)), the high magnetic permeability member 4a has a yaw of 1
When it separates from a-1, 1b-1 and starts the shirt opening movement, this is detected by the switch SWA, and the detection signal causes the bobbin 3 to reset in the right direction with respect to the coil 4. The device is designed to turn on electricity and immediately return to the shutter open state. Therefore, by installing the switch SWA, it is possible to prevent the shutter from malfunctioning due to the shutter being depressed or the like when the shutter is opened.

FIG. 2 is a diagram showing an embodiment of the structure of an electromagnetically driven slit exposure shutter according to the present invention, and shows a state at the initial stage of opening of the shutter. In the figure, 11 is the base plate, 12a to 12e are shutter blades, 13a to 13c Fi-ry rear blades, and 14& and 14b are leading blade driving arms, which are rotatable around the left end axis (not shown) ft. be. Further, each of the arms has shutter leading blades 12a to 12c and a shaft 16.
They are rotatably connected by a to 16f. 15a and 15b are arms for driving rear blades, and these arms are rotatable around a shaft (not shown) at the left end. The arms each have a rear shutter blade 13a = 13c and a shaft 17.
They are rotatably connected by a-17f.

20 is an electromagnetic drive device shown in FIG. 1 for driving the shutter leading blade, and 21 is a similar electromagnetic driving device for driving the shutter trailing blade. 3b and 3b' are long grooves provided in the bobbins 3 and 3', respectively, and in the long grooves, the bins 14b-1 and 15a are vertically raised on the leading blade driving arm 14b and the trailing blade driving arm 15a, respectively. -1 is engaged, and due to this engagement, the linear motion force of the bobbins 3 and 3' is transmitted to the leading shutter blade and the trailing blade, respectively. 22 is a shutter opening, and the state shown in FIG. 2 shows the shutter running state.

Electromagnetic drive device (linear motor) used in the above examples
The drive circuit of is shown in FIG. 3(a). This circuit assumes an aperture-priority auto-exposure eye reflex camera with TTL aperture metering.

In the figure, 30 is a photovoltaic water droplet (for example, 5PC) that receives the transmitted light from the photographic lens, and 31 is an operational amplifier (hereinafter abbreviated as OP amplifier) that constitutes the SPC head amplifier, and its both input terminals The 5PC30 is connected to the
A diode 32 for logarithmic compression is connected to the negative feedback path. 33 is a known arithmetic circuit; 33' is a variable resistor for setting information on the number of aperture stages (ΔAv) of the preset aperture;
Reference numeral 4 denotes a variable resistor for setting ASA sensitivity information C8) of the film used, and the output of the arithmetic circuit 33 outputs information (TV) on the number of shutter speeds in seconds to be controlled. 36 is a capacitor for storing the TV information, and 35 is a changeover switch which is normally connected to the a contact and switches to the b contact in conjunction with the start of the upward movement of the quick return mirror. 37 is an OP amplifier constituting a voltage follower, 38 is a transistor for logarithmic expansion, and a time-fixing capacitor 38' is connected to the collector thereof. 39 is a switching transistor for starting counting; 40 is an OP amplifier forming a comparator circuit f; its non-inverting input is connected to the collector terminal of the extension transistor 38; the reference voltage v8 is applied to its inverting input; ing.

49 is a differentiation circuit connected to the output of the comparison circuit 40; 50
is a timer circuit which is triggered by the negative differential pulse of the differential circuit 49 and maintains a high level output for a certain period of time (for example, 20 m5).

52 is a differentiating circuit connected to the output of the timer 50. 45#: t A normally open switch that closes upon completion of the upward movement of the quick return mirror. When this switch is opened, a negative differential pulse is generated from the next stage differential circuit 46.

Reference numeral 47 denotes a timer circuit connected to the output of the differentiating circuit 46, which is triggered by the negative differential pulse of the differentiating circuit 46 and maintains a high level output for a short period of JL1 (for example, 2m5).

46' is an RS flip-flop circuit whose set input is connected to the output of the differentiation circuit 46, and whose Q output terminal is connected to a delay circuit 48.

The output Q' of the delay circuit 48 is connected to the base of the switching transistor 390 for starting counting via a resistor. Reference numeral 53 denotes a timer circuit connected to the output of the differentiating circuit 52, which is triggered by a negative differential pulse from the differentiating circuit 52 and maintains a high level output for one period (for example, 20 m5).

51 is a timer circuit connected to the output of the differentiating circuit 49, which is triggered by a negative differential pulse from the differentiating circuit 49 and maintains a high level for a short period of time (for example, 2 m5).

55 is a two-man powered AND gate, and the 7v1 man-powered one is the RS mentioned above.
It is connected to the flip-flop circuit 46' output,
Other inputs connect the power supply to the positive terminal Vcc of the pond through the shutter open state detection switches 5WA (for leading blades) and SWB L (for rear blades) 2 which are connected in parallel.

41 and 42 are power batteries connected in series, the connection point of which is grounded. MSW is the main switch of the camera, the power terminal on the load side of the switch is named "cc", and both terminals of the battery are named +vcc and -Voc.

Try and Trs are switching transistors for driving the electromagnetic coils 6 and 6', respectively, and their bases are connected to the outputs of the timer circuits 47 and 51 through resistors, respectively. father, its collector each having said coils 6 and 6'.
Also connected are resistors 43 and 44 for current limiting.

54 is a two-man operated OR gate, one input of which is connected to the output T4 of the timer circuit 53, and the other input connected to the output of the AND gate 55. 56 is an inverting circuit connected to the output of the OR gate 54.

Driving transistors Tr1 to Tr of the electromagnetic coil 4.4'
6 has a bridge configuration as shown in the figure. 4 is a coil for driving the shutter leading blade shown in FIG. 2, 4' is a coil for driving the rear blade, and the coil 4d is a switching transistor Trl.
(Tr,) (/, J: ffvkuta and Trs (Tr
4) is connected between the collectors. Father, coil 4'
is the collector of the switching transistor Tr H ('rr t) and the switching transistor Trs (Tra)
connected between the collectors. In the figure, the direction of arrow A is the direction in which current flows when the shutter is running, and the direction of arrow B is the direction in which current flows when the shutter is reset. The base of the switching transistor 1r is the four outputs of the RS flip-flop circuit 46, and the base of the transistor Tr is the output of the OR gate 54.

and the base of Tr5 is connected to the output of the inverting circuit 56 and 'I
'r, the base of the RS flip-flop circuit 4
The four outputs of 6 and the base of Tra are the timer circuit 50.
It is connected to the outputs T3 and '4 of the circuit through a resistor.

Reference numerals 57 to 60 represent constant current circuits, which are connected to the collector terminals of the switching transistors Trl to Tre, respectively, and are configured to flow a constant current in the forward and reverse directions of the leading blade coil 4 and the trailing blade coil 4'. . Also, constant current circuit 5
The output streams 8 and 60 are set to be equal so that the running speeds of the leading blade and trailing blade during shutter travel are the same.

The operation of this circuit configured as described above will be explained based on the time chart of FIG. 3(b).

A voltage is generated in the output of the SPC head amplifier 30 according to the subject brightness By and the open F value AVO of the photographing lens,
The output voltage is calculated in the next stage calculation circuit 33 using the aperture stage number information ΔAv of the preset aperture and the ASA sensitivity information Sv of the film used, and a voltage corresponding to the shutter speed information TV to be controlled is generated at its output. The voltage is stored and held in a storage capacitor 36.

Next, when the shirt release operation is performed, the quick return spring starts to move upward by means not shown, and the changeover switch 35 is connected to the b contact. Therefore, the storage voltage of the storage capacitor 36 is outputted from the OP amplifier 37. When the upward movement of the quick return baller is completed, the switch 45 is closed and the differentiating circuit 46 is closed.
A negative differential pulse is generated from the output of T, and this pulse triggers the timer circuit 47, whose output remains at the u level for a short period of time, during which time the switching transistor T
r7 is turned on, and the coil 6 shown in the second diagram is energized during that time. Therefore, as described in FIG. 1, the adsorption force of the member 4 disappears. The negative differential pulse from the differential circuit 46 causes the RSS flip-flop circuit 46' to set its Q output to H level and invert its 4 output to L level.

Therefore, the switching transistors Tr1 and Tr are turned on, and a current defined by the constant current circuit 58 flows in the direction of arrow A in the coil 4 of the leading blade, and the bobbin 3 in FIG. 1 starts moving to the left. , the shutter leading blade starts running.

Furthermore, a little later than the H level inversion of the output Q of the flip-flow knob circuit 46', the delay circuit 48 (the purpose of which is
This is to compensate for the delay from the start of the shutter leading blade travel to the start of exposure. ) output Q'tj: becomes H level,
The switching transistor 39 for starting the count is turned off. Therefore, the time setting capacitor 38' is
It is charged by the logarithmically expanded current of the output voltage of the P amplifier 37, and its terminal level voltage JC is as shown in Fig. 3(b).
It descends as shown in the figure. When this voltage JC becomes less than the inverted input voltage v8 of the OP amplifier 40 that constitutes the comparator circuit, the output OP of the OP amplifier 40 is inverted to L level, and a negative differential pulse is generated from the next stage differentiating circuit 49. , the next-stage timer 51 is triggered by this pulse, and its output T is held at the H level' for a short period of time (for example, for 2 mS). When the output T of this timer 51 becomes H level, the switching transistor Tra turns on.
The coil 6' shown in the second diagram is energized. Therefore, as described above, the suction holding force of the bobbin 4' disappears. Further, the timer 50 is also triggered by the negative differential pulse from the differentiating circuit 49, and its output T is output for a certain period of time (for example, 20 m
5) H level is maintained. When the output T3 of this timer 50 becomes H level, the switching transistor Tr6 is turned on, and the switching transistor T
Since r is turned on as described above, a current defined by the constant current circuit 60 begins to flow in the direction of arrow A in the coil 4' of the rear shutter blade, and the bobbin 4 as described above begins to flow.
Since the suction holding force of ' has disappeared, the rear shutter blade begins to run. The time during which the output T3 of the timer 50 is held at the H level is set to be slightly longer than the time required for the trailing shutter blade to complete its travel, in order to ensure that the trailing shutter blade completes its travel.

When the output T of the timer 50 returns to the L level, a negative differential pulse is generated from the next-stage differentiating circuit 52, and the RS flip-flop circuit 46' is reset by this pulse, and its Q output and output are Inverted to L level and H level, respectively. Moreover, the output TarjL of the timer 50,
level, so the switching transistor Tr1,
Tr4 and Tr, H are turned off.

Further, the timer circuit 53 in the next stage is triggered by the negative differential current of the differentiating circuits 52, and its output T4.
maintains the H level for a certain period of time (for example, for 20 m8).

During this time, the output of the next-stage OR gate 54 is held at H level, and the output of the inversion circuit 56 is held at L level. Therefore, in the meantime,
Switching transistor Tr* + Trs and Tr
5 is turned on, and a constant current defined by constant current circuits 57 and 59 flows in the direction of arrow B in the leading blade coil 4 and trailing blade coil 4', respectively, and the leading blade and trailing blade start the reset movement tl-. do. Output T4 of the timer circuit 53
The time for which the blades are held at the H level is set to be slightly longer than the time for the leading and trailing blades to complete resetting, in order to ensure that the reset is completed.

As explained above, this circuit energizes the coils 6 and 6' for a short period of time when the shutter blades of the coil 4 for driving the leading shutter blade and the coil 4' for driving the trailing blade are started for a short period of time. The suction and holding force of the bobbin is eliminated, and during that time, the coil 4 or 4' on the bobbin side is energized to facilitate the movement of the bobbin. Further, in this circuit, the coil 4 is energized even after the shutter leading blade travels until the start of the reset operation to prevent the shutter leading blade from returning due to a shock or the like.

Next, the opening prevention operation when the shutter is closed will be explained.

First, to explain the opening prevention operation of the shutter leading blade, in the Jt diagram (b), the engagement between the protrusions 1a-1 and 1b-1 of the yoke and the cylindrical magnetically permeable member 4 is disengaged due to some kind of shock. Then, if the bobbin 3 moves to the left, the protrusion 3a of the bobbin 3 and the cut 8 of the switch SWA become disconnected, and the switch SWA closes as shown in FIG. 1(a). do.

Therefore, the AND gate 55 &) 1 manual power level in FIG. The output of gate 55 becomes H level, the output rIill level of OR gate 54 and the output of inverting circuit 56 become L level. Therefore, the switching transistors 'lrt I Try and l1lrs are turned on, current flows in the reset direction (B direction) through the shutter leading blade coil 4 and the rear blade coil 4', and the bobbin 3 receives the force in the right direction and moves in the right direction. Then, the protruding portion 1a-1 of the yoke
and 1b-1 are again attracted to the highly permeable member 4 to maintain the shutter closed state.

In the case of the shutter trailing blade, the switch SWB operates in the same manner. Incidentally, while the shutter leading blade and trailing blade are running, the switches SWA and SWB are closed, but at this time there is no need to flow current in the opposite direction to the coils 4 and 4'. Therefore, while the shutter is running, the RSS
The Q output of the flip-flop circuit 46' is at L level, and the output of the C1AND gate 55 is connected to the switch SWA.
and 11 to L level regardless of the open/closed state of SWB,
Therefore, the coils 4 and 4' are not energized in the opposite direction while the shutter is running.

Next, 4th v to 718th! ! A second embodiment of the invention will be described by J. The first (1) embodiment described above has a structure in which the electromagnetic member is brought into contact with the shutter blade and the position of the shutter blade is held by the attraction force generated by the electromagnetic force, but in the second embodiment described in detail below, , which engages the lock pawl using electromagnetic attraction force to achieve more reliable locking.

4(a) is a perspective view of the drive unit, FIG. 4(b) is a side view of the same, FIG. 4(c) is a rear view of the same, and FIG. 4(d) is a perspective view of the drive unit.
It is a top view of the slit exposure shutter provided with the drive part of a)-(C). In the figure, the same parts as in FIG. 1 are marked with the same reference numerals. As shown in FIG. 4 (at), in this embodiment, the leading blade driving coil 4 and the trailing blade driving coil 4' are arranged with the same yoke xbfci; 1 m apart, and the bobbin 3.3' is It is connected to the operating arms of the shutter leading blade and trailing blade by pin-groove engagement in the same manner as the S connection in Fig. 2. D is made of a magnetically permeable material fixed to the bobbin 3 of the leading blade driving coil. The retaining member 6C is a holding locking claw rotatably supported by the yoke IC, and the locking claw C and the protrusion 100 of the yoke lb are connected to each other.
0, yokes la, lb, and permanent magnet 2a constitute a magnetic circuit, and in the state before the shutter is exposed, the retaining member member and the hook of the lock claw C engage with each other and are magnetically attracted to each other. Since the shutter blades are held in place, the shutter blades will not open inadvertently due to a slight impact.

In this case, the bobbin 3' of the trailing blade driving coil is held together with the leading blade bobbin 3 by a lock claw C.

When the release operation is performed from this state, the degaussing coil F wound around the protrusion 1000 of the yoke is energized by the circuit shown in line 9 and FIG. C is rotated counterclockwise in the figure by the force of spring E, and the engagement with the engagement member is released.

Next, the drive coils 4 and 4' are sequentially energized to move the coil bobbins 3 and 3' to the right in the figure, and the shutter leading and trailing blades travel for exposure. When a current in the opposite direction is supplied to the drive coil 4.4' in the same way as in the previous embodiment, the bobbin 3.3' moves to the left in the figure, causing the shutter blade to travel #. At the end of this return run, when the tip of the engagement member approaches the lock claw CVc and enters between the tip of the lock claw C and the protrusion 1000 of the yoke, the magnetic attraction force increases and the lock claw C becomes a spring. The shutter blade rotates clockwise against E, and the hook portion mechanically engages again and magnetically attracts the shutter blade to hold the shutter blade at the return travel completion position.

In addition, if it is necessary to temporarily hold the shutter blade at the photon position during exposure travel, provide a locking claw similar to the upper B/C at the photon position, and attach a locking claw similar to D to the rear blade bobbin 3'. It's good to have the parts.

Also, is there a means to hold the running light of the tip blade for long exposure? It is also possible to set one.

Next, FIG. 5 shows an example in which the spring Ei of the lock pawl C in the embodiment shown in FIG. It is designed to absorb. The lock claw C is excited to the north pole by the yoke 1a, and is held by attracting the south pole of the pole piece H. When the tip of the drive coil member approaches the tip of the pawl C, an attractive force is generated between the two ends, and the lock pawl C rotates against the attraction force due to the magnetic force at the other end, so that the lock pawl C rotates in the direction IDt-long. The other operations are the same as those in the embodiment shown in FIG. 4, so their explanation will be omitted.

Fig. 6 shows the device shown in Fig. 5 provided with a bounce prevention mechanism during locking, in which the protrusion C' of the lock pawl C and the tip protrusion D' of the coil drive member engage when locking, causing the pawl C to clockwise. It is designed to lock automatically when pushed in the direction.
This prevents the device from bouncing when locked in the embodiments of FIGS. 4 and 5.

Next, FIGS. 7 and 8 are perspective views showing the structure of an electromagnetic drive device in a third embodiment of the present invention. In this embodiment, the coil for removing the lock (provided on the side of the lock claw C) is omitted, and instead, a coil is provided in the lock claw portion of the drive coil 1111 to perform the braking and release operations during locking. In the apparatus shown in FIG. 7, a coil (2) is provided on the member, and when the member is energized to move to the left in the figure, the coil (2) is energized to the north pole at the tip. Since the tip of the locking pawl C disposed on the fixed yoke is an S pole, when the tip of the member approaches, an attractive force is generated between the magnetic poles of both of these pawls, and the lock is established. At this time, the brake is applied by the oblique part of the claw. Note that a non-magnetic member J is arranged at the other end of the claw C to restrict the rotation range.

Next, at the time of resetting, an excitation current is passed in the opposite direction to the coil (2), and by exciting the S pole of the tip thereof, it automatically repels the S pole of the lock pawl C, and the lock is released.

The device shown in Fig. 8 has a structure in which the coil ■ in Fig. 7 is not provided separately and is used also as the blade drive coil 4.4'C.
In this case as well, it is possible to carry out the same operation as shown in FIG. In addition, in Fig. 8, there is a protrusion K on the stator yoke.
G and L? r is arranged to make the locking operation more reliable.

In the above embodiment, the coil l can be wound by winding a part of the blade driving coil 10'', and the winding t to this can be done in series in the same circuit as the driving coil. Therefore, as shown in FIG. The circuit used in the embodiment of FIG. 8 may be the same as the circuit of the first embodiment (FIG. 3) from which the degaussing coils 6 and 6' are removed.

As mentioned above, in the electromagnetically driven slit exposure shutter of the present invention, the shutter driving η is also applied to the magnetic device by the attractive force of the permanent magnet that drives the electromagnetic drive source or by the mechanical force generated by this, in order to avoid unnecessary power consumption as much as possible. The shutter blade is held at the end of travel position using the force of holding the shutter blade. In this case as well, wasteful power consumption is minimized and the shutter blades can be held stably, so it will be very effective in the configuration of a slit exposure shutter that uses an electromagnetic drive source. It is something.

Although each of the above-mentioned embodiments concerns a slit exposure shutter, the IIA excitation method according to the configuration of the present invention is not only applied to a slit exposure shutter, but it can also be modified for a lens shutter. It can be overused and has low power consumption.
It is possible to construct an electric 4B drive shutter with excellent performance that performs stable operation.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the electromagnetic drive device according to the present invention. FIG. 1(a) shows the state before the shutter blade holding means enters the holding state, FIG. It is a diagram showing a state in which the holding means holds the shutter blade. Second
The figure is a plan view showing an embodiment of the fW magnetically driven slide exposure shutter according to the present invention, and FIG. 3(b) is a typing chart showing the operation of each part of the circuit of FIG. 3(a), and FIG. 4(a) is a perspective view showing a third embodiment of the electromagnetic drive device of the present invention. ,
4(b) and (C) are plan views and side views of essential parts showing the shutter blade holding state of the device in FIG. 4(a), and FIGS. 5 and 6. 4 is a plan view of essential parts showing another embodiment of the electromagnetic drive device of the present invention, FIG. 7 is a perspective view showing a third embodiment of the electromagnetic drive device of the present invention, and FIG. FIG. 3 is a perspective view showing another configuration of the third embodiment. la, lb, lc...Yoke, 2a, 2b, 2c, 2d...Permanent magnet, 3.
...Mover coil bobbin, 3a...Bobbin protrusion, 4...Mover coil, 1
a-1, 1b-1...Yoke magnetic shunt protrusion, 5
B, = 45 b...Magnetic gap, 6...Degaussing coil of holding means, 7...Magnetic gap of magnetic shunt, 8.910...Touch piece constituting switch SWA, C;
Lock claw, D: Engaging member, E: Spring, F: Demagnetizing coil. Patent Applicant: Canon Co., Ltd. Wa IGI'

Claims (1)

[Scope of Claims] (1) An electromagnetic drive source that causes the shutter blade to travel for exposure and return, and an engagement member disposed between a stator and a movable element of the electromagnetic drive source. , characterized by comprising a holding means for holding one blade of the 7-shaped blade at the exposure travel end position and the return travel end position by the magnetic attraction force of the electromagnetic member of the electromagnetic drive source and the mechanical retention force of the retention member. Electromagnetic drive Nyanotar. (2) The electromagnetic drive source is constituted by a single stator, a leading blade driving movable element and a trailing blade driving movable element arranged before and behind the magnetic field of the stator, and the holding means is Claim 1 is characterized in that the holding means is provided between the blade driving movable element and the rear blade driving movable element, and the rear blade is held at the return travel end position together with the leading blade by the holding means.
Electromagnetic drive shutter described in ). (Katana) The stator of the electromagnetic drive source is provided with a locking claw that engages and disengages with the hook member of the movable element, and one end of the locking claw is made to hold the absorption layer using the attractive force of the magnetic shunt provided in the stator. The electromagnetically driven shutter according to item (1) or item (2) of the scope of the RF requirements. Claim (3), characterized in that the protrusion is pressed by the tip of the member to engage the lock pawl and the hook member.
(5) The holding means is rotatably supported by one pole of a fixed rectangular yoke of the electromagnetic drive source, and between a magnetic shunt arranged at the other pole of the yoke. It consists of a lock pawl that forms a magnetic path and a movable element V (a fixed hook member with high magnetic permeability), and an electromagnetic wire ring is provided in the stator magnetic branch, and energization to the ?# ring, VC Therefore, the characteristic Flf m# required range (1
) or (2). (6) The holding means is composed of a lock claw disposed on the stator of the electromagnetic drive source, and a flick member with a quotient magnetic permeability disposed on the slider and engaged with the lock claw at the travel end position.
L. The drive line wheel of the electromagnetic drive source or a part of the drive line wheel is wound around the hook member, and the hook member is fully excited by passing through the drive line 11. The electromagnetically driven shutter according to range (3).