JPS6324231A - Electric exposing device - Google Patents

Abstract

PURPOSE:To remove a dead space by forming a projection part with projection length shorter than that of a motor on the end face of an exposing device body. CONSTITUTION:A motor 19B for driving a diaphragm blade 16 extrudes on one end face of the exposing device body 19A and a partially circular projection part 19C is fitted to the end face on which no motor 19B exists. The relation between the axial direction length l1 of the motor 19B and the axial direction length l2 of the projection part 19C is l1>=l2, so that the end face of the whole electric exposing device including the motor 19B and the projection part 19C is almost flat. In case of loading the exposing device into a zoom lens barrel, a space R having no motor 19B does not become a dead space at the stroke end of zooming operation.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an exposure device such as a shutter or an aperture device for equipping a camera and its interchangeable lenses, and more particularly, to The present invention also relates to a light and compact electric exposure apparatus that has a large diameter, has excellent control responsiveness and high-speed operation, and is lightweight and compact.

[Background of the invention]

The non-interchangeable lens type 35-kaku camera is generally called a compact camera, and this type of camera is equipped with a lens shutter device that serves as an exposure device and a shutter and an aperture. The lens shutter device installed in recent compact cameras has a direct electromagnetic drive structure.In such a direct electromagnetic drive structure, the lens shutter device carries shutter blades (i.e. aperture blades). The sector ring itself has awakened! It is the rotor of the drive device (i.e. motor). In addition, Nagomi has proposed a lens shutter device in which the sector ring is rotated by a cylindrical (or ring-shaped) stepping motor that has a ring-shaped rotor with the same diameter as the lens barrel. has been done. (For example, see Japanese Patent Application Laid-open No. 17428/1983).

These known lens shutter devices have nine aperture blades (
Since the sector ring carrying the sector is driven by a motor directly coupled to it, no complicated mechanical mechanism is required to rotate and position the sector ring by any desired angle; It is small and lightweight, and is suitable for electronic control.

On the other hand, single-lens reflex cameras (hereinafter abbreviated as single-lens reflex cameras) are equipped with larger-diameter lenses than compact cameras and can be replaced with interchangeable lenses. The lens X") is equipped with an aperture device, and the aperture device is mechanically driven from an aperture reverse drive device provided inside the camera body via an interlocking lever. In the conventional single-lens camera 7 with such a structure, the mechanical structure of the aperture drive device inside the camera body is not complicated, and the mechanical structure of the aperture drive device, including the interlocking lever, is not complicated. Because the mechanical structure inside the lens barrel is complicated, the weight of the entire camera including the lens barrel is heavy and the volume of the entire camera is large.Also, the power transmission to the aperture device is difficult. Since this is done via a complicated mechanical power transmission mechanism, the responsiveness of the control operation is poor, and electronic control traps are unsuitable.

Therefore, in conventional single-lens reflex cameras, it has been necessary to reduce the overall weight of the camera by improving the aperture force device, and to realize an aperture device that operates at high speed and has good control response.

In order to realize an aperture device that can reduce the size and volume of the camera body and interchangeable lenses, operates at high speed, and has good control response, K is designed to realize an aperture device that operates at high speed and has good control response. , preferably configured as a direct electric strangulation device.

However, in the electromagnetic driving device of the lens shutter conventionally equipped with compact cameras, the sector ring itself (or a rotary plate of the same size as the sector ring) carrying the blades is rotated by the rotor. In addition, in the lens shutter device disclosed in the above publication, since the rotor is a large-diameter ring, the inertia of the rotor itself is extremely large (as is well-known, the diameter of one rotating body is D). If the gravitational acceleration is G, the inertial mass of the rotating body is proportional to GD K. Therefore, in the electromagnetic drive device described above whose rotor is a large annular body with a large D, the inertia of the rotor is 5!1.i3 is very large), Therefore, starting performance and control response are poor1, and since the stator coil is a circular coil wound around the optical axis, the number of turns cannot be increased, so high ampere turns cannot be obtained. Therefore, there are drawbacks such as only a small starting torque can be obtained. Therefore, although it is practical as an aperture drive motor for small-diameter lenses such as compact cameras, it is impossible to use the structure of this electromagnetic drive device as a motor for large-diameter aperture devices for single-lens reflex cameras. Met. In other words, if a motor for a large-diameter diaphragm device with the same structure as the electromagnetic drive device is designed, it is difficult to start the rotor because the magnetomotive force cannot be increased even though the inertial mass of the rotor is extremely large. As a result, step-out easily occurs, and the rotor often remains vibrated at the stop position and does not rotate.

Therefore, it has been found that an electric aperture device for a large-diameter lens cannot be realized with an aperture device having the same structure as a lens shutter device equipped in a conventional lens shutter device or camera.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electric exposure device that is applicable to cameras and lenses with a larger diameter than compact cameras.

[Summary of the Invention] An electric exposure apparatus according to the present invention includes an exposure apparatus main body that incorporates parts necessary for exposure such as light-shielding blades (aperture blades), and a motor that protrudes from one end surface of the exposure apparatus main body. ,
and a protrusion provided on the end face at a position where the motor is not present, with a protrusion length shorter than the protrusion length of the motor, and for example, a control electronic circuit or the like is accommodated in the protrusion. There is.

In the electric exposure device of the present invention, since the end face is almost flat due to the provision of the limb protrusion, even when the electric exposure device is installed in a lens barrel with a zoom mechanism, the stroke end position of the zoom operation can be adjusted. In this case, there is a dead gas inside the lens barrel.
The space within the lens barrel is efficiently utilized, and the size of the camera and interchangeable lenses can be made smaller. Furthermore, since the electric exposure device of the present invention generates a larger torque than conventional devices for compact cameras, it is possible to motorize the aperture device of large-diameter cameras such as single-lens reflex cameras, and as a result, - It is possible to make large-diameter cameras such as eye reflex cameras lighter, smaller, and electronically controllable.

[Embodiments of the invention]

FIG. 1 is a partially exploded perspective view of an electric exposure apparatus 19 of the present invention. In FIG. 1, reference numeral 19A is an annular disk-shaped exposure device main body that incorporates aperture blades (shading blades) 16 and related parts, and one end surface of the exposure device main body 19A has the aperture blades 16 for driving. A motor 19B is provided protrudingly for this purpose, and a partially annular protrusion 19C as shown is attached to the end face at a position where the motor 19B is not present. The axial length tl of the motor 19B and the axial length tl of the protrusion 19C satisfy t1≧1. Therefore, the end surface of the entire electric exposure device including the motor 19B and the protrusion 19C becomes almost flat, so that when the electric exposure device is installed in the zoom lens barrel, the end surface of the entire electric exposure device becomes almost flat. There is no possibility that the space R where the motor 19B does not exist becomes a dead space at the stroke end of the operation.

That is, when the electric exposure device of the present invention is incorporated into a zoom lens barrel, the space within the barrel can be effectively utilized, and as a result, the size of the interchangeable lens or the like can be reduced.

Note that if, for example, an electronic circuit or the like is accommodated in the protrusion 19C, the utility of the protrusion will be increased. In addition,
It is desirable that the protrusion 19C be removably attached to the end surface of the exposure apparatus main body 19A.

Next, the detailed structure of the electric exposure device 19 will be explained with reference to FIG. 2 and subsequent figures.

The electric exposure apparatus of this embodiment shown in an exploded state in FIG. 2 comprises a motor 19B (in this embodiment, a two-phase stepping motor) that drives the light-shielding blades, that is, the aperture blades, which will be described later. a rotor 2 and stators 6 to 9 and coils 12 and 13 for excitation of the stator; a first support member l in the form of an annular disk supporting one end side of the rotor, stator, and coil; fastened to the support member 1; a cam plate 15 (i.e., a second support member); a rotating ring 17 rotatably supported by the cam plate 15 and rotated by the rotor 2; 9 diaphragm blades 1 whose movement is controlled
6. A conductive turn plate 14 which is fastened to one end of the support member 1, and a flexible conductor which is electrically connected to the conductive turn plate 14 and electrically connected to the coils 12 and 13. It is composed of a printed board 18, a bearing plate 5 that supports the other ends of the rotor 2, stators 6-9, and coils 12 and 13.

The exposure apparatus main body 19A is composed of a support member 1, a cam plate 15, a rotating ring 17, an aperture blade 16, etc., and is equipped with a detection means for the rotating ring 17, which will be described later.

The support member 1, the cam plate 15, and the rotating ring 17 each have optical path holes 1a, 151, and 17g, each having an inner diameter corresponding to the diameter of the photographing lens. The support member 1 has a bearing 1b that rotatably supports one end 2a of the shaft of the rotor 2 at a position outside the optical path hole 1&.
includes a hole 1d into which the iron core 10 of the coil 12 is fitted and fixed, a hole IC into which the iron core 11 of the coil 13 is fitted and fixed, and a cam plate 15.
A screw hole 1e for screwing in a screw 3 for fastening the conductor pattern plate 14 to the support member 1, and a long hole If for changing the fastening position of the conductor pattern plate 14 with respect to the support member 1 are provided.

On the other hand, an arcuate bearing plate 5 disposed opposite to one end surface of the support member 1 at a predetermined interval has a bearing 5a rotatably supporting the other end 2b of the shaft of the rotor 2, as well as a coil 12. A hole 5b into which the iron core 10 of the coil 13 is fitted and fixed, and a hole 5C into which the iron core 11 of the coil 13 is fitted and fixed are provided. is arranged in a space outside the optical path hole 11 of the support member 1 (in other words, a space outside the virtual cylinder whose cross section is the optical path hole 17m of the rotating ring 17), and at the periphery of the optical path hole 1a. are arranged in an arc along the And only rotor 2 has bearing 1
b and 5 are supported so that they can only rotate, and the other members (i.e., stators 6 to 9 and cores 10 and 11 of coils 12 and 13, respectively) are supported by support member 1 so that they cannot rotate or move in the axial direction. It is supported by a bearing plate 5 and a trap.

The stators 6 to 9 have a plurality of teeth 6a to 9a arranged in an arc shape along the outer peripheral surface of the rotor 2, and have iron cores 10 and 1.
It has holes 6b to 9b into which 1 is fitted and fixed. The stators 6 and 7 are fitted into the core 10 of the coil 12 in their respective holes 6b and 7b, and are supported in a stationary state together with the core 10 by the support member 1 and the bearing plate 5. It is fitted into the iron core 11 of the coil 13 in the holes 8b and 9b, and is supported in a stationary state by the support member 1 and the bearing plate 5 together with the iron core 11.

The rotor 2 is a cylindrical body made of permanent magnets, and on its outer peripheral surface, north pole pieces and south pole pieces parallel to the axial direction are arranged alternately in the circumferential direction, and each north pole piece and each south pole piece are arranged in the circumferential direction. The circumferential length of the pole piece is approximately equal to the circumferential length of the teeth 6a-9a of the stators 6-9. In this embodiment, the N of the outer peripheral surface of the rotor 2 is
The numbers of poles and south poles are 11, respectively. That is, the outer peripheral surface of the rotor 2 is composed of 11 north pole pieces and 11 south pole pieces arranged alternately.

The teeth 6a of the stator 6 and the teeth 71' of the stator 7 are arranged alternately along the outer peripheral surface of the rotor 2, as shown in FIG.
Similarly, the teeth 9& are alternately arranged along the outer peripheral surface of the rotor 2.

The width 2 of the inner end surface of each stator tooth (the circumferential length t on the surface facing the outer circumferential surface of the rotor 2) is approximately equal to the circumferential length of each pole piece of the rotor 2 facing it, and therefore the stator tooth and the magnetic pole pieces of the rotor 2 are arranged to directly face each other.

However, in this embodiment, as shown in FIG. The teeth 8a and 9a are arranged at an intermediate position between the north pole piece and the south pole piece of the rotor 2.

The shaft 2& at one end of the rotor 2 passes through a bearing 1b provided on the support member IK and projects to the other end of the support member 1, and a pinion 4 is attached to the projecting portion. Teeth 1 on the outer circumferential surface of the rotating ring 17, which will be explained after the fourth pinion.
7c, and transmits the rotation of the rotor 2 to the rotating ring 17.

A power supply line 12 to the coil 12 is connected to the lower part of the left end surface of the support member 1 (the end surface on the side where the rotor 2 etc. are arranged).
A flexible printed board 18 to which a power supply line 13a to the coil 13 and a supply line 14b to the conductive nine-turn plate 14 are connected is attached with screws or adhesive. On the other hand, on the right end surface of the support member 1, a conductive middle turn plate 14 having a conductive pattern 14& is attached to the screw 14.
The screw 14c is inserted into a circumferential elongated hole 1f extending through the support member IK so that the fastening position of the conductive pattern plate 14 can be changed. The conductive pattern board 14Vi is electrically connected to a flexible printed board 18 via a power supply line 14b, and is connected to a control circuit via the flexible printed board 18.

The cam plate 15 fastened to the support member 1 has four flat protrusions 15b to 15b corresponding to the positions of the screw holes 1e of the support member 1.
15e, and an oval hole 15f into which the screw 3 can be inserted is provided through the protrusions 15b to 15s.

The hole 15f is elongated in the circumferential direction. Therefore, when the screw 3 is inserted into the hole 15f, the screw hole 1e of the support member 1 is inserted.
When fixing the cam plate 15 to the support member 1 by screwing into the
By slightly rotating the cam plate 15 in the circumferential direction, the fastening position of the cam plate 15 to the support member 1 can be changed.

The protrusions 15b to 15e of the cam plate 15 are configured as spacers for forming a gap between the support member 1 and the cam plate 15, and the inner circumferential surfaces of the protrusions 15b to 15 are used to support the rotating ring 17. It is configured as a surface, and the rotating ring 1
The outer circumferential surface of 7 is rotatably supported by the inner circumferential surfaces of the protrusions 15b to 15a.

Five pin holes 17 are formed in the rotating ring 17, and each of the pin holes 17m has a diaphragm blade 16 (only one is shown in FIG. A protruding pin 16b is inserted rotatably (not axially movable). That is, five diaphragm blades 16 are pivotally attached to the rotating ring 17. Each aperture blade 1
6 is controlled by a cam groove 15m formed on the cam plate 15, and a pin 16 protruding from each blade 16 is inserted into the cam groove 15& so as to be relatively slidable. .

The outer peripheral surface of the rotating ring 17 is provided with teeth 17a, which are driven gear parts for deceleration that mesh with the pinion 4, and a protrusion 17b.

The conductive pattern 1 on the conductive pattern plate 14 is attached to the protrusion 17b.
A contact piece 17d that makes sliding contact with the diaphragm 4m is attached, and the conductive pattern 14m and the contact piece 17d constitute an on-off type detection means for electrically detecting whether the aperture is in an open state or a small aperture state. . In the case of this embodiment, when the contact piece 17d is in contact with the conductive pattern 14a, the diaphragm is in a small diaphragm state, and when the contact piece 17d and the conductive pattern 14m are not in contact, the diaphragm is in an open state. It is configured as follows. The detection means is for determining whether the aperture is open or not. For example, when the aperture blades move toward the small aperture due to an external impact, photometry is prohibited (i.e., , photography is prohibited).

When the supporting member 1, the cam plate 15, and the rotating ring 17 are assembled, the protrusion 15b of the cam plate 15 is attached to the rotating ring 17.
It is positioned between the protrusion 17b and the tooth 17e. Therefore, when the single rotation ring 17 is rotated clockwise in FIG. 1, the clockwise rotation of the rotation ring 17 is prevented when one end 17f of the tooth 17e comes into contact with one end surface 15g of the protrusion 15b. When the rotating ring 17 is rotated counterclockwise, one end surface 17 of the protrusion 17b comes into contact with the other end surface 15h of the protrusion 15b, and the rotating ring 1
7 is prevented from rotating counterclockwise. That is, the protrusion 15b of the cam plate 15, the protrusion 17b of the rotary ring 17, and one end 17f of the tooth 17e are configured as a stopper for restricting the rotation of the rotary ring 17 within a certain rotation angle range.

FIG. 3 is a diagram for explaining the relative positional relationship between the rotor 2 and the stators 6 to 9 and the rotation indexing operation of the rotor 2.

Further, FIG. 4 is a chart corresponding to FIG. 3 for explaining the excitation states of the stators 6 to 9.

FIG. 3(a) shows the relative positional relationship between the rotor 2 and the stators 6 to 9 when the coils 12 and 13 are not energized. The rotor 2 is stationary with the north pole piece of the rotor 2 facing each tooth 7a of the stator 7. On the other hand, at this time, each of the teeth 81 and 9a of the stator 8 and the stator 9 is directly opposed to each half of the S pole piece and half of the N pole piece of the rotor 2. In this case, the angle θ between the endmost tooth of the stator 7 and the tooth of the stator 8 closest to the tooth is expressed as θ=nP+1P. (However, P is the pitch of adjacent teeth of stators 6 and 7,
It is also the pitch of adjacent teeth of the stators 8 and 9.

) In order to rotate the rotor 2, which is stopped in the state shown in FIG.
The energization time (or number of control pulses) and energization direction for 3 are controlled as shown in FIG. 4, for example.

FIG. 4 shows the energization direction and energization time for the coils 12 and 13, where the horizontal axis shows the energization time (or number of pulses) and the vertical axis shows the on/off state. Also,
As shown in FIGS. 3(b) to 3(d), A indicates energization in the positive direction to the coil 13, B indicates energization in the reverse direction to the coil 13, B indicates energization in the positive direction to Coil/L/12, and B 1 and 2 respectively represent energization in the opposite direction to the coil 12.

A method for controlling the rotation of the rotor 2 will be described below with reference to FIGS. 3(b) to 3(d) and FIG. 4.

As shown in FIGS. 3(b) and 4, when the coil 13 is energized A and the coil 12 is energized B, the teeth 6a of the stator 6
is N, tooth 7a of stator 7 is S, tooth 8 of stator 8 is
a is magnetized to N, and the teeth 9a of the stator 9 are magnetized to S.

For this reason, when each tooth of each stator 6 to 9 and the magnetic pole piece on the outer peripheral surface of rotor 2 attract or repel each other and rotate by 1P, the force exerted by stators 6 and 7 on roller 2 and the force exerted by stators 8 and 9 are Since the forces acting on the rotor 2 are equal and opposite to each other, the rotor 2 stops. At this time, as shown in Fig. 4, when only the B current to the coil 12 is cut off, the stators 6 and 7 are demagnetized, and only the stators 8 and 9 continue to be energized, as shown in Fig. 3(e). be done. Therefore, the rotor 2, which had stopped at a position shifted by 1P with respect to each tooth of the stators 6 and 7, counterclockwise until its N pole piece directly faces the tooth 9a of the stator 9 (which is magnetized to S). After rotating in the direction, it will stop again. The rotation angle of the rotor 2 in this case is also shown in Fig. 3(d).
When the coils 12 and 13 are energized B and large, respectively, the teeth 6a of the stator 6 are excited to S, the teeth 7a of the stator 7 are excited to N, and the teeth 8a of the stator 8 are excited to N. In addition, since the teeth 9 of the stator 9 are each excited to S, the motor stops according to the same principle as described above.

As shown in FIG. 4, the number of combinations of current supply directions to the coils 12 and 13 is B and BA in addition to the above.

There are 5 energizations (A, AB, B), and there are 8 energization methods in total. In the apparatus of this embodiment, the rotor 2 is rotated in steps by pulse-controlling the energization to the coils 12 and 13, with each energization being one pulse.

When the electric exposure device of the present invention having the structure as shown in FIGS. 1 and 2 is incorporated into a lens barrel and the lens barrel is attached to a camera body, an AE (with automatic exposure control device) camera is constructed. A part of the control block diagram is shown in FIG.

In FIG. 5, 20 is a photometry circuit, 21 is a light amount setting circuit, 22 is a shutter drive circuit, 23 is a clock pulse generation circuit, 24 is a distribution circuit, and 25 is a motor control circuit.

Next, control operation and aperture blade 1 when taking pictures with the camera
6 will be explained with reference to FIGS. 2 and 5.

When you press the camera's release button f to take a picture, the photometry circuit 20 operates and automatically measures the light.Based on the resulting photometry value, the light intensity setting circuit 21 sets the film sensitivity, required shutter speed, and required aperture. The required number of aperture stages is determined by calculation from the value etc. (In the case of this embodiment, when the rotor 2 rotates one step, the diameter of the orifice 90 is 1/
The shape of the cam ffjQ 15 a and the rotation angle of the rotary ring 17 are designed to change in eight steps.

In the case of the present embodiment, the relationship between the shape of the cam groove 15& and the rotation ring 17 is determined so that the diaphragm changes by one step when the rotor 2 is rotated by 8 steps. ) The number of aperture stages determined by the light amount setting circuit 21 is determined by the distribution circuit 24.
The distribution circuit 24 divides the clock pulse into predetermined steps and inputs the clock pulse to the motor control circuit 25.

The motor control circuit 25 controls the direction of current flowing through the coils 12 and 13 and which coil is energized according to the input signal, and as a result, the rotor 2 is rotated by a predetermined angle in a predetermined direction. (The control of the rotation of the rotor 2 has already been explained, so the explanation will be omitted.) Therefore, the ring 17 is rotated via the pinion 4,
The diaphragm blade 16 pivotally attached to the ring 17
While being rotated around the axis of the ring 17,
It is swung along the cam groove 15m around its own pin 16b. The aperture blade 16 is connected to the pin 16 in FIG.
When the diaphragm is rotated clockwise around b, the diaphragm is opened, and when the pin 16a reaches the outermost position of the cam groove 15, the diaphragm is opened. (When the diaphragm is in the open state, the contact piece 17 supported on the rotating ring 17
Since the conductive pattern 14m on the conductive pattern plate 14 is no longer in contact with the conductive pattern 14m, the control circuit (not shown) electrically detects that the diaphragm has reached the open state.

Note that although the above embodiment relates to an aperture device, it goes without saying that the present invention may be implemented as a shutter device.

〔Effect of the invention〕

As explained above, the electric exposure apparatus of the present invention has a smaller diameter of the rotor 2 and a higher ampere turn of the stator coil than the known electromagnetic drive aperture apparatus, so it is easy to start and stop. This makes it suitable for exposure equipment for large-diameter lenses. However, since the motor protrudes from the end face of the exposure apparatus main body, when it is incorporated into a lens barrel having a zoom mechanism, there is a possibility of generating dead space inside the lens barrel. In the electric exposure apparatus of the present invention, the possibility of creating a dead space is reduced by providing a protrusion on the end face of the exposure apparatus main body, the protrusion having a protrusion length that is at least not longer than the protrusion length of the motor.

[Brief explanation of drawings]

FIG. 1 is a partially exploded perspective view showing a part of the electric exposure apparatus of the present invention, FIG. 2 is an exploded perspective view of the main part of the apparatus shown in FIG. Figure 4 is a diagram for explaining the operation of the motor of the device in Figure 1, and Figure 5
The figure is a block diagram showing part of a control circuit in a camera incorporating the apparatus of FIG. 1. 19...Electric exposure device 19A...Exposure device main body,
19B...Motor 19C...Protrusion 1...
Support member 2...Rotor 4...Pinion
5...Bearing plate 6-9...Stator 10.1
1... Coil iron core 12.13-... Stator coil 14... Conductive pattern plate 15... Cam plate (second support member) 16... Aperture blade (light shielding blade) 17...・Rotating ring (rotating member) 18...Flexible printed board r″1 Agent Teruo Taniyama °1 111. Push” Honda Ko flat ゛ ゛- L-1! - 1゛: Kishi 1) Masaaki゛・: ~, Kotabe Hatani

Claims (2)

[Claims] (1) An exposure apparatus main body that contains parts necessary for exposure such as an optical path hole centered on the optical axis and a light shielding blade for opening and closing the optical path hole, and one end surface of the exposure apparatus main body that is connected to the optical axis. A light-shielding blade driving motor protrudes parallel to the optical axis at an eccentric position, and a light-shielding blade driving motor protruding from the end face of the exposure apparatus main body at a position where the light-shielding blade driving motor does not exist. An electric exposure apparatus comprising: a protrusion having a protrusion length that is at least not longer than the protrusion length of a motor. (2) The electric exposure apparatus according to claim 1, wherein the protruding portion is configured as a case for accommodating an electronic device for the blade drive motor.