JPS58181029A - Lens mechanism body provided with electromagnetic device - Google Patents

Abstract

PURPOSE:To drive a moving lens barrel and a light quantity controlling member with high output efficiency, by incorporating an energizing coil in a lens barrel, generating the magnetic fields in the direction parallel to optical axis and the direction vertical to optical axis by switching the conduction direction to the energizing coil, and incorporating them in a tightly sealed state. CONSTITUTION:Ringlike magnets 2a, 2b are inserted into a recessed part 1c of lens barrels 1a, 1b for holding lenses L1-L4, and are held so as to be rotatable by shafts 4a, 4b. Sectors 6a, 6b are fixedly provided on the magnets 2a, 2b, and control opening and closing of the optical path in accordance with turning of the magnet. Energizing coils 10A, 10B are placed on the outside circumferential face of the moving lens barrel, the moving lens barrel is turned and energized counterclockwise by a spring member 18, and the pawl part is engaged with a magnetic member 12 and stops. When electric conduction is executed in the prescribed direction to the energizing coils 10A, 10B, the magnets 2a, 2b are turned and the sector is controlled. Also, the magnetic member 12 is magnetized, the attracting member is attracted and the focusing adjustment is executed, by the prescribed conduction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lens structure equipped with an electromagnetic drive device, and more particularly to an electromagnetic drive device in which a photographing lens and a light amount control member can be driven by energization switching control.

Conventionally, various types of electromagnetic drive devices have been proposed for use in lens structures. For example, a hollow rotor of permanent magnets is arranged around the circumference of the photographing optical path to drive the aperture blades in the lens barrel, and a stator section consisting of an iron core, an excitation coil, etc. is arranged outside the hollow rotor. A technique for rotating a rotor by controlling energization of an excitation coil and controlling the opening and closing operations of the diaphragm blades in accordance with the rotation of the rotor is known, for example, from Japanese Patent Laid-Open No. 50-28852. Furthermore, it has often been proposed to use an electromagnetic drive mechanism as a means for moving the movable lens barrel that holds the photographic lens in a direction parallel to the optical axis within a fixed barrel, and it has been proposed to use a linear motor mechanism for the fixed barrel and the movable lens barrel. Incorporated example (Japanese Patent Application Laid-Open No. 57-20710
No. 1) and a step motor is constructed by providing stepped magnetic pole teeth on the outer periphery of a movable lens barrel that holds the photographing lens, and arranging a stator facing the magnetic pole teeth on the inner periphery of the fixed cylinder. A driving device is also disclosed in Japanese Patent Laid-Open No. 147132A/1983.

On the other hand, in response to technological changes in the materials and shapes of sensitive materials, such as the use of roll film, disk-type film, magnetic tape, and magnetic disks, it is becoming increasingly necessary for photographic equipment itself to respond mechanically. In response to advances in technology and integration, imaging equipment is required to be smaller and have more complex functions. The above-mentioned electromagnetic drive device is a device that drives a single photographic lens in the aperture blade, and the device itself is not organically incorporated into the structure of the photographic lens barrel, but is dependent on the structure of the device itself. It can be said that there are many issues that need to be resolved.

In particular, recent photographic equipment has automatic focus adjustment mechanisms, automatic film loading, and automatic winding mechanisms.

There is a tendency to incorporate a large number of mechanisms such as various safety and warning mechanisms into the main body.
We are looking forward to the development of devices and mechanisms that allow multiple use of different components.

The purpose of the present invention is to incorporate an excitation coil into a lens barrel,
By switching the direction of energization to this excitation coil, two magnetic fields are generated in a direction parallel to the optical axis and in a direction perpendicular to the optical axis, and by this magnetic field, a shape with high manufacturing efficiency and a shape with high output efficiency of the lens barrel illumination are provided. With the goal.

Still another object of the present invention is to provide a lens structure in which light quantity control members such as a shutter and an aperture can be sealed inside a lens barrel. The lens structure for this purpose does not require any adjustment from the outside after the lens barrel is assembled in the manufacturing process, and the sight control mechanism is sealed in the lens barrel to prevent intrusion of foreign substances such as dust and oil. The object of the present invention is to provide a lens structure that can contribute to quality control and cost reduction.

An electromagnetic drive device according to an embodiment of the present invention and a lens barrel incorporating the same will be described with reference to the drawings.

Figure 1 is a perspective view of the main parts of this embodiment, Figures 2 and 5 are
An axial sectional view of the figure is shown.

In the figure, reference numerals 1a and 1b hold photographic lenses L1 to L4, and the optical axis 0. The lens barrels 1a and 1b are provided with recesses 1o on their inner circumferential surfaces, and ring-shaped magnets 2a and 2b are fitted into the recesses of the lens barrels 1a and 1b. The shaped magnets 2a and 2b have an axis 4 parallel to the optical axis.
It is held in the movable lens barrel rotatably about axes at points a and 4b. The ring-shaped magnets 2a and 2b have an optical axis of 0.
-Shutter blade 6a that should control the amount of light passing through 02
6b is fixedly installed, and the opening and closing of the optical path is controlled by shutter blades according to the rotation of the magnets 2a and 2b.

1d is a support arm fixed to the movable lens barrel), and the tip of this support arm is configured to slide on the camera body (not shown) or on the guide rod 8 attached to the base plate K11l.

10A and 10B are excitation coils arranged around the outer periphery of the movable lens barrel. This excitation coil is a line segment parallel to the optical axis.
+2 to 0a, 10a2, 10b, -10, and 10a5, 10a4, 10b, 1, which is a line segment 9 around the optical axis and formed to draw a semicircle along the outer periphery of the photographing optical path.
The excitation coils 10A and 10B are arranged on the outer peripheral surface of the movable lens barrel. The excitation coil 10A.1
The positional relationship between OB and the ring-shaped magnet members 2a and 2b is as shown in FIGS. 4 to 6.

That is, line segments 10a, -10'b, 10a2, 10 in the direction parallel to the optical axis of the excitation coils 10m and 10Bij, respectively.
b2 are parallel to each other, and around the optical axis> line segment 10a, -1
0b, , 10a4, 10b4 are arranged on the outer periphery of the movable lens barrel in a circular manner sandwiching the optical axis, and the ring-shaped magnets 2a,
As shown in FIG. 4, 2b is the line segment 10a, -10b, parallel to the optical axis, and 101L, 10B of the exciting coil 10M.10B.
1) are arranged so that the centers of the axes 41 and 4b are on a line connecting the optical axis.

12ij is a soft iron film arc-shaped magnetic member attached to the movable mirror. 14q (not shown) h An adsorption member made of a magnetic material made of soft iron and attached to the main body or base plate of the main body. 14a is an opening for the optical path, 16 is a locking member for the movable lens barrel, and the fulcrum 16 is attached to the camera body (not shown) or the base plate.
It is pivotally supported so as to be able to swing around a, and one end has a spring member (the third
(Fig.) 18 in the counterclockwise direction, and the claw portion at the other end engages with the movable lens barrel or the magnetic member 12 to stop the movable lens barrel.

20 is a spring member for holding the movable lens barrel at the initial position (close range position). FIG. 7 shows the excitation coil 10A.
An example of a circuit for switching the current direction to -10B is shown.

Reference numeral 30 is a relay switch B depending on the distance of the subject.
This is a circuit that controls the opening and closing of W.

52 is an autofocus near-infrared light source (not shown) 54 is an operational amplifier, 36 is a diode, Tr is a transistor, R1 is a resistor, 58 is a comparator, Tr2 is a transistor, and Elf is a transistor. Said excitation coil 10μ・1
0 B, 1 power supply relay switch. In the circuit 50, when the subject is far away and the reflected light for autofocus does not reach the light receiving element 32, the transistor T r 2 becomes conductive and the relay switch SV is activated. , and t2 are connected, thereby feeding the excitation coils 10M and 10B in one direction as described later.

Reference numeral 40 is a relay switch SW depending on the brightness of the subject.
This circuit performs opening/closing control of No. 2 and switches the current direction of the excitation coils 10A and 10B. 42 is a light receiving element that measures the subject brightness, R4/R5-R6Fi resistor, 4
4 is a comparator, Tr5d and 57') star.

The operating circuit 40 of the relay switch SW is energized to rotate the subject.

Reference numeral 50 indicates a printed board, and hatching portions 50 & -50t arranged in parallel indicate conductive pattern portions.

52 is a sliding plate that can be slid in the direction of the arrow by the release operation of the camera, and this sliding plate 52 has a brush member 52A.
~52D is fixedly installed.

52P, 52P, Fi sliding plate guide bin. The conductive parts 50a to 50f on the printed board 50 are conductive parts for driving and controlling the movable lens barrel in the direction parallel to the optical axis in response to the output signal of the circuit 50, that is, the opening and closing of the relay switch 8W1. That is, from the second start position of the sliding plate 52 based on the release operation of the camera, the autofocus conductive portion SOa~5
During the time it passes through 0f, the excitation coil is 10mm・10
The movable lens barrel 1 is moved by energizing B.

When the brush of the sliding plate 52 further slides and comes into contact with the conductive portions SOP to Sat, the energization to the excitation coils 10A and 10B is switched to the opening/closing control of the light quantity control members 6a and 6b.

Similarly, each conductive part on the printed board 50 and the relay switch SW
,・8W2 and excitation coil 10μ・10. Room B is the 7th
Connect each conductor as shown by the solid line in the figure. A spring 54 biases the sliding plate 52 in the direction of the arrow in response to the release of the camera 2.

Next, the operation of the above configuration will be described.

The movable lens barrel 1 of the embodiment configured as described above is urged toward the close distance side by the spring member 20. When the distance to the object to be photographed is long, no incident signal enters the autofocus light-receiving element 62, the transistor T r 2 becomes conductive, and the relay switch si is closed. The sliding plate 52 slides in the direction of the arrow in conjunction with the release operation of the camera, and the brush members 52A to 52D connect to the conductive portion 50 of the printed board 50! Sliding contact on L to SQf. Due to this sliding contact, the excitation coil 10B Ic is energized in the first direction to the first excitation coil 10A, and in the opposite direction to the first excitation coil IOB, as shown in FIG. Electricity is supplied in the direction of 2. That is, the excitation coil 10m of the irises 1, the second excitation coil 10BO, the optical axis rotation direction line segment 10a,
・10a410'b, ・10'b4. is the center of the optical axis (current flows in the same direction, and the line segments parallel to the optical axis of the coil 10mm/10B are 1011°10b, 1062°10b2
Currents flow in opposite directions. As a result, the magnetic member 12 fixed to the lens barrel is magnetized, and the magnetic member 12 and the attracting member 14 perform an attraction action to drive the movable lens barrel from a close distance position to an infinity position.

When the subject distance is at a position where the photographing lenses L, to L4 can be sufficiently focused, the light receiving element 32 receives the reflected light from the autofocus irradiation device, so that the front-distributed race switch operating circuit 50 remains inactive, and the excitation coil is not energized, and the photographing lens is stopped at a close distance position.

Further, the sliding plate 52 slides in the direction of the arrow, and the brush members 52~62D come into contact with the conductive parts soy~Sat on the printed board 50.

When the subject brightness is lower than a predetermined level, the shutter blades 6a and 6b are moved in the opposite direction. That is, when the subject is dark, the relay switch SW2 is turned on as shown in Figure 7, and the excitation coils 10 and 10B are connected to the first excitation coil 10 and the second excitation coil IOB as shown in Figure 9. The ring-shaped magnet member 2 is energized in the first direction.
The shutter blades a and 2b rotate counterclockwise around the shaft as shown in the 511th line to fully open the shutter blades 6a and 6b. When the brush members 52a, 52t) pass through the conducting portion 507, soh and cut off the current to the excitation coils 10m, 10B, the magnetic poles of the magnet members 2a, 2b exert forces on each other as shown in FIG. Return to position. Conversely, if the brightness of the subject is brighter than a predetermined value and it is necessary to reduce the amount of light passing through the photographic lens, the aperture of the shutter blade must be made smaller as shown in FIG.

In this case, the operating circuit 40 of the relay switch 8W shown in FIG. 7 is activated to attract the movable piece of the relay switch SW. As a result, as shown in FIG. 10, each of the excitation coils 1om and 10B is energized in the second direction opposite to that shown in FIG. The small aperture diameter shown in FIG. 6 is formed. After the operating time of the mist control mechanism has elapsed, when the power to each excitation coil is cut off, the shutter blades S6a and 6b return to the state shown in FIG. 4. When the sliding plate advances from the focusing stroke to the exposure stroke and the shutter blades are opened and closed, each arcuate portion 1 of the excitation core 4 #l0AIOB is activated.
Most of the magnetic flux generated in the magnetic members 12.0a, -10a4, 10'b, -10bQ. The structure is such that the magnetic member 12 and the attracting member 14 do not have an attractive action.

According to the present invention, the focus adjustment unit (lens/lens barrel) and the exposure adjustment unit (shutter blade) can be adjusted by switching the current direction (first and second direction) to the excitation coils 10A and 10B of the set. The drive mechanism can be controlled,
It can be separated as before. Further, in the camera using the present invention, as mentioned above, the photographic lens can be selected at two points, close range and far distance, and the shutter blade for exposure adjustment can also be selected at two points, open or closed.

By providing the energization control circuits 50 and 40, it is possible to provide a simple camera that is programmed in advance according to the distance to the object and the brightness of the object and does not require difficult operations.

Application of the present invention to a two-point switching type camera such as the one described above does not require a complex extension mechanism or focus adjustment device in the structure of the 9-lens lens barrel, resulting in a simple structure and reduced cost. This makes it possible to supply inexpensive cameras to the market. In the above embodiment, if a stepped locking portion 16b is provided at the locking end of the locking member 16 of the movable lens barrel 1 as shown in FIG. 11, it is possible to change the distance at several points. .

Figure 12 (B) to (1') show the above excitation coil IOA・1
A modification of 0B is shown. The shape of the excitation coil shown in FIG. 12(m) is the same as that of the previous embodiment. The shape of the figure is as described above (line segments 101L, 10a2 (10b, 1@) parallel to the optical axis on the outer periphery of the cylindrical movable lens barrel.
), and the line segment around the optical axis is 10 m, -10a4 (10
b, -10b4). (A coil with the shape of the phase diagram has a problem in manufacturing the coil when it is actually incorporated into a product. In other words, the line segment parallel to the optical axis and the line segment in the direction around the optical axis are formed at approximately right angles, so the coil manufacturing process is difficult. There is a good side to Josaku ShiK.

As for the shape of the excitation coil, an elliptical shape (as shown in the figure) or a circular shape (as shown in the figure) is easy to process.

CB).(0) shows an example in which the angle α in (A) is gradually increased and smoothed to approximate the ellipse in (D).

(D) The elliptical excitation coils 10mm and 10B shown in the figure are arranged on the outer periphery of the lens barrel shown in FIGS. In order to form a driving magnetic field, driving control can be performed (B) by switching between the first direction shown in the figure and the opposite second direction using an energization switching circuit.

In order to generate the magnetic field for driving the light amount control member and the magnetic field for driving the movable lens barrel with the same efficiency, (9) the ellipse in the figure should have an ellipse with a ratio of the short axis to the long axis of J.

(2) A rectangular or square excitation coil as shown in the figure and (7) a circular excitation coil as shown in the figure are easy to process and assemble.

Furthermore, the present invention includes magnet members 2a and 2b, and light amount control members 6a and 6b.
The condensed light amount control mechanism from 6b is built into the inside of the lens barrel in a sealed state between the lens barrel and the lens, and is configured to prevent foreign substances such as powder and oil from entering from the outside. We were able to obtain a lens structure that eliminates the need for adjustments and can contribute to cost reduction and improved quality control.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention. FIG. 1 is a perspective view of the main parts. FIG. 2 is a cross-sectional view taken in the two directions of FIG. 1. FIG. 5 is a sectional view taken in the direction B and -B2 of FIG. 1. FIGS. 4 to 6 are cross-sectional views of the lens barrel taken in a direction perpendicular to the optical axis, and each shows the operating positions of the light quantity control members 6a and 6b. FIG. 7 is a circuit diagram for switching the current direction of the excitation coils 10M and 10B. FIG. 8 to FIG. 10 are diagrams showing switching states of the energization direction of the excitation coils 10M and 10B. FIG. 11 is a diagram showing an example in which the amount of movement of the movable lens barrel can be adjusted. 12) to (7) are diagrams showing modifications of the excitation coils 10M and 10B shown in the examples of this collection. 1a, 1b...Movable lens barrels 2a, 2b...Permanent magnets 6a, 6b...Light amount control members 10A, 10B...Excitation coil 12...Magnetic member 14...Adsorption members 50, 40. ... Relay switch actuation circuit applicant Canon Co., Ltd. agent Gi Marushima Shizo i21, -2 ko・k1 upper ball 12th Q e, ρ・ρ2 θ2 θ′ r13ノ (CJ
(9)gu1 (

Claims (1)

[Claims] (1) Place an excitation coil outside or inside the movable lens barrel,
A light amount control member that rotates around an axis parallel to the optical axis is fixed in the movable lens barrel, and includes a nine magnet member, and further includes a magnetic member that is magnetized by the excitation coil, and a magnetic member that is magnetized by the excitation coil. The electromagnetic device is characterized in that the electromagnetic device is configured to apply electricity in one direction to drive the movable lens barrel in the optical axis direction, switch the electricity application direction and apply electricity in a second direction to rotate the light amount control member. lens structure. (w) An excitation coil is disposed inside or outside the lens barrel, a light amount control member is fixed, and a round magnet member is housed in the movable lens barrel so as to be rotatable about an axis parallel to the optical axis; energizing the excitation pulley in a first direction to rotate the magnet member in a 10th rotation direction to operate the light amount control member;
A companion lens structure comprising an electromagnetic device configured to operate the light amount control member in a direction opposite to the operating direction by switching the energization to the excitation coil and energizing it in a second direction.