JP2625630B2 - Light control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light amount control device for a camera or the like, and more particularly to a light amount control device suitable for a video camera which has excellent productivity and improved strength.

[0002]

2. Description of the Related Art An example of a conventional light quantity control device is shown in FIG. In the figure, 1 is a drawn ground plate, 2 is a yoke, 3A,
3B is a coil part, 4 is a flexible printed wiring board, 5
Is a Hall element, 6 is an insulating tape, 7 is a magnet, 8 is a drive arm, 10 and 11 are aperture blades, 12 is an ND filter, 13 is an aperture cover, 14 is a cap, and 15 is a shaft.

[0003] The assembly of the light quantity control device composed of the above members is generally performed as follows. That is,
The upper part of the shaft 15 to which the magnet 7 is fixed is inserted into the upper bearing 1a provided on the squeezed base plate 1, and the drive arm 3 is press-fitted or bonded to the upper end of the shaft. Then, a return spring 9 is attached to the drive arm 8, and the aperture blades 10 and 11 are attached to the drive arm 8. In the lower part of the base plate, coils 3A, 3B, insulating tape 6, and yoke 2 are arranged around magnet 7,
The lower end of the shaft 15 is inserted into the lower bearing 14 a provided on the cap 14, and the cap 14 is fixed to the drawn ground plate 1 with screws 16.

Accordingly, the drive arm 8 and the shaft 15 are
The structure cannot be assembled unless both are separated, and one end of the shaft is finally inserted into the hole of the drive arm and fixed by press-fitting or bonding.

[0005]

In the conventional example, the assembly as described above with reference to FIG. 3 was performed. Accordingly, since the drive arm 8 and the shaft 15 are separate members, there are the following drawbacks.

(1) A step of connecting the drive arm and the shaft is required, which increases the number of assembling steps.
(2) At a minimum, the two members are required, and the component cost increases. (3) The coupling of the two members is performed by knurling the shaft tip, press-fitting into the hole of the drive arm, and controlling the strength by press-fitting. It is necessary to control the fixing strength (rotational strength) of the two members. An object of the present invention is to solve the above problems.

[0007]

Means and Action for Solving the Problems Claim 1 of the present application
The light amount control device according to the invention described in (1), supporting the diaphragm blades on the diaphragm ground plate, driving the diaphragm blades by a drive arm rotated by a servo motor, and controlling the amount of light passing through each diaphragm aperture of the diaphragm ground plate and the diaphragm cover. In a variable light amount control device, a shaft having a driving pin for transmitting a driving force to the diaphragm blade, a spring retaining pin for retaining a return spring of the driving arm, and a shaft-receiving portion at both ends. The drive arm is formed by integrally molding the drive arm and the drive unit. By such means, the number of assembling steps and the cost of parts can be reduced, and the rotation strength can be stabilized and improved. The light quantity control device according to the invention described in claim 2 of the present application supports the diaphragm blade on the diaphragm base plate, drives the diaphragm blade by a drive arm rotated by a servo motor, and controls the light amount passing through the diaphragm aperture of the diaphragm base plate. In the light quantity control device, the drive arm is inserted into an arm portion having a drive pin engaged with the aperture blade and a hole provided in a cylindrical permanent magnet, and serves as a rotation axis of the servo motor. It is characterized in that it is integrally formed with a shaft portion having a fitting portion, and by such means, the number of assembly steps and the cost of parts are reduced.

[0008]

1 and 2 show the features of the present invention best. 1 and 2, reference numeral 1 denotes a drawn ground plate,
1a is a lower bearing, 1b is a relief hole for terminal pins of coils 3A and 3B described later, 1c is a positioning hole, and 1d is a coil 3
A, a hook for positioning or fixing 3B, 1e is a guide or positioning pin, 1f is a dowel, 1g, 1h,
1j, 1k is a guide pin, 1i is a hook claw, 1r is a hole,
1m is the aperture diameter, 1n is the recess for storing the aperture blades, 1p
Is a recess that houses the servomotor or yoke,
These elements 1 a to 1 p are provided on the drawn ground plate 1. The drawn ground plate 1 and the drawn cover 13 are preferably made of anodized aluminum, plastic reinforced with carbon fiber, or the like. 2 is a yoke having a concave portion 2a, 3A and 3B are coils, 3Aa, 3Ab, 3Ba,
3Bb is provided on each of the coils 3A and 3B, and is a projection which fits into the positioning hole 1c of the drawing ground plate, 4 is a flexible printed wiring board, 5 is a hall element, 6 is an insulating tape, 7
Is a magnet having a hole 7a.

Reference numeral 8 denotes a drive arm with a shaft, and a shaft portion 8 serving as a rotation axis of an arm portion 8-1 and a servomotor.
-2, and are manufactured by integral molding of these two. The drive arm 8 is preferably formed integrally by injection molding using a hard engineering plastic, but may be formed by other known molding means.
The shaft portion 8-2 includes a bearing portion 8a fitted to the bearing 1a, a fitted portion 8b fitted into the hole 7a of the magnet 7 by press-fitting or bonding, and a spring wound portion for winding a return spring 9. 8c, a flange portion 8d for pressing the return spring 9, a bearing portion 8e fitted to an upper bearing 13a described later, and a projection 8i for press-fitting. The arm portion 8-1 is provided with a driving slot 1 for the aperture blades 10 and 11 described later.
Drive pin 8 which engages with 0a, 11a to transmit the driving force
f, 8g, and a spring retaining pin 8h for retaining the return spring 9 described later.

Reference numeral 9 denotes a return spring, and reference numerals 10 and 11 denote aperture blades. The blade 10 includes a driving slot 10a and a guide slot 1
0b and 10c, and similarly, the blade 11 has a driving slot 11a and guide slots 11b and 11c. 1
2 is an ND filter. Reference numeral 13 denotes an aperture cover, an upper bearing 13a, a convex portion 13b for protecting the shaft portion, and a claw 1i.
The hole 13c, the positioning hole 13d, and the aperture 13e are provided at four positions so as to be hooked to the hole.

A light quantity control device according to one embodiment of the present invention
It is composed of the above-described members, and these members are assembled as follows.

The insertion portion 8b of the drive arm 8 around which the return spring 9 is wound is fixed to the hole 7a of the magnet 7 by press-fitting or bonding, the magnet is sandwiched by the coils 3A and 3B, and the hole blocking 5 is soldered or the like. The flexible printed wiring board 4 is fixed to one of the coils 3A or 3B with an adhesive or a double-sided tape, and is fixed with an insulating tape 6 so that no gap is formed between the bobbins. In this case, the tape outer dimensions are such that there is no gap between the tape outer diameter and the inner diameter of the yoke 2. Next, the yoke 2 is inserted into the recess of the drawing base plate, and the claw 1d of the drawing base plate 1 is
And fixedly positioned. In this case, the bearing 1a has a mortar shape, and guides the shaft tip smoothly to the bearing 1a. Further, as described above, the servomotor is formed mainly by the yoke, the coil, and the magnet.

The flexible printed wiring board 4 has a hole 1r.
Each of the holes 1c is provided with a corresponding one of the projections 3 of the coils 3A and 3B.
Aa and 3Ba, 3Ab and 3Bb are engaged to position the coil. The dowel 1f engages with the hole 2a of the yoke 2 for positioning. As described above, the servo motor is fixed to the drawing ground plate 1. Next, one end of the return spring 9 is locked to a locking pin 8h of the drive arm 8 and the other end is locked to a locking portion (not shown) of the squeezed base plate 1, so that the drive arm 8 is in an auto-closed state. You will take a posture. Next, an aperture blade 10 and an aperture blade 11 to which an ND filter is adhered.
The guide pins 1g, 1h, 1j, and 1k of the squeezed base plate 1 are inserted into the guide slots 10b, 10c, 11b, and 11c, respectively.
The drive pins 8f and 8g of the drive arm 8 are inserted into 1a, and the respective aperture blades 10 and 11 are stored in the recesses of the aperture base plate 1.

Finally, the fitting shaft portion 8e of the drive arm 8 is fitted to the bearing 13a of the diaphragm cover 13, and
Insert the pin 1e of the drawn ground plate 1 into the hole 13d
The hook c is hook-engaged with the hook claw 1i, and the aperture base plate 1 and the aperture cover 13 are fixed to each other. In this case, the distal end of the shaft portion 8e is largely chamfered or rounded to facilitate insertion, and is protected by the convex portion 13b.

The embodiment of the present invention is constructed and assembled as described above. By using the same part for the shaft and arm of the drive arm, the number of parts and the number of assembling steps can be reduced. As a result, the manufacturing cost of the light quantity control device can be reduced. In addition, improvement of rotary strength,
Stabilization is achieved.

[0016]

According to a first aspect of the present invention, there is provided a light amount control device that supports a diaphragm blade on a diaphragm base plate, drives the diaphragm blade by a driving arm rotated by a servomotor, and controls the diaphragm base plate and the diaphragm base plate. An amount of light passing through each of the apertures of the aperture cover, wherein an arm portion having a drive pin for transmitting a driving force to the aperture blade, and a spring retaining pin for retaining a return spring of the drive arm; By forming the drive arm by integrally molding a shaft having bearings at both ends, the number of parts and the number of assembly steps can be reduced, the manufacturing cost can be reduced, and the drive arm with a shaft can be reduced. And the operation as the light amount control device is stabilized. The light quantity control device according to the invention described in claim 2 of the present application supports the diaphragm blade on the diaphragm base plate, drives the diaphragm blade by a drive arm rotated by a servo motor, and controls the light amount passing through the diaphragm aperture of the diaphragm base plate. In the light quantity control device, the drive arm is inserted into an arm portion having a drive pin engaged with the diaphragm blade and a hole provided in a cylindrical permanent magnet, and serves as a rotation axis of the servo motor. By integrally forming the shaft part with the fitting part, the number of parts and the number of assembly steps can be reduced, the manufacturing cost can be reduced, and the strength of the drive arm with the shaft can be improved. Operation becomes stable.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an example of a configuration of a light quantity control device embodying the present invention.

FIG. 2 is a perspective view of a drive arm in the embodiment.

FIG. 3 is a configuration diagram showing an example of a conventional light amount control device.

[Explanation of symbols]

1: Draw ground plate, 2: Yoke, 3A, 3B: Coil, 4 ...
Flexible printed wiring board, 5 ... Hall element, 7 ... magnet, 8 ... drive arm, 8-1 ... arm part, 8-2
... Shaft part, 8a, 8e ... Bearing part, 8f, 8g ...
Driving pin, 8h: Spring retaining pin, 9: Return spring,
10, 11 ... diaphragm blades, 13 ... diaphragm cover

Claims (2)

(57) [Claims] An aperture blade is supported on an aperture base plate, the aperture blade is driven by a drive arm rotated by a servomotor, and the amount of light passing through each aperture of the aperture base plate and the aperture cover is made variable. in the control unit, and an arm portion having a drive pin for transmitting the driving force to the restrictor blade, and the spring hooking pin for engaging the return spring of the drive arm, and a shaft portion that have a target bearing portions at both ends A light quantity control device characterized in that a drive arm is formed by integrally molding the above. 2. An aperture blade is supported on an aperture base plate, and a servo
The diaphragm blade is driven by a drive arm rotated by a motor.
Drives the root to vary the amount of light passing through the aperture of the aperture base plate
In the light amount control device, the drive arm is
An arm portion having a drive pin engaged with the blade,
The servo motor is inserted into a hole provided in a permanent magnet
The shaft part with the insertion part that becomes the rotation axis of the
A light quantity control device characterized by comprising: