JPH0455294Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an automatic focusing lens barrel for a camera.

Conventionally, some lens barrels of this type include a motor as a drive source for driving a focusing lens and a gear train for transmitting the rotation of this motor to a photographing lens. In such lens barrels, the motor and gear train are placed around the optical member (lens), which increases the outer diameter of the lens barrel and reduces operability and portability. In the end, there were problems such as the housing around the motor and gear train having a protruding shape, resulting in an unnatural design.

The present invention solves these shortcomings and improves the support structure of the unit consisting of the motor and power transmission mechanism, the shape of the unit board, etc. to achieve miniaturization.
Another object of the present invention is to provide a structure that can minimize adverse effects on the operability, portability, design, etc. of the lens barrel.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. 1 to 3 show an embodiment of the present invention. This embodiment is an automatic focusing lens barrel that has a motor that drives a focusing lens and a gear train that is a power transmission mechanism. Figure 1 shows
FIG. 3 is a perspective view of an automatic focusing lens barrel. FIG. 2 is an exploded perspective view showing the positional relationship between the gear train unit and the inner cylinder. FIG. 3 shows a sectional view of a fixing part that fixes the gear train unit to the inner cylinder.
The casing 1 shown in FIG. 1 is fixed to a first inner cylinder 5 and a second inner cylinder 6. The casing 1 shown in FIG. Manual distance ring 2
is rotatably provided in the casing 1.
The aperture ring 3 is installed at the rear end of the casing 1. The photographing lens group 4 is installed inside the casing 1. The first inner cylinder 5 shown in FIG. 2 is installed inside the casing 1, and has flange parts 5a and 5e.
It has a cylindrical portion 5d, a convex portion 5b, a convex portion 5c (not shown, but formed on the cylindrical portion 5d at a position symmetrical to the convex portion 5b), and a notch portion 5f. The second inner cylinder 6 is installed in the casing 1 and has a recess 6a and a cutout 6b, and the first inner cylinder 6 is arranged such that the cutout 5f and the cutout 6b form a cylindrical hole. The flange portion 5a of the inner cylinder 5 and the recessed portion 6a fit together. The motor 7 shown in FIG. 1 is fixed to a substrate 17 by a fixing member (not shown) so as to drive a gear train. The gear 8 is fixed to the tip of the output shaft of the motor 7. Large gear 1 of two-stage spur gear 10
The pinion 0a and the small gear 10b are rotatably supported by the shaft 9 and are installed between the base plate 17 and the base plate 18. Large gear 12a and small gear 12 of the two-stage spur gear 12
b is rotatably supported by the shaft 11 and installed between the substrates 17 and 18. The gear 14 is
The substrate 17 and the substrate 1 are rotatably supported on a shaft 13.
It is located between 8. Clutch mechanism 14a
is installed between the gear 14 and the output gear 15. The output gear 15 is rotatably supported by the shaft 13 and meshes with the internal gear 16. The lens driving gear (internal gear) 16 is adapted to drive the focusing lens in the photographing lens group 4.
It is arranged at a predetermined position within the casing 1.
The modules of the output gear 15 and the internal gear 16 are formed larger than the modules of other spur gears, and the height of the tooth tips is higher. The above-mentioned substrate 17,1
8, shafts 9, 11, 13, motor 7, gears 8, 1
0, 12, 14, and 15 constitute a gear train unit. The gear train unit is
The shafts 9 and 1 are connected between the substrate 17 and the substrate 18 as described above.
1 and 13, and these constitute the skeleton of the gear train unit. As shown in FIG. 2, the base plate 17 of the gear train unit has stepped screws 2
The hole 17a is formed to be sufficiently larger than the diameter of the threaded shaft portion 23a (unthreaded cylindrical portion) of No. 3. The first regulating means is constituted by a stepped screw 23 and a blank hole 17a. Angle members 19 and 26 are fixed to both left and right ends of the gear train unit with screws 20 and 28, respectively.

FIG. 3 shows a pair of angle members 19, 2 shown in FIG.
6 shows an enlarged view of surrounding members. In addition, () in Figure 3
The numbers inside indicate the members around the other angle member. Screws 20, 2 to angle members 19, 26
The hole 8 passes through is the stupid hole 19b, similar to the hole 17a.
26b is formed as a long hole extending in the X direction in FIG. The stepped screw 21 shown in FIG.
1a and a threaded portion 21b. The position adjustment means is composed of blind holes 19b, 26b and screws 20, 28. The vibration insulating member 22 has a cylindrical shape, with a ring-shaped groove 22a cut along the circumference and a hole 22b bored in the axial direction of the cylinder. This vibration insulating member is made of silicone rubber or the like. The angle member 19 has a hole 19a and a hole 1.
9b, the inner diameter of the hole 19a is approximately equal to the outer diameter of the groove 22a of the vibration insulating member 22,
The blank hole 19b is formed to be sufficiently larger than the outer diameter of the screw 20. Similarly, the stepped screw 29, the angle member 26, and the vibration insulating member 27 have the same structure as the stepped screw 21, the angle member 19, and the vibration insulating member 22 described above. The vibration insulating means is composed of vibration insulating members 22 and 27. The stepped screws 21 and 29 shown in FIG. 2 are screwed into the convex portions 5b and 5c (not shown) of the first inner cylinder 5 through holes in the vibration insulating members 22 and 27 to elastically support the gear train unit. ing. The stepped screw 23, which is the first regulating means, has the screw shaft portion 23a as described above. Board 1
It is screwed into the flange portion 5e of the first inner cylinder 5 through the hole 17a of No.7. The stepped pin 30 above the shaft 13 is implanted in the substrate 18 and has a pin portion 30a.
have. The buffer member 31 is pivotally supported by a pin portion 30a, and is supported by a cutout portion 5f of the first inner cylinder 5.
It is fitted into a cylindrical hole formed by the cutout portion 6b of the second inner cylinder 6 with a clearance fit. The second regulating means includes cylindrical holes 5f and 6b, a stepped pin 30, a pin portion 30a, and a buffer member 31.

In this embodiment, the support means includes vibration isolation means, a support member, first restriction means, second restriction means, position adjustment means, and the like.

The operation of the automatic focusing lens barrel of the main body embodiment will be described below. In FIG. 1, the manual distance ring 2 is
When a clutch mechanism 14a in the gear train is operated by a manual operation member (not shown) to switch focus alignment from automatic operation to manual operation, focus alignment can be performed manually. This clutch mechanism has a manual distance ring 2 during manual operation.
It is intended to transmit the rotation of a gear (not shown) in the gear train that rotates in response to the rotational force of the gear to the output gear 15, and an attempt was made to rotate the manual distance ring 2 beyond the mechanical limit of close range or infinity. This clutch sometimes slips and protects the gear train. A manual operation member (not shown) releases the connection between the output gear 15 and the gear (not shown), and the output gear 15 and the gear 14 are disconnected from each other.
Switching to automatic operation is possible by connecting the
Here, the operation when performing focus alignment automatically will be explained. The motor 7 rotates its output shaft 7a and the gear 8 fixed thereto in a predetermined direction by the output of a circuit not shown in FIG. The rotation of the gear 8 is transmitted to the large gear 10a of the two-stage spur gear 10, which is rotatably supported on the shaft 9, and the rotation is transmitted to the large gear 10a of the two-stage spur gear 10, which is rotatably supported on the shaft 11, via the small gear 10b. The large gear 12a of the two-stage spur gear 12
The rotation is transmitted to the small gear 12b through the small gear 12b.
The signal is transmitted to a gear 14 which is rotatably supported on a shaft 13. By combining the gears in this way, the rotational speed of the motor is reduced and transmitted at an appropriate speed. A gear 14 rotating around a shaft 13 is connected to a clutch mechanism 14a, and the power from the motor 7 is transmitted to an output gear 15, which rotates an internal gear 16, which rotates the photographic lens group 4 by a pin and cam mechanism (not shown). The focusing lens inside is driven in the optical axis direction to the in-focus position. Furthermore, the gear train unit is
Since it is elastically supported by the first inner cylinder 5 by the stepped screws 21 and 29 and the vibration insulating members 22 and 27, the vibration insulating member is elastically deformed when a force that moves the entire unit is applied. As a result, the relative positional relationship (in the optical axis direction or in the direction perpendicular to the optical axis) between the pitch circles of the output gear 15 and the internal gear 16 may shift. However, even if such a situation occurs, the movement in the optical axis direction is restricted by the stepped screw 23, which is the first regulating means, and the blank hole 17a coming into contact with each other via the buffer members 24 and 25, and the movement in the optical axis direction is restricted. The buffer member 31, which is a regulating means, regulates the movement in the direction perpendicular to the optical axis by coming into contact with the wall surface of the cylindrical hole formed by the cylinders 5, 6, 5f, 6b. It is designed so that it will not become disengaged. Furthermore, by increasing the size of the modules of both gears, the engagement of the gears is further prevented.

In this embodiment, the above two safety measures are taken. The value of this module is at least larger than the module of gears 8, 10, 12, and 14 whose center distances are fixed. By combining the gear train and motor 7 described above into a unit (gear train unit), it becomes possible to unify the system to be subjected to vibration isolation. Therefore, by suppressing the transmission of vibration from this one unit to the lens barrel, the vibration and noise of the entire unit can be suppressed with a simple configuration. The means for supporting the gear train unit at this time will be described in detail. The gear train unit is connected to the convex portions 5b and 5c of the first inner cylinder 5.
(not shown) with stepped screws 21, 29 via vibration insulating members 22, 27. Further, a second cylinder installed on the base plate 18 of the gear train unit is inserted into the cylindrical hole formed by the cutout 5f of the first inner cylinder 5 and the cutout 6b of the second inner cylinder 6. A buffer member 31 serving as a regulating means is fitted. Vibrations caused by vibrations of the motor or collisions between gears of the gear train are absorbed by the gear train unit via the vibration insulating members 22, 27 and the supporting members 21, 29.
Since it is supported by the inner cylinders 5 and 6, it is insulated. Moreover, since the inner cylinders 5 and 6 have the photographic lens group 4 inside and are constrained from the inside, the parts 5a and 6 that support the gear train unit,
The convex portion 5 in the cylindrical portion 5d, avoiding the flange portion of 5e.
b, 5c (not shown).

Therefore, vibrations from the gear train unit are transmitted to the inner cylinder via the vibration insulating member, thereby preventing the generation of noise due to resonance of the inner cylinder. In addition, the gear train unit is connected to the first inner cylinder 5 and the second inner cylinder 5.
If it is directly fixed to the inner cylinder 6 or brought into contact with the casing 1, the vibration components of the gear train unit that are the vibration source will be The vibration frequency and its surrounding components cause the inner cylinders 5 and 6, the casing 1, etc. to resonate and generate noise. Therefore, in this embodiment, as described above, the gear train unit is provided so as not to come into contact with surrounding members that are likely to resonate, and this unit is supported by interposing vibration insulating members between the first and second inner cylinders 5 and 6. As a result, the entire motor and gear train can be insulated from vibration with a simpler configuration than providing vibration insulating members for the motor and each gear.

In this lens barrel, the built-in focusing lens is driven by the motor 7 during automatic operation, and when it reaches a close position or an infinity position, when the lens is out of focus at that position, the focusing lens A reversing device is provided for reversing the drive direction. but,
When this reversing device fails, the focusing lens collides with the mechanical limiter and stops, but the motor still attempts to continue driving. Therefore, at this time, a large torque that decelerates the rotation of the motor is generated in the output gear 15, which attempts to largely displace the entire gear train unit with respect to the lens barrel, causing the meshing of the output gear 15 and the internal gear 16 to become difficult. Displaced in the direction of removal. In addition, when the distance ring is rotated during manual operation to reach the closest or infinite mechanical limit position, and the distance ring is still rotated in a direction exceeding this limit, a large amount of force is applied to the gear train unit via the clutch mechanism. Adds load. Even if such a clutch mechanism fails, the unit tends to be displaced significantly. Furthermore, the unit tends to be displaced by external impact as well. The above-mentioned displacement is regulated by the first regulating means and the second regulating means to ensure normal operation.

Next, the first regulating means and the second regulating means will be explained in detail.

The second regulating means is such that when the gear train unit receives an abnormal force in a direction perpendicular to the optical axis direction due to a failure as described above, the buffer member 31 is 6b, but since the buffer member 31 has elasticity, it deforms itself and absorbs the impact force, preventing large displacement of the gear train unit and not transmitting the impact. to prevent it. That is, the buffer member 31, which is the second regulating means, acts effectively against large displacements of the gear train unit when the above-mentioned force is applied, particularly when a force perpendicular to the optical axis direction is applied.
Note that the buffer member 31 is inserted into the cylindrical hole under normal operating conditions.
Even when the gear train units are in contact with each other, vibration of the gear train unit is prevented by the presence of the buffer member 31.

Next, the first regulating means will be described. The first restriction means is that when the gear train unit receives an abnormal force in the optical axis direction due to the above-mentioned malfunction or when the lens barrel is accidentally hit against a wall or dropped on the floor, the shock absorbing member 24, The board 17 is connected to the stepped screw 2 via 25.
3 and the flange portion 5e, and also restricts the gear train unit from being displaced beyond a certain degree in the optical axis direction. Further, in the stepped screw 23, the screw shaft portion 23a and the hollow hole 17a of the base plate 17 do not come into contact with each other in a normal operating state, so that vibrations of the gear train unit are not transmitted. Then, the stepped screw 23 is
It is screwed into the flange portion 5e of the first inner cylinder 5 with the substrate 17 sandwiched between the buffer members 24 and 25, and like the other shoulder screws 21 and 29, the cylindrical portion 5
Unlike the stepped screw 23 which is screwed in to press the vibration insulating members 22 and 27 appropriately,
are screwed into the base plate 17 of the gear train unit so as not to press the buffer members 24, 25. Therefore, the stepped screw 23 which is the first regulating means
The buffer members 24 and 25 prevent large displacements of the gear train unit, especially when a force in the direction of the optical axis is applied, and the buffer members 24 and 25 normally do not transmit vibrations from the unit to the lens barrel. .

In this embodiment, the gear train unit is attached to the first inner cylinder 5 via the angle members 19 and 26 with the stepped screw 2.
When installed with 1 and 29, the output gear 15 of the gear train unit and the internal gear (lens drive gear) 1
As described above, the angle members 19 and 26 are located in the hole 19, which is a position adjusting means, so that the position of the gear train unit can be set so that the gear train unit can be properly engaged with the gear train unit 6.
b, 26b, and its stupid holes 19b, 2
The gear train unit can be installed in the proper position using screws 20 and 28 through 6b.

In the automatic focusing lens barrel of this embodiment, vibration insulating members 22, 27 and supporting members 21, 2
9 to support the gear train unit on the inner cylinder to insulate vibrations and thereby prevent the generation of noise. By providing the buffer member 31, when an abnormal force is applied, the gear train unit is prevented from large displacement, and the gears are prevented from disengaging, and the output gear of the gear train unit and the gear train unit are prevented from disengaging under normal operating conditions. The position adjusting means can also determine the position of the gear train unit so that the gear train unit meshes normally with the lens drive gear.

As is clear from the above explanation, according to the present invention, the motor and the power transmission mechanism are integrated into a unit, the unit board is formed into an arc shape along the lens barrel, and the central part of the plurality of supports connecting the unit boards is Since at least one of the supports is also used as the support shaft of the gear, it is possible to provide a unit that is extremely compact in both the radial and circumferential directions.

Therefore, even when this is incorporated into a lens barrel, operability, portability, design, etc. are almost never adversely affected.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention, FIG. 1 is a perspective view of an automatic focusing lens barrel, FIG. 2 is an exploded perspective view of a gear train unit and an inner cylinder, FIG. 3 is a partial cross-sectional view of the angle member and the vibration isolation member. Explanation of symbols of main parts, {7...drive source, 8,
9, 10, 11, 12, 13, 14, 15... power transmission mechanism, 17, 18... board, 15... output gear} gear train unit, {22, 27...
Vibration insulation member (vibration insulation means), 21, 29...
Support member, 17a, 23...first regulating means, 5
f and 6b, 30, 30a, 31... second regulating means, 19b, 20, 26b, 28... position adjusting means} supporting means, 16... lens driving gear (internal gear).

Claims (1)

[Claims for Utility Model Registration] (1) A focusing lens, a lens drive gear that is rotatably provided at a predetermined position within a lens barrel and drives the focusing lens, and a lens drive gear that drives the focusing lens, and In an automatic focusing lens barrel including a power transmission mechanism having a plurality of gears transmitted to a lens driving gear, a pair of arc-shaped unit substrates that follow the shape of the lens barrel and a support between the unit substrates are provided. a single drive source unit having a plurality of pillars that hold the drive source and the power transmission mechanism between the unit substrates; a pair of support members for supporting the unit at predetermined positions within the lens barrel, the plurality of gears are arranged in a line along the shape of the unit board, and the gears are arranged near the center of the unit board. . An automatic focusing lens barrel, characterized in that at least one of the pillars supporting between the unit boards also serves as a support shaft of the gear. (2) The utility model registration claim No. 1 is characterized in that the plurality of supports supporting between the unit boards are arranged along the shape of the unit board and in the same row as the arrangement of the gears. Autofocus lens barrel described in section 1).