JP3238463B2 - Electric drive of zoom lens camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zoom lens camera, and more particularly, to an electric driving device for a so-called zoom compact camera.

[0002]

2. Description of the Related Art In a zoom compact camera, zooming is performed by moving a variable power lens group in the optical axis direction by rotating a rotary driving member, for example, a cam ring. The rotation of the cam ring is performed via a motor and a gear train driven by the motor. In this type of camera that requires further miniaturization, where the motor, which is a large component, is placed. Is a matter of concern. There is a similar problem with the final gear of the gear train for rotating the cam ring.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electric drive device in which the motor and / or the final gear of the gear train, which are large parts, can be arranged without increasing the size of the camera body.

[0004]

SUMMARY OF THE INVENTION The present invention, when viewed from the front of the camera,
No matter how close the upper and lower walls are to the zoom lens barrel, there is always a gap between the upper and lower walls of the camera body and the cylindrical part that houses the circular zoom lens barrel due to the curved surface of the barrel. It was made by focusing on the facts. That is, the present invention provides a zoom lens barrel having a rotation driving member and a variable power lens group which advances and retreats in the optical axis direction by the rotation of the rotation driving member; and is located on the optical axis of the zoom lens barrel. A drive unit for a zoom lens camera, comprising: a camera body having a photographing opening and a motor and a gear train mechanism for driving the rotation drive member of the zoom lens barrel to rotate; Upper and lower walls of the body or extensions of these upper and lower walls
Between the virtual wall surface corresponding to and the cylindrical portion that houses the circular zoom lens barrel, and two element storage spaces are formed vertically on one of the left and right sides of the zoom lens barrel. The above-mentioned motor is arranged in one of the element storage spaces, the last gear for rotating and driving the cam ring of the zoom lens barrel is arranged in the other, and a gear train for transmitting the rotation of the motor to the last gear is provided in the zoom lens barrel. It is characterized by having been arranged along.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. 1 and 3 show a main part of an electric driving device of a zoom lens camera according to the present invention. The camera body CB has a substantially rectangular front surface, and upper and lower wall surfaces (outer walls) 40 and 41 are parallel. The camera body CB has a photographing opening 42 and a cylindrical portion 43 for accommodating the zoom lens barrel ZB. The photographing aperture 42 is a well-known one having a center on the optical axis O of the zoom lens barrel ZB, and cuts out a subject image formed by the zoom lens barrel ZB into a rectangle to determine an image forming size on the film.

The upper and lower walls 40, 4 of the camera body CB
Reference numeral 1 is as close as possible to the zoom lens barrel ZB in order to reduce the size. However, the upper and lower walls 40, 4
Even if the distance between 1 and the zoom lens barrel ZB is small, as long as the upper and lower wall surfaces 40 and 41 are planar, the upper and lower wall surfaces 40, 4
1 and the upper and lower sides of the zoom lens barrel ZB.
A gap can be formed by the front circular shape of the zoom lens barrel ZB.

In the illustrated embodiment, notches 44a, 45a are formed in a part of the cylindrical portion 43 between the upper and lower wall surfaces 40, 41 and the upper and lower right sides of the front of the zoom lens barrel ZB to form an element storage space 44. , 45, and a motor 46 is disposed in the element storage space 45, and a final gear 48 of a gear train mechanism 47 driven by the motor 46 is disposed in the element storage space 44.
Is arranged. The upper and lower wall surfaces 40 and 41 constituting the element storage spaces 44 and 45 can be partially cut off. When cutting, the element storage spaces 44 and 45 are used.
Can be formed in the gap between the virtual wall surface of the upper and lower wall surfaces 40 or 41 and the zoom lens barrel ZB.

The gear train mechanism 47 is for transmitting the rotation of the pinion 46a of the motor 46 to the final gear 48.
It is unitized in advance with a large gear support plate 49 together with the motor 46 and is integrally supported.

The final gear 48 drives the cam ring 10 of the zoom lens barrel ZB shown in FIG. 4 to rotate. The final gear 48 is exposed from the notch 12d of the helicoid ring 12 to the inside of the helicoid ring 12, and is provided on the outer periphery of the cam ring 10. It meshes with the formed gear 10d. After the final gear 48 is inserted into the element storage space 44 and the notch 12d, the shaft pin 48b is inserted into the shaft hole 48a as shown in FIG. This shaft pin 48b
Is inserted and supported in a support hole (not shown) of the camera body CB, and the rear end is supported by a support hole 51 of the small gear support plate 50 fixed to the camera body CB.
The gear supporting small plate 50 is formed with an insertion hole 53 for a small gear 52a meshing with the final gear 48 and a stepped gear 52 having a large gear 52b coaxially integrated with the small gear 52a. The inserted stepped gear 52 has its shaft hole 52c rotatably inserted and supported by a support shaft 54 provided in the camera body CB. The large gear 52b meshes with the gear train mechanism 47 and constitutes a part of a gear train mechanism that transmits the rotation of the motor 46 to the final gear 48.

The final gear 48, the gear supporting small plate 50,
In the assembly, the stepped gear 52 and the large gear support plate 49 first support the final gear 48, the shaft pin 48b and the small gear support plate 50 on the camera body CB, and then connect the stepped gear 52 to the final gear 48, and rotatably supported by the camera body CB. After that, a large gear support plate 49 previously supporting the motor 46 and the gear train mechanism 47, a part of which covers the small gear support plate 50, Fix to the camera body CB. The gear support large plate 49 is formed with a shaft hole (not shown) that engages with the support shaft 54, and the gear support large plate 49 is put on the gear support small plate 50 so that the stepped gear 5 is formed.
2 is prevented and the gear train is completed.

The final gear 48 rotates the cam ring 1 by its rotation.
0 is rotationally driven, and as a result, zooming of the zoom lens barrel ZB is performed. In the present invention, the structure of the zoom lens barrel ZB itself is not limited as long as the above-described zoom function can be obtained, but the structure of the example shown in FIGS. 4 to 7 will be described.

A helicoid ring 12 is inserted and fixed to the cylindrical portion 43 of the camera body CB. A male helicoid 10a formed on the outer peripheral surface of the cam ring 10 is screwed into the female helicoid 12a of the helicoid ring 12. . Inside the cam ring 10, a female helicoid 10b and an inner cam groove 10c are formed.
Male helicoid 13a is screwed. At the rear end of the cam ring 10, light shielding plates 25 and 26 are located, and positioning recesses 25a formed on the light shielding plates 25 and 26 are formed.
The guide portion 23b of the straight guide 23 fixed to the camera body is fitted into the positioning recess 15b of the straight guide ring 15 and the positioning guide 26b. Light-shielding plates 25 and 26 are fixed to the rectilinear guide ring 15 with their positioning recesses 25a and 26a aligned with the positioning recesses 15b, and the cam ring 10 is rotatably fitted to the rectilinear guide ring 15. Is done. The rectilinear guide 23 is fixed to a fixing member 24 fixed to the camera body by a screw 22 so that the guide portion 23b projects along the optical axis direction.

The front lens barrel (front frame) 13 is guided straight by a straight guide portion 15a of the straight guide ring 15. The front lens barrel 13 has a rear end of an annular shutter unit 16. The shutter holding frame 13c to which the portion is fixed is fixed. Further, a helicoid ring 17 provided integrally with the inner peripheral portion of the shutter unit 16 has a front group lens L1.
Are held together by a front group lens frame 18. The shutter unit 16 connects the drive pin 16 a to the front group lens frame 18.
The driven pin 18a is integrated with the driven pin 18a. As is well known, the drive pin 16a is rotationally driven by an angle corresponding to a distance measurement signal from a distance measurement device, and this rotation is
a to the front lens group 18 and the front lens group 1
8 (front lens group L1) is rotated and moved in the optical axis direction to perform focusing. Further, the shutter unit 16 opens and closes the shutter blade 16b according to the luminance signal of the subject. In addition, 13f in FIG. 4 is a lens aperture.

A rear group lens frame (rear group frame) 19 to be inserted into the cam ring 10 holds the rear group lens L2 and has a cam pin 19a projecting in the radial direction. The cam pin 19a is fitted in the inner cam groove 10c of the cam ring 10. In addition, the rear lens group frame 19 is
b, the rectilinear guide 19b is engaged with a rectilinear guide (not shown) of the front lens barrel 13 (shutter holding frame 13c). The front lens barrel 13 includes a linear guide ring 15.
, And the rear lens group frame 19 is
Therefore, the front lens barrel 13 and the rear lens frame 19 are both guided straight in the optical axis direction.

The cam ring 10 has a rear portion,
Male helicoid 10a and a plurality of parallel gears 10
d is formed. The gear 10d has a cam ring 1
0, which is inclined in the same direction as the direction of the crest of the male helicoid 10a, and between each gear 10d, a single thread 1 of the male helicoid 10a.
0a 'is formed. In other words, male helicoid 1
0a is a single thread 10 in a part of its circumferential direction.
The gear 10d is cut except for a ', and a gear 10d is provided at the cut portion. In this embodiment, the helicoid 10a is
It is a three-start thread, and a gear 10d is provided at the two cut ends. The axially formed length s of these male helicoid 10a, single thread 10a 'and gear 10d
Are the same.

A cam ring 10 is provided on the inner surface of the helicoid ring 12.
Female helicoid 12 corresponding to the male helicoid 10a, the single thread 10a 'and the triple gear 10d, respectively.
a and a relief groove (not shown) are formed. That is, the gear 10d is connected to the male helicoid 10a (the screw thread 10a).
a ') and the female helicoid 12a, the cam ring 10
When it rotates, it moves in the escape groove in a non-contact manner.

Further, the final gear 48 facing the inside of the helicoid ring 12 from the notch 12d of the helicoid ring 12 is engaged with the gear 10d as described above. This final gear 48
Has an axial length capable of meshing with the three gears 10d at the same time, but at the front moving end and the rear moving end of the cam ring 10, it meshes with only the rearmost and front gears 10d, respectively. FIG. 7 shows this relationship. In FIG. 7, instead of changing the position of the cam ring 10 in the optical axis direction, the position of the final gear 48 in the same direction is changed. Of course, in fact, the cam ring 10 moves in the optical axis direction, and the gear 48 does not move in the same direction.

In the zoom lens camera having the above-described configuration, when the motor 46 is driven to rotate in the forward and reverse directions, the rotation of the pinion 46a is transmitted to the final gear 48 via the gear train mechanism 47 and the stepped gear 52. The rotation of the final gear 48
The cam ring 10 is transmitted to the cam ring 10 via d, and as a result, the cam ring 10 itself moves in the optical axis direction according to the relationship between the male helicoid 10a and the female helicoid 12a. At the same time, the front group lens barrel 13 (front group lens L1) moves linearly in the optical axis direction due to the screwing relationship between the female helicoid 10b and the male helicoid 13a and the linear guide mechanism between the shutter holding frame 13c and the linear guide ring 15. When the cam ring 10 rotates, the cam groove 10c on the inner surface thereof and the cam pin 1 provided on the rear group lens frame 19 are formed.
9a, the rear lens frame 19 and the straight guide ring 1
The rectilinear guide mechanism 5 moves the rear lens group frame 19 (rear lens group L2) in the optical axis direction to perform zooming.

[0019]

As described above, the present invention utilizes the curved surface of the lens barrel between the upper and lower walls of the camera body or its virtual wall when the camera is viewed from the front and the circular zoom lens barrel. Thus, an element storage space is formed, and the motor is stored therein, which can contribute to downsizing of the camera.

[Brief description of the drawings]

FIG. 1 is a front view of a main part showing an embodiment of an electric driving device for a zoom lens camera according to the present invention.

FIG. 2 is a front view illustrating the gear train support plate.

FIG. 3 is an exploded perspective view of FIGS. 1 and 2;

FIG. 4 is an exploded perspective view of the entire zoom lens barrel driven by the electric drive device of the present invention.

FIG. 5 is a sectional view illustrating the upper half in a wide state and the lower half in a telescopic state.

FIG. 6 is an enlarged sectional view showing an engagement state of a cam pin with a cam groove in the apparatus shown in FIGS. 4 and 5;

FIG. 7 is a developed view showing a meshing state of a final gear of a gear train of the electric drive device and a gear of a cam ring.

[Description of Signs] CB Camera Body ZB Zoom Lens Barrel 10 Cam Ring (Rotation Driving Member) 10d Gear L1 Front Group Lens L2 Rear Group Lens 40 41 Upper and Lower Wall Surfaces 42 Shooting Opening 43 Zoom Lens Barrel Storage Tube 44 44 Element Storage space 46 Motor 47 Gear train 48 Final gear 48a Shaft hole 48b Shaft pin 49 Large gear support plate 50 Small gear support plate 52 Stepped gear

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-186330 (JP, A) JP-A-4-285924 (JP, A) JP-A-5-80244 (JP, A) JP-A-59-1984 40630 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G02B ⁷ /02-7/105 G03B 17/02

Claims (1)

(57) [Claims] 1. A zoom lens barrel having a rotary drive member and a variable power lens group which advances and retreats in the optical axis direction by the rotation of the rotary drive member; and an imaging device located on the optical axis of the zoom lens barrel. A camera body having an opening and having a motor and a gear train mechanism for rotationally driving the rotary drive member of the zoom lens barrel; a camera body when the camera is viewed from the front; Between the upper and lower wall surfaces or a virtual wall surface corresponding to an extension surface of the upper and lower wall surfaces and the cylindrical portion that houses the circular zoom lens barrel, and is vertically positioned on one of the left and right sides of the zoom lens barrel. Forming two element storage spaces, disposing the motor in one of the upper and lower element storage spaces,
A zoom lens, comprising: a second gear that rotatably drives a cam ring of the zoom lens barrel; and a gear train that transmits rotation of the motor to the last gear is arranged along the zoom lens barrel. Electric drive for camera.