JP2880760B2 - Camera zooming equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a camera zooming device, and more particularly to a support structure for a drive motor thereof.

“Prior art and its problems” The electric zoom lens transmits a rotation of a drive motor to a zooming member, for example, a cam ring via a gear train, and a cam groove provided in the cam ring causes the variable power lens group to move in the optical axis direction. And zooming. With this electric zoom lens,
During the zooming, a zooming sound (noise) due to the meshing of the gear train is inevitable.

"Object of the Invention" An object of the present invention is to reduce this zooming sound.

"Summary of the Invention" The present inventor has found that among the places where the zooming noise is generated, in particular, the first stage gear meshing portion transmitting the rotation of the drive motor, that is, the meshing portion of the pinion of the rotation shaft of the drive motor and the gear meshing with this They found that the noise was loud, and developed a drive motor support structure that can reduce the sound of the first-stage meshing portion.

The present invention provides a camera zooming device that transmits the rotation of a drive motor to a camera zooming member through a gear train in which the positional relationship between a plurality of constituent gears is fixed.
A gear train in which a drive motor is mounted on a support substrate of the motor so as to be rotatable about an eccentric shaft eccentric to the rotation shaft of the motor, and a pinion provided on the rotation shaft of the drive motor meshes with the pinion. In the direction approaching the inside gear,
This drive motor is characterized by being urged to rotate about an eccentric shaft.

According to this configuration, the pinion of the drive motor is constantly urged toward the gear that meshes with the pinion, so that the generation of abnormal noise at the time of engagement between the two is reduced. Accordingly, the zooming sound of the first-stage meshing portion, which is particularly noisy, is reduced, and the zooming noise is reduced as a whole. The urging force applied to the drive motor is within the range where the rotation of the pinion is smoothly transmitted to the gear.
In addition, it is determined that no harmful load is applied to the motor.

The “drive motor” in the present invention includes a drive motor having a speed reducer, and it is only necessary that a pinion is provided on an output shaft (rotation shaft).

"Examples of the Invention" The present invention will be described below with reference to illustrated examples. FIG. 4,
FIG. 5 is an overall view showing an embodiment of a camera zooming device according to the present invention. The cam ring 11 rotatably supported around the optical axis includes a front group cam groove 12 and a rear group cam groove 13.
And a flash cam groove 14. Cam groove for front group
Pinions provided in a front lens group and a rear lens group (both not shown) are fitted into the cam groove 12 and the rear group cam groove 13, respectively. As the cam ring 11 rotates, these lens groups move in the optical axis direction. Zooming is done. The pin 18 of the moving block 17 guided by the optical axis direction rod 16 is fitted in the flash cam groove 14. This moving block 17
Through an interlocking lever 20 pivotally mounted on a shaft 19, the flashlight emitting block 21 is interlocked with and moved to a position corresponding to the focal length.

A sector gear 22 is fixed to the outer periphery of the cam ring 11, and the sector gear 22 is attached to the final gear of the gear box 30.
31 are engaged. The gist of the present invention is a structure for supporting the drive motor 32 in the gear box 30, and details thereof are shown in FIGS.

The gear box 30 has a pair of support substrates 34 integrated by connecting columns 33. The drive motor 32 is supported on one of the pair of support substrates 34 by a stepped screw 35. The stepped screw 35 is eccentric to the pinion 32a provided on the rotation shaft of the drive motor 32 (upward in the illustrated example).
And has a step 35b and an external thread 35c following the head 35a. The stepped portion 35b is rotatably fitted into a support hole provided in the support substrate 34, and the male screw portion 35c is screwed and fixed to the drive motor 32. Can rotate. The axial length of the step 35b is
4, a cushioning material (not shown) such as rubber is inserted into a gap s (FIG. 3) formed between the support substrate 34 and the driving motor 32. By forming a gap between the drive motor 32 and the support substrate 34 in this way, it is possible to prevent the vibration noise of the drive motor 32 from being enlarged by the support substrate 34.

The base of the leaf spring 44 is fixed to the support substrate 34,
The tip pressing portion 44a of the leaf spring 44 is in contact with the drive motor 32. This leaf spring 44 gives a rotational moment in the direction of FIG. 1A around the stepped screw 35 to the drive motor 32 to bring the pinion 32a closer to and mesh with the first gear 36a of the gear train in the gear box 30. Works.

That is, the first gear 36a meshed with the pinion 32a of the drive motor 32, the first gear 36a
A second gear 36b coaxial with the third gear 37a meshing with the second gear 36b, and a fourth gear 37 coaxial with the third gear 37a
b, a fifth gear 38a meshed with the fourth gear 37b, a sixth gear 38b coaxially integrated with the fifth gear 38a, a seventh gear 39a meshed with the sixth gear 38b, and a fifth gear coaxially integrated with the seventh gear 39a. The eighth gear 39b, and the eighth gear 39b and the sector gear 22
The above-mentioned final gears 31 meshing with are supported.
The rotation of the fifth gear 38a is also transmitted to the slit disk 42 of the photo interrupter 41 via the branch gear 40. The photo interrupter 41 detects the rotation position of the sector gear 22, that is, the focal length, by detecting the passage of the slit disk 42 through the slit 42a.

When the drive motor 32 is driven in the forward and reverse directions, the present device having the above-described configuration shifts the first gear 36a meshing with the pinion 32a from the second gear 36a.
The gear train of 36b, third gear 37a,..., Eighth gear 39b, and final gear 31 rotates in the forward and reverse directions, and cam ring 11 integrated with sector gear 22 rotates in the forward and reverse directions to perform zooming. According to the present invention, a rotational moment is given to the drive motor 32 by the leaf spring 44, and the rotational moment
The pinion 32a has a tendency to approach the first gear 36a. For this reason, the noise level when rotation is transmitted from the pinion 32a to the first gear 36a is reduced as compared with a case where such a rotation moment is not applied. That is, the meshing gap between the pinion 32a and the gear 26a is smaller than in the case where such a rotational moment does not exist, and therefore, the noise level of rotation transmission is reduced.

If the rotational moment given by the leaf spring 44 is too large, an excessive load is applied to the drive motor 32 to hinder smooth rotation. Therefore, an appropriate magnitude is set within a range that does not hinder the smooth rotation of the drive motor 32.

[Effects of the Invention] As described above, according to the present invention, in a zooming device of a camera that transmits rotation from a pinion of a drive motor to a gear meshing with the pinion, a noise generation level when transmitting rotation from the pinion to the gear Can be reduced, and the zooming sound can be reduced to a low level as a whole.

[Brief description of the drawings]

1 is a perspective view of a main part showing a support structure of a drive motor according to the present invention, FIG. 2 is an enlarged front view of a gear box, FIG. 3 is a plan view of the same, FIG. 4 and FIG. It is the front view and top view which applied this invention to the zooming apparatus. 11 cam ring, 12 front group cam groove, 13 rear group cam groove, 14 strobe cam groove, 21 strobe flash block, 22 sector gear, 30 gear box, 21
…… Final gear, 32 …… Drive motor, 32a …… Pinion, 3
4 ... Support substrate, 35 ... Stepped screw (eccentric shaft), 35a ... Head, 35b ... Step, 35c ... Male thread, 36a ... First gear, 36b, 37a, 37b, 38a, 38b, 39a, 39b ... gear, 40
… Branch gear, 41… photo interrupter,… slit disk, 42a… slit, 44… leaf spring (rotation biasing means), 44a… tip pressing part.

Claims (1)

(57) [Claims] 1. A camera zooming device for transmitting the rotation of a drive motor to a zooming member of a camera via a gear train in which the positional relationship of a plurality of constituent gears is fixed. A direction in which a pinion provided on a rotation shaft of the drive motor approaches a gear in the gear train that meshes with the pinion so as to be rotatable about an eccentric shaft eccentric to the shaft. To
A zooming device for a camera, comprising means for urging the drive motor about the eccentric shaft.