JPS5961824A - Zoom lens barrel - Google Patents

Abstract

PURPOSE:To eliminate the play of an operating ring due to back crush between a zooming gear and an output transmission gear by providing the output transmission gear which transmits the output of a zoom motor to the zooming gear while engaging the zooming gear, and a rotation specifying means which specifies the rotation of the zooming gear. CONSTITUTION:When movable contact pieces 14a and 14b of a zooming switch 13 are brought into contact with terminals 15a and 15b, the zoom motor 4 rotates forward by a DC power source 16, the iron core of a plunger 8 moves from a nonoperation position to an operation position, and a friction generation member 11 fixed to a rotation specifying arm 10 is disengaged from the zooming gear 2. When the zooming switch 13 is turned off, the zoom motor 4 stops, the iron core of the plunger 6 returns to the nonoperation positon, and the friction generation member 11 engages the zooming gear 2. Further, when the movable contact pieces 14a and 14b of the zooming switch 13 are brought into contact with terminals 17a and 17b, the zoom motor 4 reverses its revolution to move the iron core 7 of the plunger 6 to the operation position, so that the friction generation member 11 is disengaged from the zooming gear 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a zoom lens barrel used in an imaging camera or the like.

Conventional configuration and its problems In general, when performing electric zooming, a conventional zoom lens barrel requires a zooming gear attached to an operating ring exposed to the outside, and an output transmission gear that transfers the output of the zoom motor. The structure is such that zooming is performed by meshing with the lens. Furthermore, when manually zooming with such a zoom lens barrel, an appropriate amount of friction is created between the zooming gear, whose rotation is restrained by the output transmission gear that functions as a stop member, and the operating ring. Gives smooth rotational operability to the ring. However, since there is no friction due to the amount of backlash that exists in the gear transmission mechanism, it causes rattling in the direction of one rotation, and the lens barrel may be accidentally hit against something or touched by hand. The image becomes unstable each time, and the value of the video recorded by the video camera decreases.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and provides a zoom lens barrel that suppresses wobbling of the zoom lens barrel due to backlash and can be operated with stable friction even when zooming manually. The purpose is to

Structure of the Invention In order to achieve the above object, Teimei's zoom lens barrel has the following features:
A control ring for zooming, a zoom motor for driving the control ring, a zooming gear mounted concentrically and relatively rotatably on the control ring, and a zooming gear meshing with the zooming gear to drive the zoom. This configuration includes an output transmission gear that transmits the output of the motor to a zooming gear, and a rotation restriction means that restricts rotation of the zooming gear.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In Figure 1, (1) is a zooming operation ring, (2
) is the zooming gear, (3) is the output transmission gear, (4) is the zoom motor, and (5) is the friction member. When the zoom motor (4) is operating, the rotational force of the zoom motor (4) is output. It is transmitted to the zooming gear (2) via the transmission gear (3).

The operating ring (1) is rotated by the frictional force of the friction member (5).
Ru.

In addition, a rotation regulating arm aO is rotatably supported by a support shaft (9) on a support shaft (8) of an iron core (7) of a plunger (6) that operates in conjunction with a zoom motor (4). is slidably guided, and the iron core (7) is moved from the non-operating position shown in the diagram to the position shown in FIG.
(not shown), the W is fixed to the contact portion of the rotation regulating arm 00 with the zooming gear (2).
The sardine generating member 11) is in a non-coupled relationship with the zooming gear (2) fx f * When the zoom motor (4) is not operating, the passage to the plunger (6) is blocked and
is returned to the non-operating position by the compression spring 0, and the friction generating member (111) fixed to the rotation regulating arm α0 is crimped to the zooming gear (2) to regulate the rotation of the zooming gear (2). The friction generating member (11) may be made of synthetic resin (for example, rubber) or other material having flexibility.

Figure 2 is a 10-step diagram of the drive rotation of the zoom motor (4) and plunger (6).
Connect the oru6 contact piece (14&X14b) to the terminal (15a) (1
5b) When it comes into contact with the VC liquid, the zoom motor (4) rotates forward due to DC t#α0, and the iron core of the plunger (6) (
7) moves from the non-operating position to the operating position, and the friction generating member (11) fixed to the rotation regulating arm C1O turns off the zooming switch Q (to), which is not coupled to the zooming gear (2). Then, the zoom motor (4) stops, the iron core (7) of the plunger (6) returns to the non-operating position by the compression spring, and the friction generating member (11) is compressed by the zooming gear (2). Zooming gear (2)
), and also connects the movable contact C14EL) <14b>, which is responsible for the zooming switch, to the terminal (17aX17b
) vc contact salut, X-mumo-6t f4) t
d.

The rotation is reversed, and the iron core (7) of the plunger (6) moves from the non-operating position to the operating position, and the friction generating member (11) is in a non-coupling relationship with the zooming gear (2).

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, as described in detail, the rotation regulating means prevents the wobbling of the operating ring due to backlash between the zooming gear attached to the zooming operating ring and the output transmission gear of the zoom motor. Since it can be removed, it can completely eliminate problems such as the image becoming unstable every time the zoom lens barrel is carelessly hit by something or touched with the hand.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a sectional view of a zoom lens barrel, and FIG. 2 is a block diagram of a drive circuit for a zoom motor and a plunger. (1)... Operating ring, (2)... Zooming gear, (
3)...Output transmission gear, (4)...Zoom motor,
(6) Plunger, mouth □... Rotation regulating arm,
+11+...l1iI chafing member representative Mori
Yoshihiro MotoFigure 1Figure 2

Claims (1)

[Claims] 1. An operating ring for zooming, a zoom motor for driving the operating ring, a zooming gear mounted concentrically and relatively rotatably on the operating ring, and A zoom lens f7#, tube, comprising an output transmission gear that meshes with a zooming gear and transmits the output of the zoom motor to the zooming gear, and a rotation restriction means that restricts rotation of the zooming gear. 2. The zoom lens according to claim 1, wherein the rotation regulating means regulates the rotation of the zooming motor when the zoom motor is stopped, and does not restrict the rotation of the zooming gear when the zoom motor is rotating. lens barrel. 3. The zoom lens barrel according to claim 1 or 2, wherein the rotation regulating means is constituted by a friction generating member that can come into contact with the zooming gear. 4. The zoom lens barrel according to claim 5, characterized in that FeμTO is used as the rim generating member. 5. The zoom lens barrel according to claim 5, wherein a flexible synthetic resin is used as the friction generating member.