JPS5964804A - Lens barrel - Google Patents

Abstract

PURPOSE:To reduce the number of parts and the cost and to simplify assembling by forming a regulating part, which regulates the movement of a driving ring, and a pressing part, which presses the ring in the radial direction, in a turning barrel as one body. CONSTITUTION:A fixed pawl 2b which regulates the movement of a zoom gear 10 as the driving ring and a pressing pawl 2c which presses the gear 10 in the radial direction are formed with a resin together with a turning barrel 2 as one body and can be deformed elastically in directions of arrows B and B' and arrows C and C' respectively. The gear 10 is inserted and set easily from the right of the barrel 2, and its movement in the axial direction is regulated by the pawl 2b. In this state, the pawl 2c presses the gear 10 from the inside to generate a frictional force between the gear 10 and the pawl 2c, and the rotatory force of the gear 10 is transmitted to the barrel 2. Therefore, parts which are provided independently of the barrel conventionally are formed together with the barrel as one body, and the number of parts and the cost are reduced to simplify assembling.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a lens barrel used in a video camera or the like, and particularly to a rotating lens barrel for focusing and zooming.

Conventional configurations and their problems In recent years, the market for portable video tape recorders has grown in size due to the spread of portable video tape recorders. In order to improve its usability, the focus lens and zoom lens are driven by a motor.

So-called autofocus mechanisms and power zoom mechanisms have come into use. In the case of autofocus, the focal length is detected and the focusing ring is moved back and forth.The general mechanism for this operation is to connect a coaxial rotatable gear ring to the focusing ring and a driving device. This method uses the frictional force generated at that time between the gear ring and the focusing ring to move the lens group. In this case, the focus ring and gear ring are constructed so that they slip when a certain load is applied.

On the other hand, zooming is performed by a movable lens group that is movable in the optical axis direction by rotating a rotating lens barrel. Generally, a zoom motor rotates a drive ring that is attached coaxially to the rotating lens barrel so that it can rotate once, thereby rotating the driving ring and rotating lens barrel.When a certain load is applied, the driving ring and rotating lens barrel rotate. This causes slip to occur between the two.

3.,-FIG. 1 shows, as an example, a conventional lens barrel using a power zoom mechanism. In the figure, a rotary lens barrel 2 for operating a zoom lens L is attached to the outside of a fixed lens barrel 1 so as to be rotatable with respect to the fixed lens barrel 1. A cam pinch implanted in a zoom lens moving frame to which the zoom lens L is fixed is slidably engaged with a cam groove 6 provided in a cam barrel 5. Furthermore, a fixing member 2a is provided on the rotary lens barrel 2 so that a fixing pin 7 implanted in the cam barrel 6 can be moved integrally therewith.

This fixed member 2a is free from movement of the rotating lens barrel 2 in the axial direction. With such a configuration, by rotating the rotating lens barrel 2, the zoom lens L can be moved in the optical axis direction.

A zoom motor 8 used as a zoom drive source is attached to a motor fixing base 9, and a zoom gear 10 mounted coaxially with the rotating lens barrel 2 and a motor gear 11 fixed to the zoom motor 8 are arranged so that they come into contact near the pitch circle. It has become. In order to transmit the rotational force of the zoom gear 10 to the rotating lens barrel 2, it is pressed by a spring member 12, and a zoom gear stopper 13 is also provided at the same time to prevent the zoom gear 10 from moving in the optical axis direction due to this suppressing means. There is. zoom gear 9
When a certain load is applied to the spring material 12, a slip force is generated between the lens barrel 12 and the rotation of the zoom motor 8, even if the rotating lens barrel 2 is stopped due to rotation angle regulation. On the other hand, the rotary lens barrel 2 can be rotated even if the zoom motor 8 does not rotate. Although the above example shows a power zoom drive mechanism, the drive mechanism used for autofocus can be considered to be almost the same.

In this way, in the case of power zoom and autofocus, a friction member is required between the rotating lens barrel and the ring that coaxially transmits the drive means to the rotating lens barrel, and the ring and the friction member are also required. A fixing member is required to fix it. Therefore, when an autofocus mechanism or a power zoom mechanism is used, the lens barrel has many parts, is expensive, and is difficult to assemble.

OBJECTS OF THE INVENTION The present invention aims to solve the above-mentioned problems of the prior art, and provides a lens that reduces the number of parts of the drive transmission means, reduces costs, and can be assembled extremely easily. It provides a lens barrel.

Structure of the Invention The present invention provides a fixed lens barrel, a rotating lens barrel that moves a lens in the optical axis direction by rotation, and a drive ring coaxially and rotatably attached to the rotating lens barrel. The rotating mirror includes a driving means for driving the driving ring, and a regulating member for regulating the movement of the driving ring in the optical axis direction and a pressing member for elastically pressing the driving ring in the radial direction. It is formed integrally with the cylinder.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIGS. 2(a) and 2(b) are a top view and a cross-sectional view taken along the line A-A' of an embodiment of the present invention, which show the rotary lens barrel 2 in FIG. The part that connects to the zoom gear 10 attached to the camera is shown.

Further, FIG. 3 shows a perspective view of the main parts of the rotating lens barrel.

In those drawings, the fixing claw 2b6/
＼-shi and the pressing claw 2C, which is a suppressing member, are made of resin integrally with the rotating lens barrel 2, and are indicated by arrows B, B', and C.

It has a shape that can be elastically deformed in the direction of C'. In FIG. 2, the zoom gear 10 is attached from the right side of the rotating lens barrel 2, but when it is attached, the fixed claw 2b is deformed in the direction of arrow B' to enable attachment, and after attachment, the fixed claw 2b may be By entering the state, movement of the zoom gear 1o in the optical axis direction is restricted.

In addition, the pressing claw 2C can be moved to arrow C by attaching the zoom gear 1o.
' Receives elastic deformation in the force direction and constantly presses the inside of the zoom gear 10 in the radial direction. Therefore, since a frictional force is always generated between the pressing claw 2C and the zoom gear 10, the rotational force of the zoom gear can be transmitted to the rotating lens barrel 2 by this force. It goes without saying that by providing this member at several locations on the rotary lens barrel 2, the movement in the optical axis direction by the υ fixing claw 2b is regulated and the frictional force due to elastic deformation by the pressing claw 2C is stabilized. Additionally, if a certain load is applied to the rotating lens barrel while the zoom motor 8 (see Figure 1) is in operation, a slipping force will occur, similar to when using conventional springs 7--. It is.

Effects of the Invention As described above, the present invention provides a rotating lens barrel with a regulating member (corresponding to the above-mentioned fixed claw 2b) and a pressing member (corresponding to the pressing claw 2C) in an integrated manner. Since special members can be omitted, this has great effects in terms of ease of assembly, cost, number of parts, etc.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a conventional example equipped with a power zoom mechanism, FIGS. 2(a) and (b) are a top view and a sectional view of a main part of an embodiment of the present invention, and FIG. 3 is a main part of the same. FIG. 1...Fixed lens barrel, 2...Rotating lens barrel, 2
b... Fixed claw, 2C... Pressing claw, 4.
...Cam pin, 5...Cam tube, 6...
...Cam groove, 7...Fixed pin, 8...
・Zoom motor, 1o...Zoom gear, L・
...Zoom lens. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 15

Claims (1)

[Claims] A fixed lens barrel, a rotating lens barrel that rotates to move the lens in the optical axis direction, a drive ring coaxially and rotatably attached to the rotating lens barrel, and a drive that drives the drive ring. A regulating member for regulating the movement of the drive ring in the optical axis direction and a suppressing member for elastically pressing the drive ring in the radial direction are integrally formed on the rotating lens barrel. A lens barrel characterized by: