JPH06100703B2 - Lens moving device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens moving device effective for use in a video camera or the like.

2. Description of the Related Art In recent years, video cameras and the like are required to have an autofocus function for automatically focusing.

A conventional lens moving device will be described with reference to FIG. FIG. 4 is a sectional view of the main part of the lens barrel, in which the cam frame 3 is rotatably supported inside the lens barrel body 1, and
Both ends are supported by the lens barrel body 1 and the front frame 4 attached to the lens barrel body 1, and movement in the optical axis direction is restricted with a predetermined gap. The variable-magnification lens frame 2 holds the variable-magnification lens L3 by adhesion or the like, and is guided in the optical axis direction by being guided by a guide pole 5 supported by fitting one end into the lens barrel body 1 and the other end into the front frame 4. Moving. The front frame 4 has a female helicoid screw 8 that is screwed into the male helicoid screw 7 of the focus helicoid 6 on the inner circumference of the front portion, and a protrusion 12 that limits the rotation of the focus ring 9 to a predetermined angle on the outer circumference.
The focus helicoid 6 holds the focusing lens groups L1 and L2, and has a male helicoid screw 7 that is screwed into the female helicoid screw 8 of the front frame 4, and is rotated around the optical axis to move in the optical axis direction. Move to and adjust the focus. The focus ring 9 is fitted with the focus helicoid 6 and is attached by the attachment screw 11.
It rotates around the optical axis integrally with the above, and is regulated to a predetermined rotation angle by the projection 12 provided on the outer periphery of the front frame 4.

The distance between the focusing lens units L1 and L2 and the zoom lens L3 is
It is necessary to make adjustments after assembling the lens unit in order to absorb variations due to lens processing accuracy and assembly errors. By adjusting the phases of the focus ring 9 and the focus helicoid 6, the focusing lens groups L1 and L2 and variable magnification are adjusted. Lens L
It is configured to adjust the interval of 3 and then tighten the mounting screw 11.

Further, a rubber ring 13 is wound around the outer circumference of the focus ring 9 so that the mounting screw 11 does not appear in the appearance. The zoom ring 14 is rotatably mounted on the outer periphery of the lens barrel body 1 and rotates a predetermined angle.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-described conventional configuration, since the mounting screw 11 is used to fix the focus helicoid 6 and the focus ring 9, the tightening force of the mounting screw 11 causes the focus helicoid to be fixed. A strong force acts on 6 to deform the male helicoid screw 7 of the focus helicoid 6, and the engagement between the male helicoid screw 7 and the female helicoid screw 8 of the front frame 4 becomes poor, so that the focus helicoid 6 rotates smoothly. There was a problem of disappearing. Also, when re-adjusting, it was difficult to make fine adjustment due to the original screw after re-fastening the screw.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and an object of the present invention is to provide a lens moving device that improves the workability of adjustment and ensures the autofocus function of a video camera or the like.

Means for Solving the Problems In order to solve the above problems, a lens moving device according to the present invention has a lens holding ring that holds a lens and has a first helicoid screw, and a lens holding ring that projects to the outer peripheral portion of the lens holding ring. An operating ring provided with a protruding portion provided and a restricting portion that has an inserting portion into which the protruding portion can be inserted and engages slidably by being inserted and then rotated to regulate the position in the optical axis direction; ,
An opening hole provided in the operation ring, through which the protrusion can be exposed, and an adhesive tape-like member for connecting the tip end portion of the protrusion exposed from the opening hole and the operation ring at a predetermined adjustment position. And a fixing ring having a second helicoid screw screwed into the first helicoid screw and having a regulating means for regulating the rotation range of the operation ring. Be prepared.

Action With the above configuration, the lens retainer ring is prevented from coming off while it is easy to assemble, and the protrusions on the lens holding ring are directly exposed through the opening holes in the operation ring. (Adjustment), the position of the protrusion can be adjusted through the opening hole, improving the workability of the adjustment, and the protrusion and the position regulating part of the operating ring are in sliding contact, so the resolution of adjustment is high and the focus adjustment is easy. The effect is that fine adjustment can be easily performed and it can be securely fixed even after adjustment.

Embodiment A lens moving device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the main part of an embodiment of the present invention. It should be noted that, in order to explain the operation, the portion below the dashed-dotted line in the center of the figure is shown with the lens shifted in the optical axis direction.

In FIG. 1, the cam frame 21 is rotatably supported inside the main body 22, and the flange portion 21a of the cam frame 21 is sandwiched between the main body 22 and the front frame 23 (fixing ring) so that the position in the optical axis 24 direction Is regulated. The variable magnification lens frame 25 has variable magnification lenses L4 and L5.
Is held, and one end is guided by a guide pole 26 which is supported by fitting the other end into the main body 22 and the other end into the front frame 23, and the pin 27 planted in the variable magnification lens frame 25 has a cam groove of the cam frame 21. It is driven by 21b and moved in the direction of the optical axis 24.

The front frame 23 has a female helicoid screw 30 that is screwed into a male helicoid screw 29 of a focus helicoid 28 (lens holding ring) on the inner circumference of the front part, and rotates the focus ring 31 (operating ring) at a predetermined angle on the outer circumference. A stopper 32 for regulating is provided. A rubber 32b is wound around the stopper 32 to reduce the noise when the protruding portion 31b of the focus ring 31 is brought into contact with the rotation end to be regulated.

The focus helicoid 28 holds the focusing lens units L1, L2, L3 by crimping and a clip spring 33, and has a plurality of protrusions 34 on the outer circumference fitted with the inner circumference 31a of the focus ring 31.
(Projection). The focus ring 31 positioned by the rear end surface 34a of the projection 34 and the front end surface 28a of the focus helicoid 28 in the optical axis 24 direction corresponds to the number of the projections 34 as shown in the plan view of the main part of FIG. It has a plurality of opening holes 35, and the projection 34 can be exposed from the opening holes 35. A notch 36 having a width l _{2 that} is larger than the width l _{1 of the} protrusion 34 is provided at the end of the opening hole 35.The protrusion 34 of the focus helicoid 28 is inserted into the notch 36, and is moved in the direction of arrow 37. By rotating, the stopper 34 is prevented from coming off in the direction of the optical axis 24, and the projection 34 is engaged with the opening hole 35 so as to be slidable.

FIG. 3 is a perspective view of an essential part showing a portion of the opening hole 35, and the focus ring 31 is a wall 3 that can be slidably contacted with the rear end surface 34a of the protrusion 34.
Have eight. As shown in FIG. 1, the focus ring 31 integrally has a lens hood portion 39 at the tip, and by rotating this portion, a manual focus operation is performed, and the gear portion 40 at the rear end of the focus ring 31 is moved. The autofocus operation is performed by driving the motor 41.

The adhesive film tape 42 (coupling means) is wound around the tip portion of the projection 34 of the focus helicoid 28 and the focus ring 31, and the focus helicoid 28
And the focus ring 31 are integrally connected. The cover ring 43 is wound on the film tape 42 so that the film tape 42 does not appear in the appearance. The zoom ring 44 is
It is guided by the front frame 23 and the main body 22 and is rotatably attached. It rotates by a predetermined angle and drives the cam frame 21 to move the magnification changing lenses L4 and L5 in the direction of the optical axis 24 to perform the magnification changing operation. Is configured to do.

The operation of the lens moving device configured as described above will be described below.

Focus helicoid holding focusing lens groups L1, L2, L3
The male helicoid screw 28 of 28 is screwed into the female helicoid screw 28 of the front frame 23, and the protrusion 34 of the focus helicoid 28 is inserted into the cutout portion 36 of the focus ring 31.
Assemble 31. Next, the protrusion 31 of the focus ring 31
While b is in contact with the stopper 32, the projection 34 is driven through the opening hole 35 to move only the focus helicoid 28 to the optical axis 24.
Rotate around and move the focusing lens groups L1, L2, L3 in the direction of the optical axis 24 according to the screw lead of the helicoid, and adjust the position of the focusing lens groups L1, L2, L3 using a collimator etc. Adjust the focus. After the adjustment, the film tape 42 is wound around the protrusion 34 of the focus helicoid 28 to fix the focus ring 31 integrally with the focus helicoid 28.

As described above, after the projection 34 of the focus helicoid 28 and the opening hole 35 of the focus ring 31 are slidably engaged with each other,
Since the focus helicoid 28 and the focus ring 31 are fixed by using the film tape 42, a strong force does not act on the helicoid screw portion, deformation of the helicoid screw portion can be prevented, and smooth rotation can be maintained. Further, fine adjustment at the time of readjustment can be easily performed.

EFFECTS OF THE INVENTION As described above, the lens holding ring that holds the lens and has the first helicoid screw, the protrusion that protrudes from the outer peripheral portion of the lens holding ring, and the insertion portion into which the protrusion can be inserted are provided. An operating ring provided with a restricting portion that engages slidably by rotating after being inserted, and restricts the position in the optical axis direction; and an opening hole in which the projecting portion is exposed in the operating ring, An adhesive tape-like body for connecting the tip end portion of the protrusion exposed from the opening hole and the operation ring at a predetermined adjustment position, and a second helicoid screw screwed into the first helicoid screw. And a fixing ring provided with a restricting means for restricting the rotation range of the operation ring to prevent disengagement in the direction of the optical axis and also has good assemblability. Operation Since it is directly exposed from the opening hole of the lens, the position of the protrusion can be adjusted through the opening during adjustment (focus adjustment) when assembling the lens unit, improving the workability of adjustment and operating the protrusion. Since the position control part of the ring is in sliding contact, the resolution of adjustment is high and fine adjustment of focus adjustment can be easily performed, and it is possible to securely fix even after adjustment, the number of parts is small and the assembly and adjustment are easy. It has a great practical effect such as being able to be performed.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a lens moving device according to an embodiment of the present invention, FIG. 2 is a plan view of an essential part of the device, FIG. 3 is a perspective view of an essential part of the device, and FIG. It is a principal part sectional view of a lens moving device. 23 …… front frame, 28 …… focus helicoid, 31 …… focus ring, 32 …… stopper, 34 …… protrusion, 35 ……
Opening hole, 42 ... film tape.

Claims (1)

[Claims] 1. A lens holding ring for holding a lens and having a first helicoid screw, a protrusion protruding from an outer peripheral portion of the lens holding ring, and an insertion portion into which the protrusion can be inserted. After that, the operation ring is provided with a restriction portion that engages in a slidable manner by sliding and then regulates the position in the optical axis direction, an opening hole provided in the operation ring, through which the protrusion can be exposed, and the opening. A tape-like body having adhesiveness for connecting the tip end portion of the protrusion exposed from the hole and the operation ring at a predetermined adjustment position, and a second helicoid screw screwed into the first helicoid screw are provided. A lens moving device, comprising: a fixing ring provided with a restricting means for restricting a rotation range of the operation ring.