JPH0620260B2 - Lens tracking lock device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a lens barrel with adjustable tracking.

<Prior Art and its Problems> FIGS. 8 and 9 show a video camera having a lens barrel capable of adjusting lens tracking according to a conventional example. That is, a fixed structure member 2 of a video camera having a zoom lens barrel 1 including a photographing optical system is provided with a lens holding barrel 4 holding a tracking adjustment lens 3 on its optical axis and a known imaging device 5. The lens holding cylinder 4
Has a notch groove 4a in the circumferential direction formed on the outer periphery thereof. Further, a lock screw 6 for fixing the lens holding cylinder 4 is screwed into the structural member 2, and the notch groove 4a of the lens holding cylinder 4 is screwed. An insertion hole 2a for engaging the tracking adjustment tool 7 is provided in the. At the time of this tracking adjustment, the locking screw 6 is loosened to insert the tracking adjustment tool 7 into the insertion hole 2a.
eccentric pin 7a is inserted into the notch groove 4a of the lens holding barrel 4 and the tracking adjusting tool 7 is rotated to move the lens holding barrel 4 forward and backward in the optical axis direction for tracking adjustment. It is connected. In this case, the lens holding barrel 4 moves back and forth on a one-to-one basis with the eccentricity of the tracking adjustment tool 7, so the structure is unsuitable for minute adjustments.

After adjusting the tracking, tighten the lock screw 6
When trying to fix the lens holding cylinder 4, when the lock screw 6 is temporarily fixed or when the lock screw 6 is tightened at a position near the dented scratch on the outer periphery of the lens holding cylinder 4 attached by the uneven surface of the tip at the time of the previous fixing. However, the lock screw 6 fell into the dent again, and even if fine adjustment was performed, the lens holding cylinder 4 moved to the original position, and fine adjustment was impossible.

<Objects of the Invention> The present invention eliminates the above-mentioned drawbacks of the prior art, facilitates fine adjustment of the tracking adjustment of the lens, and also makes it possible to smoothly perform locking after fine adjustment during readjustment. The object is to provide a kinglock device.

<Structure of the Invention> The present invention provides a fixed structural member, a lens holding cylinder that holds a lens that moves forward and backward in the optical axis direction to perform a tracking action in the fixed structural member, and has a notch groove on the outer periphery thereof, and one end A protruding portion with which the cutout groove engages in the central portion and a tracking adjustment plate having an arcuate hole at the other end in the center, and the fixing structural member through the arcuate hole with respect to the fixed structural member. A locking screw for fixing the tracking adjustment plate, and the position of the lens holding cylinder is adjusted by adjusting the tracking adjustment plate.

<Description of Embodiments> Embodiments of the present invention will be described with reference to the drawings.

1 to 3 show a first embodiment of a lens tracking lock device according to the present invention used in a video camera.
FIG. 2 is a side view of the main part, FIG. 2 is a cross-sectional view taken along the line I--I of FIG. 1, and FIG.

In the figure, 11 is a zoom lens barrel including a photographing optical system,
Reference numeral 2 denotes a fixed structural member of the video camera, which is provided with a lens holding barrel 14 holding a tracking adjusting lens 13 on the optical axis thereof and an image pickup device (not shown). And the engaging recess 12b of the eccentric pin 17a of the tracking adjusting tool 17. A circumferential notch groove 14a is formed on the outer circumference of the lens holding cylinder 14. Reference numeral 18 denotes a tracking adjusting plate, one end of which is rotatably supported at the lower part of the opening 12a of the structural member 12 by a step screw 19, and the notch groove 14a of the lens holding cylinder 14 is engaged with the center thereof. The tracking adjustment plate is provided with a locking screw 16 having a projection 18a and an arc-shaped hole 18b having the step screw 19 as the center of rotation at the other end, and screwed into the structural member 12 through the arc-shaped hole 18b. 18 is fixed, and a tracking adjusting tool insertion hole 18c for engaging the eccentric pin 17a of the tracking adjusting tool 17 with the engaging recess 12b of the structural member 12 is provided.

Next, the operation of this embodiment having the above configuration will be described.

First, in the state shown in FIGS. 1 and 2, the locking screw 16 is loosened, the tracking adjustment tool 17 is inserted into the insertion hole 18c of the tracking adjustment plate 18, and the eccentric pin 17a thereof is inserted.
Is engaged with the engaging recess 12b of the structural member 12.

Then, when the tracking adjusting tool 17 is rotated, the tracking adjusting plate 18 is rotated about the eccentric amount about the step screw 19 as a fulcrum, and the protrusion 18a thereof causes the lens holding cylinder 14 to rotate.
Is moved in the direction of the optical axis, and the state shown in FIG. 3 is obtained. At this time, the step screw 1 which is the fulcrum of rotation of the tracking adjustment plate 18
9 and the protrusion that engages with the notch groove 14a of the lens holding cylinder 14.
Since the positional relationship between 18a and the tracking adjusting tool 17 is a lever relationship, the movement of the lens holding barrel 14 in the optical axis direction becomes smaller than the eccentric amount of the tracking adjusting tool 17, so that the tracking can be finely adjusted. it can.
After the required adjustment is completed in the state shown in FIG. 3, lock screw 1
By tightening 6, the tracking adjusting plate 18 presses the lens holding cylinder 14 and is fixed. In this case, since the outer circumference of the lens holding cylinder 14 is not scratched or the like, the lens holding or the like is not returned to the original position unlike the conventional case even if the fine adjustment is performed.

4 and 5 show a second embodiment of the present invention in which a gear type tracking adjusting tool is used. The same parts as those of the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted. Only will be described.

The tracking adjustment plate 18 has a lens holding cylinder 14 at the center.
Is provided with a protruding portion 18a that engages with the notch groove 14a of the gear, and a gear portion 18d is formed at the edge of the arcuate hole 18b side. It has an engaging recess 12b with which the'a is engaged. When the pin 17'a of the tracking adjusting tool 17 'is engaged with the engaging recess 12b of the structural member 12, the gear portion 17'b provided at the tip end of the pin 17'a and the gear portion 18d of the tracking adjusting plate 18 are It has come to mesh. Also, the step screw 19
A lead wire lug plate 20 is attached to the.

Therefore, when adjusting the tracking of the lens, loosen the lock screw 16 and use the pin of the tracking adjustment tool 17 '.
17'a is engaged with the engaging recess 12b of the structural member 12 and its gear portion 17'b is meshed with the gear portion 18d of the tracking adjusting plate 18. Next, when the tracking adjusting tool 17 'is rotated, the tracking adjusting plate 18 rotates about the step screw 19 as a fulcrum, and the projection 18a thereof causes the lens holding cylinder 14 to rotate.
Is moved in the optical axis direction, and tracking adjustment is performed in the same manner as in the above-described embodiment. After the adjustment is completed, the locking screw 16 is tightened so that the tracking adjustment plate 18 is moved to the lens holding cylinder 14.
Press to fix.

6 and 7 show a third embodiment of the present invention in which the lens holding cylinder is largely moved with respect to the rotation of the tracking adjustment tool. Explaining only the same difference, the tracking adjustment plate 18 has a center portion. A protrusion 18a that engages with the cutout groove 14a of the lens holding cylinder 14 is provided in the portion, and is supported rotatably by a step screw 19 near the center and one end of the tracking adjustment tool 17 with an eccentric pin 17a. The tracking adjusting plate is provided with an insertion hole 18c, an arc-shaped hole 18b having the step screw 19 as a rotation center at the other end, and a locking screw 16 screwed into the structural member 12 through the arc-shaped hole 18b. 18 is fixed.

Therefore, when the tracking adjustment of the lens is performed, the locking screw 16 is loosened, the tracking adjustment tool 17 is inserted into the insertion hole 18c of the tracking adjustment plate 18, and the eccentric pin
When it is rotated about 17a, the tracking adjustment plate 18 is moved by the amount of eccentricity, as in the first embodiment described above.
The lens holding cylinder 14 is moved in the optical axis direction with the fulcrum 9 as the fulcrum. Due to the positions of being symmetrical with respect to each other, the tracking adjustment is performed by making the movement of the lens holding cylinder 14 larger than that of the first embodiment described above as compared with the eccentric amount of the tracking adjustment tool 17.

In addition, when the engagement shape of the protrusion of the tracking adjustment plate that engages with the notch groove of the lens holding cylinder in each of the above-described embodiments is a tapered protrusion, the notch groove of the lens holding cylinder and the protrusion of the tracking adjustment plate. Since there is no rattling with the portion, it is possible to prevent movement due to rattling during tracking adjustment or impact after rocking, which is preferable.

<Advantages of the Invention> As described above, according to the present invention, a tracking adjustment plate that engages with a lens holding cylinder that performs a tracking operation is rotatably attached to the lens holding cylinder by using a conventionally used tracking adjustment tool. The cylinder can be finely adjusted, and the lens holding cylinder can be locked without being scratched.

[Brief description of drawings]

1 to 3 show a first embodiment of a lens tracking lock device according to the present invention, and FIG. 1 is a side view of its essential parts,
2 is a sectional view taken along the line I--I of FIG. 1, FIG. 3 is a side view of a main portion at the time of tracking adjustment, FIGS. 4 and 5 are a second embodiment of the present invention, and FIG. FIG. 5 is a side view of an essential part, FIG. 5 is a sectional view taken along the line I--I of FIG. 4, FIGS. 6 and 7 are a third embodiment of the present invention, and FIG. Is a cross-sectional view taken along the line I-I, FIGS. 8 and 9 are lens tracking lock devices in a conventional video camera, FIG. 8 is a schematic cross-sectional view thereof, and FIG. 9 is a line II-II of FIG. FIG. 11 ... Zoom system lens barrel including photographing optical system, 12 ... Fixed structural member of video camera, 13 ... Tracking adjustment lens, 14 ... Lens holding cylinder, 14a ... Notch groove, 1
6, 16 '... Lock screw, 17, 17' ... Tracking adjustment tool, 18 ... Tracking adjustment plate, 18a.
Projection, 18b ... Arc-shaped hole, 18c ... Insertion hole, 18d ... Gear part, 19 ... Step screw.

Claims (1)

[Claims] 1. A fixed structural member, a lens holding cylinder for holding a lens that moves forward and backward in the optical axis direction to perform a tracking action in the fixed structural member, and has a notch groove on its outer periphery, one end of which is relative to the fixed structural member. A protrusion that is axially supported and that engages with the cutout groove in the center, a tracking adjustment plate that has an arcuate hole at the other end, and for fixing the tracking adjustment plate to the fixed structural member through the arcuate hole. The lens tracking lock device is characterized in that the position of the lens holding cylinder is adjusted by adjusting the tracking adjustment plate.