JPH0546379Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a viewfinder device for a video camera, and particularly to a lens moving mechanism.

[Summary of the idea]

The present invention is configured to move and adjust the lens held by a retaining ring in the optical axis direction within the outer casing by the feeding action of multiple guide pins by multiple helical grooves and linear grooves as the guide cylinder rotates. In a viewfinder device for a video camera, one end of a plurality of helical grooves and straight grooves is opened at one end side of a guide tube, and a retaining ring is locked with a filter ring detachably attached to an end of an outer casing. By configuring it so that it can be removed outside the outer casing,
This allows the lens to be easily attached and detached.

[Conventional technology]

Conventionally, viewfinder devices (for example, in 1983
-Refer to Publication No. 73877).

This conventional viewfinder device includes a lens assembly that is removably attached to an outer casing, and that includes a lens, a retaining ring that holds the lens, a guide tube arranged around the outer periphery of the retaining ring, and a It consists of a holding cylinder arranged on the outer periphery of the guide cylinder, a dustproof filter and an eye cap attached to the open end of the holding cylinder, and a plurality of guide pins installed on the outer periphery of the retaining ring are provided on the guide cylinder. It penetrates multiple helical grooves (both ends of these helical grooves are closed) and fits into the linear grooves of multiple guide members fixed to the inner periphery of the holding cylinder, and as the guide cylinder rotates. The lens is configured to be moved and adjusted in the optical axis direction within the outer casing by the feeding action of a plurality of guide pins by a plurality of helical grooves and linear grooves.

[The problem that the idea aims to solve]

However, with conventional viewfinder devices, when replacing or cleaning the lens, the lens assembly must be removed from the outer casing, the guide cylinder is removed from the holding cylinder of the lens assembly, and the multiple guide pins of the holding ring are removed. A disassembly process is required to remove the lens along with the retaining ring from inside the guide cylinder.
The work was extremely tedious.

SUMMARY OF THE INVENTION An object of the present invention is to provide a viewfinder device for a video camera that allows the lens to be easily removed from the inside of the outer casing.

[Means to solve the problem]

In order to achieve the above object, the viewfinder device of the present invention has one end of the plurality of helical grooves and straight grooves formed at one end of the guide tube, and a filter at the end of the outer casing. a ring is removably attached, a locking part provided on the filter ring or an auxiliary ring attached thereto is configured to be able to engage and detach from a locked part provided on the retaining ring, and the plurality of guide pins When removing the filter ring from the outer casing after moving the filter ring to the open ends of the plurality of helical grooves and straight grooves, the locking part is locked to the locked part and the filter ring is removed together with the filter ring. The retaining ring is configured to be able to be removed from the outer casing.

[Effect]

In the viewfinder device configured as described above, when the filter ring is removed from the outer casing, the lens can be easily extracted from the outer casing together with the filter ring.

〔Example〕

Hereinafter, a viewfinder device for a video camera to which the present invention is applied will be explained with reference to the drawings.

First, FIG. 6 shows the entire video camera 1, in which a lens system 3 is attached to the front end of the camera body 2, and a viewfinder device 4 is attached to the upper part of the front end of the camera body 2.

The viewfinder device 4 includes a viewfinder body 5 having a substantially rectangular parallelepiped shape attached to the camera body 2, and a viewfinder body 5 having a substantially elbow shape rotatably and removably attached to one side of the viewfinder body 5 via a rotary joint 6. an eyepiece section 7;
It has an eye cap 8 and the like attached to the rear end of the eyepiece section 7. A 1.5-inch CRT (cathode ray tube) on which images captured by the video camera 1 are displayed is housed in the viewfinder main body 5, and the CRT
A lens and a reflector for magnifying the photographed image are housed in the eyepiece section 7.

Next, details of the viewfinder device will be explained with reference to FIGS. 1A to 5.

First, the outer periphery of the lens 11 is held by a retaining ring 12, and a pair of guide pins 13 are attached to the outer periphery of the retaining ring 12 at 180° intervals. Note that small-diameter rollers 14 are rotatably attached to the outer peripheries of both guide pins 13.

Next, a pair of helical grooves 17 are provided at 180° intervals in the guide tube 16 in which the lens 11 is housed. An open end 17 in which one end of both helical grooves 17 is opened on the one end 16a side of the guide tube 16
a, and the other end is formed as a closed end 17b.

Next, the diopter adjustment ring 19 fitted to one end 16a of the guide tube 16 has a large diameter portion 19a and a small diameter portion 1.
9b are integrally molded at the front and rear. One end 16a of the guide tube 16 is provided on the inner periphery of the small diameter portion 19b.
A pair of protrusions 21 are provided at 180° intervals to fit into a pair of notches 20 provided at 180° intervals, and a female thread 22 is provided on the inner periphery of the large diameter portion 19a. A pair of recesses 19c are provided at 180° intervals on the front end surface of the large diameter portion 19a, into which a pair of knobs 23 are screwed by a plurality of screws 24 at 180° intervals. It projects outward from the diameter portion 19a. And the diopter adjustment ring 19
The inner periphery of the guide cylinder 16 is opposed to the open ends 17a of both helical grooves 17, and is connected from the small diameter part 19b to the large diameter part 1.
A pair of notches 25 cut out across 9a are 180°
are provided at intervals.

Next, a dustproof filter 28 is held in a filter ring 27 that is coupled within the large diameter portion 19a of the diopter adjustment ring 19. A male thread 29 is provided on the outer periphery of the rear end of the filter ring 27, and an annular groove 30 is provided on the inner periphery of the rear end.
An auxiliary ring 31 is locked by a plurality of locking claws 32. The auxiliary ring 31 is frictionally coupled to the filter ring 27 by a plurality of locking pawls 32, so that the auxiliary ring 31 is frictionally rotated following the rotation of the filter ring 27.

Next, the outer casing 35 of the eyepiece part 7 is short in the front cylindrical part 3.
5a, a long rear cylindrical portion 35b, and a bent portion 35c between these portions are integrally formed into a substantially elbow shape. The outer casing 35 is rotatably and detachably attached to the viewfinder main body 5 through a front cylindrical portion 35a, and the CRT 36 is disposed within the front cylindrical portion 35a. A reflecting mirror 3 is provided on the inner surface of the bent portion 35c.
7 is glued, and the lens 11 is placed inside the rear cylindrical portion 35b.
is installed as described below. Then, a pair of guide members 39 having a U-shaped cross section are bonded into a pair of grooves 38 provided on the inner periphery of the rear cylindrical portion 35b, and a pair of straight grooves 40 are formed within these pair of guide members 39. is formed. And both straight grooves 4
One end of the guide tube 16 is formed at an open end 40a that is open on the one end 16a side of the guide tube 16. A pair of slits 41 and a plurality of protrusions 42 are provided along the circumferential direction of the rear end 35d of the rear cylindrical portion 35b and are spaced apart from each other in the axial direction.

Then, the rear end surface 31a of the auxiliary ring 31 attached to the filter ring 27 and the retaining ring 1
2 are opposed to each other from the axial direction, and a pair of locking recesses 44 and locking protrusions 45 are opposed to each other at 180° between the rear end surfaces 31a and front end surfaces 12a. provided at intervals. One end side in the rotational direction of both of the locking recesses 44 and the locking convex portion 45 is formed into a locking portion 46 and a locking portion 47 formed in an inclined shape, a hook shape, or the like. .

Next, as shown in FIG. 4 and FIG.
Explain the operation of attaching.

First, both guide pins 13 of the retaining ring 12 are inserted into both helical grooves 17 of the guide cylinder 16 from the open ends 17a, and the lens 11 is rotatably accommodated in the guide cylinder 16. At this time, both guide pins 1
3 passes through both helical grooves 17 and projects outward from the guide cylinder 16.

Next, both guide pins 13 are inserted into both straight grooves 40 from the open ends 40a, and the guide cylinder 16 is inserted into the outer casing 3.
It is rotatably accommodated in the rear cylindrical portion 35b of No. 5. At this time, the other end 16b of the guide tube 16 comes into contact with an annular stepped portion 35e integrally formed on the inner periphery of the boundary between the rear cylindrical portion 35b and the bent portion 35c.

Next, insert the diopter adjustment ring 19 into the inner periphery of the rear end 35d of the rear cylindrical portion 35b, fit both protrusions 21 into both notches 20 of one end 16a of the guide tube 16, and fit both helical grooves. 17 and both notches 25 of the diopter adjustment ring 19 are connected. Then, insert both knobs 23 into both slits 41 of the rear cylindrical portion 35b from the inside, and then
3 is screwed into both notches 19c of the front end surface of the large diameter portion 19a of the diopter adjustment ring 19 with a plurality of screws 24.

Next, the male thread 29 of the filter ring 27 is screwed into the female thread 22 of the diopter adjustment ring 19 to connect them. At this time, one end 16a of the guide tube 16 is held between the inner periphery of the small diameter portion 19b of the diopter adjustment ring 19 and the outer periphery of the rear end of the auxiliary ring 31.

As described above, the diopter adjustment ring 19 and the annular stepped portion 3
5e, the movement of the guide cylinder 16 in the axial direction is restricted, and the guide cylinder 16 is integrated with the diopter adjustment ring 19.
can now rotate within the rear cylindrical portion 35b of the outer casing 35. At this time, the guide cylinder 16 can be rotated within the range of movement of the knobs 23 within the slits 41, for example, within a range of approximately 90°.

Finally, the annular attachment part 8a of the rubber eye cap 8 is fitted into the rear end 35d of the rear cylindrical part 35b of the outer casing 35, and the plurality of slits 8b of the annular attachment part 8a are inserted into the rear end of the annular attachment part 8a. Once the plurality of protrusions 42 are engaged, the series of attachment operations is completed.

According to the viewfinder device 4 configured as above, as shown in FIGS. 1A and 1B,
When the diopter adjustment ring 19 is rotated and adjusted by both knobs 23, the guide tube 16 inside the outer casing 35 is rotated together with the diopter adjustment ring 19. Then, due to the feeding action of both guide pins 13 by both helical grooves 17 and both linear grooves 40, the retaining ring 12 in the guide cylinder 16 is moved in parallel in the axial direction, and the lens 1
1 is moved and adjusted in the optical axis direction (the axial direction of the guide tube 16) between the standard viewing position shown in FIG. 1B and the maximum magnification viewing position for presbyopia shown in FIG. 1A.

Therefore, when a cameraman places his eyes on the eye cap 8 and magnifies the captured image of the video camera 1 displayed on the CRT through the reflector 37 and the lens 11, the lens 11 adjusts the diopter that suits the cameraman's presbyopia. can be adjusted by moving in the optical axis direction.

Next, when replacing the lens 11 or cleaning it by wiping off dirt, dust, etc., first remove the eye cap 8, and then rotate the diopter adjustment ring 19 to adjust the lens 11 as shown in FIGS. 1A and 1B. Move to the maximum presbyopia position shown in the figure. Then, both guide pins 13 are moved to the open ends 17a, 40a of both helical grooves 17 and both linear grooves 40, and both locking convex portions 45 of retaining ring 12 are moved to both locking concave portions of auxiliary ring 31. 44.

Next, when the filter ring 27 is rotated in the direction of arrow a in FIG. 2A in order to remove the filter ring 27 from the diopter adjustment ring 19, the auxiliary ring 31 follows the filter ring 27 and rotates in the direction of arrow a. , both locking portions 46 move in the direction of arrow a from the solid line position to the dotted line position in FIG. 2A, and both locking portions 46 are locked with both locked portions 47.

At this time, due to the screw feeding action of the male thread 29 of the filter ring 27 and the female thread 22 of the diopter adjustment ring 19, the filter ring 27 is moved as indicated by the arrow a.
While rotating in the direction, the diopter adjustment ring 19 moves in the direction of arrow b. Then, by the auxiliary ring 31 that is moved in the direction of arrow b following the filter ring 27, the retaining ring 12 is pulled out in the direction of arrow b via both the locking parts 46 and both the locked parts 47.

Therefore, as shown in FIGS. 1C and 2B, the male screw 29 of the filter ring 27 is completely removed from the female screw 22 of the diopter adjustment ring 19, and the filter ring 27 is removed from the diopter adjustment ring 19 to the outer casing 35.
When pulled out, both guide pins 1 of the retaining ring 12
3 comes out from the open ends 17a, 40a of both helical grooves 17 and both linear grooves 40 through both notches 25 of the diopter adjustment ring 19 in the direction of arrow b, and removes the retaining ring 12 and lens together with the filter ring 27. 11 can be taken out of the outer casing 35.

Therefore, the lens 11 can be easily and quickly removed from the outer casing 35, and the lens 11 can be easily replaced or cleaned.

Further, this viewfinder device 4 has an outer casing 3.
The guide tube 16 is directly rotatably supported in the rear cylindrical portion 35b of the guide tube 16.
Since the holding cylinder of a conventional lens assembly is not interposed between the lens assembly and the outer housing 35, the outer diameter of the outer housing 35 is small and the weight is also reduced.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments, and various effective changes can be made based on the technical idea of the present invention.

For example, in the embodiment, the male thread 29 of the filter ring 27 is configured to be screwed into the female thread 22 of the diopter adjustment ring 19, but the filter ring 27
It is possible to change the structure so that 7 is fitted to the rear end 35d of the outer casing 35 and fixed with a screw. In this case, the auxiliary ring 31 is not used and the locking part provided on the filter ring can be locked to a locked portion provided on the retaining ring 12, and the retaining ring can be pulled out of the outer casing.

[Effect of idea]

Since the present invention is configured as described above,
This produces the following effects.

Since the lens of the viewfinder device can be easily removed from the outer casing together with the filter ring, lens replacement and cleaning operations can be performed easily and quickly.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIGS. 1A to 1C are partially cutaway perspective views showing the main parts, and FIGS. 2A and 2B are perspective views showing the main parts. 3 is an exploded perspective view of the entire viewfinder device, FIG. 4 is a central longitudinal cross-sectional view of the entire viewfinder device, and FIG. 5 is a cross-sectional view of the entire viewfinder device.
A sectional view taken in the direction of arrows, and FIG. 6 is a perspective view of the entire video camera. In addition, in the symbols used in the drawings, 1
... video camera, 4 ... viewfinder device, 11 ... lens, 12 ... retaining ring, 13
...Guide pin, 16...Guide cylinder, 16a...
One end of the guide tube, 17... Spiral groove, 17a...
Open end of helical groove, 27...filter ring,
31... Auxiliary ring, 35... Outer casing, 40... Straight groove, 40a... Open end of the straight groove, 46... Locking portion, 47... Locked portion.

Claims (1)

[Claim for Utility Model Registration] A retaining ring that holds the lens is provided with a lens for magnifying an image captured by a video camera, and is disposed within a rotatable guide cylinder within an outer casing, and the outer periphery of the retaining ring is A plurality of guide pins provided on the guide tube pass through a plurality of helical grooves provided on the guide tube and fit into a plurality of linear grooves fixedly provided outside the guide tube, and as the guide tube rotates. In the view finder device for a video camera configured to move and adjust the lens in the optical axis direction within the outer casing by the feeding action of the plurality of guide pins by the plurality of helical grooves and linear grooves, one end of the plurality of helical grooves and linear grooves are formed as an open end, and a filter ring is removably attached to the end of the outer casing, and the filter ring or an auxiliary ring attached thereto; The locking part provided on the retaining ring is configured to be able to engage with and detach from the locked part provided on the retaining ring, and after moving the plurality of guide pins to the open ends of the plurality of helical grooves and linear grooves, When the filter ring is removed from the outer casing, the locking portion is locked to the locked portion so that the retaining ring can be pulled out of the outer casing together with the filter ring. Features: Video camera viewfinder device.