JPH06303496A - Lens cover driving mechanism - Google Patents

Abstract

PURPOSE:To obtain a lens cover driving mechanism to allow the opening and closing of a lens cover to operate as linked with the movement of the zoom lens of a lens optical system in a camcorder. CONSTITUTION:A disk cam 16 is driven to rotate by making a zoom driving motor 8 a driving source, and the lens cover 11 is made to operate to open and close through a first link 20 to be operated with a fulcrum shaft 22 as a fulcrum by a first cam groove 19 formed on the disk cam 16, and besides, a wide conversion lens 13 is operated and switched through a second link 31 to be moved up and down by a cam surface 30 formed on the disk cam 16, and further, the zoom lens 26 is made to operate in zoom by a second cam groove 25 formed on the disk cam 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens cover drive mechanism suitable for use in a camera-integrated VTR.

[0002]

2. Description of the Related Art Conventionally, a camera-integrated VTR of this type is provided with a lens cover for protecting the front surface of a lens forming a lens optical system, that is, the front surface of a front lens. As a general lens cover, the front surface of the front lens is protected by a cap-type lens cover. Recently, there is a lens cover that is built into the cabinet and that can open and close the front surface of the front lens.

[0003]

The opening / closing of the built-in lens cover as described above is performed by an opening / closing mechanism unique to the lens cover in addition to the lens optical system.

That is, the lens optical system of the camera-integrated VTR is composed of only a lens group, and does not include a mechanism including a lens cover. Therefore, the lens cover is regarded as an external accessory, and is not considered as a part of the operation of the lens optical system like the still camera, but is considered separately from the lens optical system.

The present invention has been made in order to solve the above-mentioned problems, and a lens cover drive mechanism for opening and closing the lens cover in association with the movement of the zoom lens of the lens optical system. Aim to get.

[0006]

In order to achieve the above object, in the lens cover drive mechanism according to the present invention, the zoom lens drive means performs the zooming operation of the zoom lens via the operation transmission mechanism, and the movement of the zoom lens is performed. The lens cover is opened and closed through a motion transmission mechanism in conjunction with the.

[0007]

In the lens cover drive mechanism of the present invention constructed as described above, when the zoom lens driving means performs the zooming operation of the zoom lens via the operation transmission mechanism, the operation mechanism transmits the movement of the zoom lens. The lens cover can be opened and closed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A lens cover driving mechanism according to an embodiment of the present invention will be described below with reference to the accompanying drawings by taking an example in which it is applied to a camera-integrated VTR.

FIG. 1 is a perspective view of a camera-integrated VTR having a lens cover drive mechanism of this embodiment, FIG. 2 is a perspective view of an optical mechanism section and a lens cover drive mechanism, and FIG. 3 is a front view of the lens cover drive mechanism. FIG. 4 is also a plan view of the lens cover drive mechanism.

In FIG. 1, a camera-integrated VTR is indicated by reference numeral 1 as a whole. The main structure of the camera-integrated VTR 1 will be described. An optical mechanism unit 3 including a photographing lens is provided on the front end side of the upper portion of the main body 2 shown by reference numeral 2, and a viewfinder 4 is provided on the rear side of the upper portion. Reference numeral 5 is an operation switch for switching the optical mechanism section 3 between wide angle (wide) and telephoto (tele). A recording / playback mechanism (not shown) is housed in the main body 2. 6 is a microphone as a sound collecting unit.

2 to 4, the optical mechanism section 3 constitutes a photographing lens group (not shown) in the lens barrel 7, the rear of the optical mechanism section 3 is provided with a CCD image pickup device 3a, and the photographing lens is used. A zoom drive motor 8 as a zoom lens drive means for performing a zooming operation of a zoom lens described later of the group, a drive motor 9 for focus adjustment, and an iris meter 10 are provided.

A lens cover 11 for opening and closing the front surface of the lens barrel 7, that is, the front surface of the front lens of the taking lens group.
Are arranged. The lens cover 11 is attached so as to be vertically movable along a guide groove 12a of a lens opening 12 formed in the front panel P. Further, in front of the front lens, behind the lens cover 11, there is arranged a wide (wide-angle) conversion lens 13 which can be put in and out of the front lens.

The drive mechanism of the lens cover 11 will be described below. A disc cam 16 as a drive transmission mechanism having a tooth portion 15 on the outer periphery is rotatably supported around a shaft 14 supported on a side portion of the lens barrel 7. The disc cam 16 is provided by the zoom drive motor 8 and the speed reduction mechanism 17 described above.
The output gear 18 provided through the gear meshes with the tooth portion 15 and is rotationally driven.

The first cam groove 1 is formed on the outer surface of the disc cam 16.
9 is formed. The first cam groove 19 has a shape that reaches the outer peripheral portion of the disc cam 16 after making a half turn around the shaft 14. The cam groove 19 and the lens cover 11 are connected by a first link 20. That is, the first link 20 has the long hole 21 formed in the middle portion thereof.
Is supported on the fulcrum shaft 22 supported on the lens barrel 7 via
A pin 23 protruding from one end side of the first link 20 is engaged with the cam groove 19, and the other end side of the first link 20 is supported by a pin 24 protruding from a side portion of the lens cover 11. .

On the other hand, a second cam groove 25 is formed on the back surface of the disc cam 11. The shape of the second cam groove 25 extends from the vicinity of the shaft 14 to reach the outer peripheral portion of the disc cam 16 in an arc shape, and then is formed on the outer peripheral portion of the disc cam 16 over a substantially half circumference. A lens holder 27 of a zoom lens (variator lens) 26 in the lens barrel 7 is provided in the cam groove 25.
The tip end of a pin 29 projecting through a horizontal guide hole 28 formed in the lens barrel 7 is engaged.

A cam surface 30 is formed on the back surface of the disc cam 16 described above. The cam surface 30 is in contact with the middle of a second link 31 having a substantially V shape, and the rear end of the second link 31 is supported by a fulcrum pin 32 protruding from the lens barrel 7, Of the link 3 of the pin 3 protruding from the wide conversion lens 13 described above.
It is supported by 3. The tip end side of the second link 31 is biased by the spring 34 toward the open side of the wide conversion lens 13.

The above-mentioned driving of the lens cover 11 and the wide conversion lens 13 is performed in conjunction with the rotation operation of the disc cam 16 which performs the zooming operation of the zoom lens 26. Hereinafter, the lens cover 11 and the wide conversion lens 13 will be described. A series of operations of the zoom lens 26 will be described with reference to FIGS.

Opening / Closing Operation of Lens Cover FIG. 5a is a non-photographing state in which the lens cover 11 is closed on the front surface of the front lens of the optical mechanism portion, and the first link 20 connected to the lens cover 11 at this time is shown. The pin 23 is engaged with the starting end 19a of the first cam groove 19 of the disc cam 16.

When the lens cover 11 is closed, the wide conversion lens 13 is located in front of the front lens, and at this time, the second link 31 is in contact with the cam surface 30a having the larger diameter. There is. Further, the zoom lens 26 is moved to the zooming position, and at this time, the pin 29 protruding from the zoom lens 26 is engaged with the outer peripheral groove 25 a of the second cam groove 25.

Now, for example, when the standby switch is operated from the state of FIG. 5a, the zoom drive motor 8 is driven and the disc cam 16 is rotationally driven in the clockwise direction via the output gear 18 thereof. The rotation of the disc cam 16 causes the first
Since the pin 23 of the link 20 comes closer to the shaft 14 of the disc cam 16 along the first cam groove 19, the fulcrum shaft 22
, So that the other end of the first link 20 supporting the lens cover 11 moves downward, and the lens cover 11 begins to open downward (see FIG. 5b).

The lens cover 11 is completely opened when the disc cam 16 is rotated by about 45 ° (see FIG. 5c). In the state shown in FIG. 5C, the zoom lens 26 is in the zooming position, so that the zoom photographing state is further changed to the wide-angle photographing state by the wide conversion lens 13.

When the disc cam 16 is rotationally driven counterclockwise from the state shown in FIG. 5c, the operation opposite to the above is performed and the lens cover 11 is closed.

Switching Operation of Wide Conversion Lens FIG. 6A shows the open state of the lens cover 11 described above (see FIG. 5).
The second link 31 of the wide conversion lens 13 is located at the same position as in (c).
Is engaged with the cam surface 30a having a large diameter, and the pin 29 of the zoom lens 26 is provided with the outer peripheral groove 2 of the second cam groove 25.
5a is engaged.

Now, from the wide-angle photographing state by the wide conversion lens 13 described above, the disc cam 16 is moved.
When is further rotated clockwise, the second link 31 moves to the cam surface 30b having a smaller diameter. As a result, the tip of the second link 31 is moved downward by the fulcrum of the spring 34 with the fulcrum pin 32 as the fulcrum, and the wide conversion lens 13 supported by the tip of the second link 31 is moved downward. Begins to slide to (Fig. 6
b).

Then, when the disc cam 16 rotates by about 45 °, the second link 31 is located on the cam surface having the smallest diameter of the cam surface 30, and the wide conversion lens 13 is completely moved as shown in FIG. 6c. It will be released. This state is the shooting state in the maximum zooming state of the zoom lens 26.

When the disc cam 16 is driven to rotate counterclockwise from the state shown in FIG. 6c, the wide conversion lens 13 moves upward, and the operation reverse to the above is performed to determine the usage state of the wide conversion lens 13. Become.

Zooming Operation of Zoom Lens FIG. 7a shows the same position as the open state (FIG. 6c) of the wide conversion lens 13 described above, and in this state,
The zoom lens 26 has not moved yet, and the pin 29 of the zoom lens 26 is engaged with the end of the outer peripheral groove 25a of the second cam groove 25.

When the disc cam 16 further rotates clockwise from the maximum zooming state of the zoom lens 26 described above, the pin 29 of the zoom lens 26 moves to the inner peripheral groove 25b of the second cam groove 25 by the cam action. The zoom lens 26 moves backward along the guide hole 28 of the lens barrel 7 (FIG. 7b). The backward movement of the zoom lens 26 is the most retracted state at the position shown in FIG. 7c where the disc cam 16 is rotated by about 45 °, and this position is the standard photographing state. In other words, the zoom lens 26 is shown in FIGS.
Zooming variable magnification operation is possible in the moving range up to.

As described above, in the lens cover drive mechanism of the present invention, the disc cam 16 for driving the zoom lens 26 is rotationally driven by the zoom drive motor 8, and the lens cover 11 is interlocked with the rotational drive of the disc cam 16. Can be automatically opened and closed and the wide conversion lens 13 can be switched. The lens cover 11 can be automatically opened and closed by switching to the camera mode by electrification. It is possible to prevent forgetting to open 11 and forgetting to close the lens cover 11 in the non-photographing state.

Further, since the drive source can be mechanically used, it is not necessary to add an expensive motor dedicated to the lens cover 11, and a simple mechanism for adding the disc cam 16 and the two links 20 and 31 is possible. Becomes

In the embodiment of the lens cover driving mechanism of the present invention, the opening / closing operation of the lens cover 11 and the switching operation of the wide conversion lens 13 can be continuously performed in conjunction with the driving operation of the zoom lens 26. Although the case has been described, at least a mechanism for opening and closing the lens cover 11 in association with the driving of the zoom lens 26 and a mechanism for switching the wide conversion lens 13 in association with the driving of the zoom lens 26 are provided. If you have.

Further, in the lens cover drive mechanism of the present invention, the case where the disc cam 16 for driving the zoom lens 26 is electrically driven by the cam drive motor 8 has been described. For example, the disc cam 16 can be directly manually rotated. It may be driven.

The lens cover drive mechanism of the present invention is
By using the position switch to detect the opening / closing of the lens cover and the positions of the wide conversion lens 13 and the zoom lens 26, it is possible to configure an electric system or a manual system. This position switch can be provided on the surface of the disc cam 16.

The present invention is not limited to the embodiments described above and shown in the drawings, and various modifications can be made without departing from the scope of the invention.

For example, the wide conversion lens 13
The second link 31 that performs the switching operation is moved up and down in accordance with the rotation of the cam surface 30 formed on the disc cam 16. However, the second link 31 is also similar to the first link 20 in the cam groove. You may make it operate | moved by being guided to.

In the embodiment, the wide-angle conversion lens 13 is used as the conversion lens, but a tele (telephoto) conversion lens can be used.

[0037]

As described above, in the lens cover driving mechanism according to the present invention, the lens cover is opened / closed via the movement transmitting mechanism which is interlocked with the movement of the zoom lens which is zoomed by the zoom lens driving means. Because I did
The lens cover can be automatically opened and closed without manually opening and closing, and as a result, forgetting to open the lens cover in the shooting standby state and forgetting to close the lens cover in the non-shooting state can be prevented.

Further, since the drive source can be mechanically used as well, it is not necessary to separately provide an expensive motor dedicated to the lens cover, and a motion transmitting mechanism having a simple structure can be added, resulting in an inexpensive mechanism.

[Brief description of drawings]

FIG. 1 is a perspective view of a camera-integrated VTR equipped with a lens cover driving mechanism of this example.

FIG. 2 is a perspective view of a lens cover drive mechanism of this example.

FIG. 3 is a front view of a lens cover driving mechanism of this example.

FIG. 4 is a plan view of a lens cover driving mechanism of this example.

FIG. 5 is an opening / closing operation diagram of a lens cover.

FIG. 6 is a switching operation diagram of a wide conversion lens.

FIG. 7 is a zooming operation diagram of the zoom lens.

[Explanation of symbols]

 1 Camera-integrated VTR 2 Body 3 Optical mechanism 7 Lens barrel 8 Zoom drive motor 11 Lens cover 13 Wide conversion lens 14 Shaft 16 Disc cam 17 Reduction mechanism 18 Output gear 19 First cam groove 20 First link 22 fulcrum shaft 23, 24 pin 25 second cam groove 26 zoom lens 28 guide hole 29 pin 30 cam surface 31 second link 32, 33 pin 34 spring

Claims (3)

[Claims] 1. A zoom lens driving means performs a zooming operation of a zoom lens via a motion transmission mechanism, and a lens cover is opened / closed via the motion transmission mechanism in association with the movement of the zoom lens. A lens cover drive mechanism characterized by. 2. The lens cover drive mechanism according to claim 1, wherein the motion transmission mechanism is a cam mechanism. 3. The lens cover drive mechanism according to claim 1, wherein the conversion lens is also opened / closed via the operation transmission mechanism in association with the movement of the zoom lens.