JP3565195B2 - Optical unit - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical unit, and for example, relates to an optical unit suitable to be incorporated in a camera.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, for example, a camera in which a lens barrel extends from a camera body is provided with a barrier that covers a front surface of the lens barrel when retracted. There are two types of such barriers.
[0003]
First, the barrier is attached to the exterior of the camera. Considering the inherent function of the barrier for protecting the lens barrel, it is desirable that the barrier be integral with the lens barrel. In this type, however, the barrier must be separated from the lens barrel. In addition, a special interlocking mechanism is required to interlock the driving of the barrier with the driving of the lens barrel, which complicates the configuration.
[0004]
Second, a type in which a barrier is provided in the lens barrel. In this type, it is easy to drive the barrier in conjunction with the driving of the lens barrel. However, since the barrier is provided around the front lens in the lens barrel, the lens barrel becomes larger as a whole. In particular, in the case of a lens barrel for a digital camera, the diameter of the front lens tends to increase, and it is difficult to provide a barrier in the lens barrel and reduce the size of the lens barrel.
[0005]
On the other hand, if an optical unit whose performance is guaranteed is integrated into a camera by integrating mechanical elements such as a lens barrel and a finder, handling in manufacturing the camera becomes easy. In that case, it is desired that the barrier be included in the optical unit and the optical unit be reduced in size.
[0006]
[Problems to be solved by the invention]
Therefore, a technical problem to be solved by the present invention is to provide an optical unit that can be reduced in size even if a barrier is included.
[0007]
[Means for Solving the Problems]
The present invention provides an optical unit having the following configuration in order to solve the above technical problem.
[0008]
In the first aspect of the invention, the optical unit includes a lens barrel, a finder and a barrier movable to and retracted position retracted from the closed position and the front surface for covering the barrel from the front, the driving force for driving at least the barrier And a driving force transmitting mechanism for transmitting the driving force, wherein the lens barrel and the finder are integrally coupled to form a unit on which the barrier driving actuator is mounted , and the unit includes the barrier and the driving force transmitting mechanism. Is installed.
[0009]
In the above configuration, the barrier protects the lens barrel by covering the front surface of the lens barrel in the closed position. The driving force transmission mechanism may transmit the driving force to a lens barrel or a finder other than the barrier. In addition, a drive source such as a motor may be included (coupled) to the optical unit.
[0010]
According to the above configuration, since the related mechanical elements are integrally connected as an optical unit, they can be handled collectively, and a predetermined performance as the optical unit can be guaranteed. Therefore, in various devices, the production, management, assembling work, and the like of parts can be simplified and made more efficient by incorporating the optical unit.
[0011]
According to the above configuration, since the barrier is provided separately from the lens barrel, the lens barrel can be reduced in size, and the optical unit as a whole can be reduced in size by including the barrier.
[0012]
In the first aspect, the optical unit moves to the lens barrel, the finder, a closed position covering the front surface of the lens barrel, and a retracted position retracted from the front surface and positioned in a space between the lens barrel and the finder. A possible barrier and a driving force transmission mechanism for transmitting at least a driving force for driving the barrier are integrally connected.
[0013]
According to the above configuration, by driving the barrier into the space between the lens barrel and the finder , in the width direction, that is, in the direction perpendicular to both the direction connecting the lens barrel and the finder and the optical axis direction of the lens barrel. In addition, the size of the optical unit can be reduced. Also, in the vertical direction, the barrier is laid out due to the finder optical path restriction, so that the size does not increase. In other words, the viewfinder is located at a certain distance from the lens barrel in order to prevent the lens barrel from being seen when viewing the angle of view during shooting, so there is always a certain gap between the viewfinder and the lens barrel. ing. Since the barrier is laid out in this gap, the size does not increase.
[0014]
Preferably, at least a part of the barrier is transparent.
[0015]
According to the above configuration, even if all or a part of the barrier enters the optical path of the finder, if the part is transparent, the finder image can be substantially not affected. Therefore, it is possible to further reduce the size of the optical unit in the direction connecting the lens barrel and the finder by reducing the distance between the lens barrel and the finder.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an optical unit according to an embodiment of the present invention will be described with reference to FIGS. 1 is a front view, FIG. 2 is a right side view, and FIGS. 3 and 4 are left side views.
[0017]
The optical unit 10 generally includes a lens barrel 2, a finder 4, a barrier 6, a barrier driving force transmission mechanism 8 for transmitting a driving force to the barrier 6, and driving actuators (a zoom motor 20 and a barrier driving motor 40). It is integrally connected. The optical unit 10 is incorporated in a camera, for example, a digital camera.
[0018]
As shown in FIG. 1, an objective window 12 of the finder 4 is provided on the front of the optical unit 10, and an eyepiece window 14 of the finder 4 is provided on the back. As shown in FIGS. 1 to 3, the lens barrel 2 is retracted in a non-photographing state, and its front surface is covered with a barrier 6.
[0019]
In the photographing state, as shown in FIG. 4, the barrier 6 is pushed upward, and the lens barrel 2 is extended as indicated by a chain line. The projection amount (extending amount) of the lens barrel 2 becomes large at a wide angle, but even in this case, the lens barrel 2 is prevented from entering the optical path F of the finder 4 having a large viewing angle. That is, the viewfinder 4 is disposed at a certain distance from the lens barrel 2 in order to prevent the lens barrel 2 from being seen when viewing the angle of view during shooting, and a certain distance is provided between the viewfinder 4 and the lens barrel 2. There are gaps (spaces). The barrier 6 is retracted using the gap.
[0020]
The lens barrel 2 is composed of a plurality of cylinders that are relatively rotatable, like a general zoom lens barrel for a lens shutter camera. The lens barrel 2 is driven by a zoom motor 20 to expand and contract, each lens group moves to a predetermined position, and the focal length changes. The driving force includes an output gear 22 fixed to the output shaft of the zoom motor 20, a reduction gear (not shown) disposed in a hatched portion 24 in FIGS. 1 and 2, and an optical axis of the lens barrel 2. It is transmitted via a long gear 26 arranged in parallel with O.
[0021]
The finder 4 includes a movable unit 36 that holds a lens or a mirror. The movable unit 36 has a sleeve 34 inserted through the guide shaft 38. A cam follower 35 protrudes from the sleeve 34 so as to engage with a cam groove 32x (see FIGS. 3 and 4) formed in the finder drive cam 32. The rotation of the zoom motor 20 is transmitted to the finder driving cam 32 by a gear train (not shown), and the finder driving cam 32 rotates in conjunction with the driving of the lens barrel 2. As a result, the movable unit 36 moves in response to a change (zooming) in the focal length of the lens barrel 2, and the finder image is scaled.
[0022]
The barrier 6 includes three movable plates 15, 16, and 17, as shown in FIGS. The movable plates 15, 16, 17 are guided on the left and right sides by a guide unit (not shown) so as to move in a plane orthogonal to the optical axis O. Protrusions 15a, 15b, 16a, 16b, 16c, 17a are provided at the ends of the movable plates 15, 16, 17, and the projections 15a, 15b, 16a, 16b, 16c, 17a are successively hit, and the adjacent movable plates 15 , 16 and 17 are pushed up or down to open and close the barrier 8. FIG. 4 shows the closed state of the barrier 6, and the movable plates 15, 16, 17 are in a closed position covering the front surface of the lens barrel 2. FIG. 3 shows the opened state of the barrier 6, and the movable plates 15, 16, 17 are in a retracted position retracted from the front surface of the lens barrel 2.
[0023]
The barrier 6 is driven by a barrier drive motor 40 via a barrier drive force transmission mechanism 8.
[0024]
That is, as shown in FIGS. 3 and 4, on the left side surface of the optical unit 10, the gear trains 42, 43, 44a and the barrier drive lever 46a are arranged. One end of the barrier drive lever 46a is rotatably supported, and is provided with a gear 47a that meshes with the gear 44a. A projection 48a is provided at the other end of the barrier drive lever 46a, and engages with an engagement groove 17n provided in the projection 17t of the lowermost movable plate 17.
[0025]
As shown in FIG. 2, a gear 44b and a barrier drive lever 46b are disposed on the right side surface of the optical unit 10. The barrier drive lever 46b has the same configuration as the barrier drive lever 46a on the left side, is rotatably supported at one end, is provided with a gear portion 47b that meshes with the gear 44b, and is provided with a projection 48b at the other end, and is movable. The projection 17 engages with an engagement groove 17 m provided in the projection 17 s of the plate 17. As shown in FIG. 1, the gears 44a and 44b are fixed to both ends of the connecting shaft 46, and are configured to rotate integrally.
[0026]
When the barrier drive motor 40 rotates, the barrier drive levers 46a and 46b rotate via the output gear 42 fixed to the output shaft and the gears 43, 44a and 44b, and push up or move down the lowermost movable plate 17. As a result, the barrier 6 opens and closes along left and right guides (not shown).
[0027]
The barrier drive motor 40 drives the barrier 6 in the direction from the closed state to the open state by turning on the start switch of the camera. Next, the zoom motor 20 is driven, the lens barrel 2 is extended, and the camera is ready for photographing.
[0028]
After the photographing, the zoom motor 20 is driven in the reverse direction, and the lens barrel 2 is retracted. When the end of the retraction of the lens barrel 2 is detected, the barrier drive motor 40 drives the barrier 6 in a direction to change the state from the open state to the closed state.
[0029]
As described above, the optical unit 10 utilizes the space between the lens barrel 2 and the finder 4 to dispose the zoom motor 20, the barrier drive motor 40, and the drive mechanisms 24 and 26 of the lens barrel 2. In addition, a barrier driving force transmission mechanism 8 having a small thickness is provided on the side surface to reduce the overall size.
[0030]
Since the optical unit 10 is provided with the barrier 6 separately from the lens barrel 2, the lens barrel 2 can be downsized, and the optical unit 10 as a whole can also be downsized by including the barrier 6. is there.
[0031]
Further, by moving and opening and closing the barrier 6 in a direction connecting the lens barrel 2 and the finder 4, the barrier 6 is moved in a direction perpendicular to both the direction connecting the lens barrel 2 and the finder 4 and the optical axis direction of the lens barrel 2. In addition, the size of the optical unit 10 can be reduced.
[0032]
The present invention is not limited to the above embodiment, but can be implemented in various other modes.
[0033]
For example, at least a part of the barrier may be made transparent, and the objective window or the like of the finder may be covered when the barrier is open, so that the part may be made transparent. Thus, the size of the optical unit can be further reduced in the direction connecting the lens barrel and the finder.
[0034]
For example, in this embodiment, the barrier drive motor is provided separately from the zoom motor, but a zoom motor may be used.
[0035]
Further, the driving actuator may be provided separately from the optical unit. Conversely, a light measuring unit, a distance measuring unit, and the like may be included in the optical unit and integrated.
[Brief description of the drawings]
FIG. 1 is a front view of an optical unit according to an embodiment of the present invention.
FIG. 2 is a right side view of the optical unit of FIG.
FIG. 3 is a left side view of the optical unit in FIG. 1;
FIG. 4 is a left side view of the optical unit in FIG. 1; This shows a state where the barrier is open.
[Explanation of symbols]
2 Lens barrel 4 Finder 6 Barrier 8 Barrier drive force transmission mechanism (drive force transmission mechanism)
10 Optical unit

Claims (3)

Comprising a barrel, a finder, a barrier movable to and retracted position retracted from the closed position and the front surface for covering the barrel from the front, and a driving force transmission mechanism for transmitting a driving force for driving at least the barrier Wherein the lens barrel and the finder are integrally connected to form a unit on which the barrier driving actuator is mounted , and the unit is provided with the barrier and the driving force transmission mechanism. , Optical unit. A lens barrel, a finder, a barrier movable to a closed position covering the front surface of the lens barrel and a retracted position retracted from the front surface and located in a space between the lens barrel and the finder, and driving at least the barrier An optical unit, wherein a driving force transmitting mechanism for transmitting a driving force to be transmitted is integrally coupled. The optical unit according to claim 1, wherein at least a part of the barrier is transparent.

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