JPH0743826A - Picture size changing mechanism for optical instrument and the like - Google Patents

Abstract

PURPOSE:To reduce space where a blade for changing a picture size is withdrawn, in a picture size changing mechanism mounted in a compact camera, etc. CONSTITUTION:The sizes in a vertical direction of the blades 12 and 13 as a picture size changing member are made smaller than those of the conventional blades, while second blades 14 and 15 capable of being withdrawn to hide behind the blades 12 and 13, respectively are provided. Therefore, when a photographic picture is set for a large picture, the blades 12 and 13 are moved into up and down directions respectively, simultaneously, the blade 14 is hidden behind the blade 12 and the blade 15 is hidden behind the blade 13, so that the space (space in the vertical direction) where a blade group is withdrawn can be reduced than that in the conventional practice.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen size changing mechanism for optical devices such as cameras that can be used.

[0002]

2. Description of the Related Art Almost all recent non-interchangeable lens type cameras (compact cameras) are equipped with a screen size changing mechanism. Therefore, the photographing screen can be changed to a standard screen or a panoramic screen (reduced screen) according to the photographing situation. You can choose to either.

Conventionally, as this type of mechanism, there has been known a mechanism for changing the aperture size by using two blades as shown in FIG.

In the figure, 1 is a knob which is an operating member, 2 and 3 are blades for changing the aperture size, 6 is a ring for moving the blades 2 and 3 up and down,
Is.

When the knob 1 is moved left and right, the ring rotates about the optical axis because the projection 1-a of the knob 1 and the recess 6-a of the ring 6 are fitted together. At this time, the protrusions 2-a of the blades 2 and the protrusions 3-a of the blades 3 move in the up-down direction in accordance with the rotational movement of the ring, and the aperture size changes in the up-down direction.

[0006]

In the above-mentioned conventional example, since the vertical dimension of the blade is quite large, a considerable space above and below the aperture is required as a retracting space for the blade, which has a drawback of hindering downsizing of the camera. .

It is an object of the present invention to provide a screen size changing mechanism that eliminates the aforementioned drawbacks of the prior art.

[0008]

In order to store as many members as possible in a place having a fixed volume or a fixed area, it is necessary to store the members in the place so as to overlap each other.

In the screen size changing mechanism according to the present invention, each of the upper and lower blade members is formed on the basis of the above-mentioned reason, and the blade members can be housed so as to overlap each other in the front-back direction (parallel to the screen) at the retracted position. It was configured like this. As a result, the vertical dimension of one blade can be reduced, and the vertical dimension of the retreat place for retracting the blade can also be reduced, so that optical equipment such as a camera can be downsized.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> FIGS. 1 to 3 show the aperture size changing mechanism (screen size changing mechanism) of the first embodiment of the present invention.
Indicates. In the figure, 1 is a knob as an operation member, 12 and 13 are first blades for changing the aperture size, and 14 and 15 are also second blades. Reference numeral 16 is a ring for driving the blades 12 to 15 up and down.

In FIG. 3, an operating member or knob 1
Is moved to the left, the protrusion 1-a of the member 1 and the ring 1
Since the concave portions 16a of 6 are fitted, the ring 16 is driven by the movement of the knob 1 to rotate counterclockwise about the optical axis. At this time, the protrusion 12 a of the blade 12 and the protrusion 1 of the blade 13
3a is moved in the upward and downward directions following the rotation of the ring 16, and the aperture size is enlarged as shown in FIG.
Further, the protrusions 14a and 15a of the second blades 14 and 15
Is driven by the rotation of the ring 16, and the blades 14 and 15 move up and down so as to enter the rear side of the blades 12 and 13, and the state shown in FIGS. 1 and 2 is obtained. Incidentally, the knob 1 is provided with a stopper (not shown) so that the blades can be stopped at a plurality of positions corresponding to the panorama size and the high definition size.

According to the structure of the present invention, since the blade can be made smaller in the vertical direction than in the conventional case, it can be housed in a retreat having a smaller vertical dimension than in the conventional case, and therefore the camera can be miniaturized. It will be possible.

<Second Embodiment> FIG. 4 shows a second embodiment of the present invention. In the figure, 11 is a knob which is an operation member, 23 and 24 are first blades for changing the aperture size, and 25 and 26 are second blades. Reference numeral 22 denotes a lever for moving the first blades 25 and 26 up and down, which is pivotally attached to the second blade 23 by a pin 22a and is pivotally attached to another first blade 24 by a pin 22b. .

When the operating member 11 is moved left and right, the first blades 23 and 24 are moved upward and downward by a known link mechanism. Since the second blades 25 and 26 are pressed against the first blades 23 and 24 by a spring member (not shown), they move as the upper and lower first blades move. It should be noted that the first and second blades 23 to 26 and a guide member (not shown) are guided so that they can move only in the vertical direction. Further, the operation member 11 is provided with a plurality of stoppers (not shown) so that the operation member 11 can be stopped at a position corresponding to a panorama size or a high definition size. Therefore,
The blades 23 to 26 can also be fixed at the stopper position, and the screen size can be set to several screen sizes (for example, panorama size and high definition size).

[0016]

As described above, in the screen size changing mechanism according to the present invention, the vertical dimension of the blade or frame member which is the screen size changing member is smaller than that of the conventional mechanism, and Since the device is configured so that when the screen becomes a large screen, the blades or the frame members are housed in a retreat space outside the outer edge of the screen with the blades or the frame members overlapping with each other in the front-rear direction, the retreat space is also more The size can be reduced, and as a result, the screen size changing mechanism of the present invention can reduce the size of optical equipment such as a camera.

[Brief description of drawings]

FIG. 1 is a perspective view of a screen size changing mechanism according to a first embodiment of the present invention, showing a state in which a screen is a large size screen (standard screen).

FIG. 2 is a front view of the screen size changing mechanism in the state of FIG.

FIG. 3 is a front view of a state where the screen size changing mechanism of the first embodiment is set to a small screen state.

FIG. 4 is a front view of a screen size changing mechanism according to a second embodiment of the present invention.

FIG. 5 is a perspective view of a conventionally known screen size changing mechanism.

[Explanation of symbols]

1, 11: Knobs (operating members) 2, 3, 12, 13, 14, 15, 23, 24, 25,
26: blade 6, 16: ring 22: lever

Claims (2)

[Claims] 1. A screen size changing mechanism for changing the screen size of an optical device or the like, comprising a plurality of blade members or frame members for changing the screen size, the blade member or frame member being When the vertical dimension of the screen is enlarged, the screen is housed in a retracted position above the screen and a retracted position below the screen, and at the retracted position, the blade member or the frame member is parallel to the screen. A screen size changing mechanism for an optical device or the like, which is configured to be housed so as to overlap each other in the front-rear direction. 2. The screen size changing mechanism according to claim 1, wherein the blade member or the frame member is configured to be fixed at a plurality of points before reaching the retracted position.