JPH073394Y2 - Interchangeable viewfinder device for single-lens reflex camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a screen correction mechanism for an interchangeable viewfinder of a camera.

[Conventional technology]

Conventionally, a camera in which various screens can be replaced has been known, and several types of finder screens such as a micro prism type and a full-face mat type are prepared. However, since the transmission / diffusion characteristics of light generally differ depending on the type of the finder screen, when the type of the finder screen is changed, it may not be possible to display the proper exposure in a camera that has a photometric device in the camera finder and performs screen photometry. Will occur.

A method called screen correction is known to solve the above-mentioned problems. This is a viewfinder photometric camera, in which the reference data that provides the correct exposure when photometry is performed using a finder screen with a certain transmission / diffusion characteristic is prepared, and a screen with a transmission / diffusion characteristic different from that of the finder screen is used. When photometry is performed, the proper exposure can be displayed by giving the difference between the obtained exposure data and the reference data as a correction amount to the camera body in advance.

FIG. 3 shows an example of a replaceable finder having a screen correction means of this type conventionally.

Since the system shown in FIG. 3 can be operated outside the viewfinder, the screen correction dial (31) provided in the interchangeable viewfinder (1), which will be referred to as an external type hereinafter, is a member having a shaft penetrating inside the viewfinder. However, although not shown in the figure, it is in an engaged state with the screen correction mechanism inside the finder. Further, on the screen correction dial (31), scales (31a) to (31e) corresponding to the respective screen correction values are arranged at predetermined positions. The above scales (31a) to (31e) are aligned with the index (32) arranged on the finder.

On the other hand, there is also known a conventional example in which the operation member of the screen correction mechanism is provided in a place where the lower surface of the finder cannot be seen from the outside during normal shooting, that is, a place which cannot be seen from the outside when the finder is attached to the camera body. .
This conventional example is hereinafter referred to as an internal type, in contrast to the external type.

4 and 5 show an example of the internal formula. FIG. 4 shows the internal structure. The operation gear (41) is rotatably fitted to the finder bottom portion (1a), and the end portion (42) is configured to project to the outside of the finder. The end portion (42) is provided with a cross-shaped groove (43) and an index (not shown), and the "+" or "-" shaped driver (not shown) that fits the cross-shaped groove is provided from outside the viewfinder. The operation gear (41) is rotatable. The gear portion (45) of the operation gear (41) is in engagement with the correction gear (46). The correction gear (46) engaging with the operation gear (41) is provided with a sliding brush (47), and a plurality of patterns (48a) to ((a) arranged on the pattern substrate (48) are provided. 48b) It is configured to slide on to bring the pattern into conduction.

Therefore, by the driver (not shown), the operation gear (41)
When the index is aligned with the scale disposed outside the finder lower part (1a) by rotating the, the sliding brush (47) of the correction gear (46) in engagement with the operation gear (41) becomes The screen is corrected by sliding on the patterns (48a) and (48b) to bring the patterns into conduction.

Further, as shown in FIG. 5, the end portion (42) of the operation gear (41) is arranged at a position under the finder which cannot be seen from the outside during normal photographing.

[Problems to be solved by the invention]

In the conventional technique as described above, there is an advantage that the operation member for screen correction in the external type is exposed to the outside so that the scale on the operation member and the correction value set by the index of the finder can be immediately known. On the other hand, there is a drawback that the viewfinder becomes large and the operation members of the camera body around the viewfinder are obstructed because the operation member is outside.

Further, even in the internal type, since the operation member is in a position not visible from the outside, there is an advantage that the screen correction mechanism can be downsized, the viewfinder itself can be downsized, and the appearance is preferable, but the scale on the operation member is externally visible. Since it cannot be confirmed, there is a drawback that it takes time and effort to remove the finder from the camera body each time to confirm the set correction value.

The present invention has been made in view of the above problems, and it is necessary to dispose the operation member for screen correction in a position that cannot be seen from the outside during normal shooting, and to remove the correction amount set from outside the viewfinder from the body. It is to provide a finder device that can be checked without any trouble.

[Means for solving problems]

In order to solve the above-mentioned problems, in the present invention, an operation member for adding screen correction is arranged at a position below the replaceable finder that is not visible from the outside during normal use of the replaceable finder and set. The structure is such that the correction amount can be confirmed directly from the outside.

〔Example〕

An embodiment of a finder device having a screen correction mechanism according to the present invention is shown in FIGS.

The crown gear (11) is rotatably fitted to the finder bottom (1a), and one end (12) of the crown gear (11) is projected to the outside (downward) of the finder.
The end (12) protruding to the outside of the finder is provided with a cross-shaped groove (13), and the cross-shaped groove (13) is provided.
The crown gear (11) can be rotated from the outside of the finder by a "+" or "-" shaped driver (not shown). In addition, the crown gear (1
A crown-shaped gear portion (14) is provided at an end different from the end protruding to the outside of the finder of 1).

The crown-shaped gear portion (14) is in a state of being engaged with the gear portion (16) of the index gear (15) rotatably locked to the side surface portion (1b) of the finder body. On the side of the index gear (15) facing the finder side surface (1b),
Scales such as "-2""-1""0""1""2" (16
a) to (16e) are arranged, and the scale can be confirmed from the outside of the finder through a through hole (17) provided in the side surface portion (1b) of the finder. A sliding brush (18) is provided on the surface of the index gear (11) opposite to the scales (16a) to (16e), and the brush is adjacent to the scales (16a) to (16e). Then, the conductor pattern (19a, 19b, 19c, etc.) corresponding to any of the scales (16a to 16e) facing the through hole (17) is slid on the pattern substrate (19) provided in the finder. It becomes conductive. Then, the conduction signal of the conductor pattern is transmitted to a photometric circuit (not shown) to correct the photometric output error based on the difference in the transmission and diffusion characteristics of the exchange screen arranged on the planned focal plane. That is, the output (photometric output) of the photometric circuit is electrically corrected so that the photometric output does not change even if the amount of light transmitted through the screen changes due to the difference in transmission / diffusion characteristics of each exchange screen, and the corrected photometric output Is used to determine proper exposure. Further, a click groove (20) is provided around the index gear (15), and the bent other end of the click spring (21) having one end fixed to the finder has its own elastic force applied to the click groove (20). 20) is designed to be depressed. Therefore, each time the graduations (16a to 16e) face the through hole (17), the other end of the click spring (21) falls into the click groove (20) to surely hold the graduation indication state. .

As described above, a groove-shaped end (12) of the crown gear (11) is used from the outside of the finder by using a driver (not shown).
When is rotated, the index gear rotates due to the meshing of the crown-shaped end of the crown gear (11) and the index gear. Further, it is possible to set the index gear at the graduation position showing the target screen correction value through the through hole (17).

After correcting the photometric output according to the replacement screen in this manner, the lower surface of the finder, that is, the bottom portion (1a) of the finder from which the end portion (12) of the crown gear (11) projects is fixed to the camera body (2). By facing the finder mounting portion (2a) formed on the upper surface and fixing the finder to the mounting portion (2a), a subject image can be observed at the eyepiece portion of the finder. The end portion (12) is covered with the finder (1) and the camera body (2) and cannot be seen from the outside. In the embodiment described above,
The through hole (17) is provided on the side surface of the viewfinder on the upper side of the winding where the shutter release button (2b) is provided. Front viewfinder side (front) where is provided,
It may be provided either on the rear finder side surface (rear surface) having an eyepiece portion opposite to the front finder side surface or on the upper surface of the finder provided with a hot shoe or the like.

[Effect of device]

As described above, according to the present invention, since the operation member of the screen correction mechanism is arranged in a place which is not visible from the outside at the bottom of the interchangeable finder during normal shooting, that is, when mounted on the camera body, Sometimes this operation member does not get in the way, and a favorable result can be obtained in terms of design. As described above, although the operating member is placed under the viewfinder, the set screen correction amount can be checked through the through-holes provided on the side surface or the upper surface of the viewfinder, so the screen correction amount set during shooting is also set. Has the advantage that it can be confirmed.

[Brief description of drawings]

FIG. 1 is a perspective view showing the outline of an embodiment of the present invention, FIG. 2 is a perspective view showing the relationship between the finder of the above embodiment and the camera body, and FIG. 3 is a replaceable finder having a conventional screen correction mechanism. FIG. 4 is a perspective view showing an internal mechanism of the finder of FIG. 3, and FIG. 5 is a perspective view showing a conventional replaceable finder different from that of FIG. [Explanation of symbols of main parts] 1 ... Finder 2 ... Camera body 11 ... Crown gear 15 ... Index gear 17 ... Through hole

Claims (1)

[Scope of utility model registration request] 1. A correction mechanism for correcting a signal relating to transmitted light of an exchange screen according to a transmission diffusion characteristic of an exchange screen arranged at a focal position, and a correction mechanism for operating the correction mechanism to perform a correction operation. A replaceable finder device for a single-lens reflex camera, which has a manual operating member for tightening, and which is attached to the camera body with the lower surface thereof facing the lower surface of the replaceable finder device. A window for display is provided on a side surface or an upper surface of the interchangeable finder device, and a display member that faces the window and is interlocked with the manual operation member is provided. A viewfinder device that can be displayed externally.