JPS59166927A - Direct-view finder camera - Google Patents

Abstract

PURPOSE:To confirm whether the operation of a shutter is correct or not without obstructing the observation of a finder by displacing a light shielding member between a light shielding position for shielding a lens transmitting light by covering the front of the shutter, and a position shunted from said position. CONSTITUTION:A light shielding member 13 is driven by arms 15, 16 between a light shielding position for covering the front of a shutter shielding a photographic picture frame 14, and a shunted position shunted from the front of the shutter. A movable image of a finder is observed from an incident surface 5a of a prism, but when the light shielding member 13 is at a light shielding position, a light shielding plate 10 which is supported by a shaft 19 and controls a finder luminous flux is shunted from the incident surface 5a, therefore, the movable image can be observed in the finder, and prior to an exposure, focusing can be executed. When the light shielding member 13 is moved to the shunted position, the light shielding plate 10 covers the incident surface 5a, therefore, the exposure operation can be confirmed without obstructing an observation of an object to be photographed. Accordingly, whether an operation of the shutter is correct or not can be confirmed from the finder.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a perspective viewfinder camera, and more particularly to a perspective viewfinder camera including a focal plane shutter and a light shielding member disposed in front of the focal plane shutter.

(Background of the invention) Conventionally, this type of camera was disclosed in Japanese Patent Application Laid-Open No. 55-164818.
There is something disclosed in the publication No. This camera includes a light shielding member movable between a light shielding position that covers the front surface of the shutter and blocks light transmitted through the photographing lens that is about to enter the shutter, and a retracted position that is retracted from the front surface of the shutter, and the light shielding member. The shutter is provided with a drive mechanism for displacing the shutter from the light-shielding position to the retracted position immediately before the exposure operation, and for displacing the shutter from the retracted position to the light-shielding position immediately after the exposure operation.

This light shielding member has a function of preventing light leakage of the film and burnout of the shutter curtain due to direct irradiation of the shutter curtain with light transmitted through the lens.

By the way, when comparing such a see-through finder with a single-lens reflex camera, the former differs in that the finder light beam is not blocked by a quick return mirror during exposure, unlike the latter. This difference can be said to be an advantage of a see-through viewfinder camera because it allows you to observe the subject even at the moment of exposure.
On the other hand, this can be said to be a drawback of perspective cameras for the following reasons. In other words, the darkening of the viewfinder in an eye reflex camera has the effect of indicating to the user that the quick return mirror and, by extension, the shutter that is linked to it, have been operated reliably.
A perspective finder camera does not have this effect.

(Object of the Invention) An object of the present invention is to obtain a see-through finder camera that allows confirmation of correctness or failure of shutter operation from the finder without obstructing observation through the finder.

(Summary of the invention) For this purpose, the present invention provides 1. A finder light flux control mechanism that changes a part of the finder light flux in conjunction with the light shielding member is provided.

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

FIG. 1 shows the planar arrangement of a rangefinder system, which is a type of perspective finder.

An objective lens 1, prisms 2 and 3, and an eyepiece 4 constitute a fixed image optical system, and a prism 5, a movable lens 6, a frame plate 7, a lens 8, a prism 3, and an eyepiece 4 constitute a movable image optical system. There is.

In front of the entrance surface 5a of the prism 5, a light shielding plate 10 is provided as a finder light flux control means. The movable lens 6 swings around point X in response to focus adjustment of the photographic lens.

The object light incident on the objective lens 1 passes through the prisms 2 and 3 and the eyepiece 4 to form a fixed image on the incident surface 5a of the prism 5.
The object light incident on the camera passes through a movable lens 6, a frame plate 7, a lens 8, a prism 3, and an eyepiece 4 to become a movable image.

FIG. 2 shows a finder screen, in which a fixed image is observed over the entire screen 11, and a movable image is observed within a central frame IJ2 defined by the frame plate 7, overlapping with the fixed image. When the focus is adjusted, the movable lens 6 swings, and the movable image is displaced in the horizontal direction in the figure. When the movable image matches the fixed image, the photographing lens is adjusted to the in-focus position.

Figures 3 and 4 show the light shielding member 13 and its drive mechanism 15 to 1.
7.

FIG. 3 shows that the light shielding member 13 is in the light shielding position, that is, in the photographing image frame 14.
FIG. 4 shows a state in which it is in a position covering the front surface of the shutter that blocks the shutter, and a state in which it is in a retracted position, that is, a position retracted from the front surface of the shutter.

In both figures, the light shielding member 13 is pivotally attached to parallel arms 15 and 16, and the arms 15 and 16 are supported by shafts 17 and 18 on a shutter board (not shown), and are operated in conjunction with a shutter mechanism (not shown). The light shielding member 13 is displaced along a plane perpendicular to the optical axis of the light transmitted through the lens. With the shirt release operation, the light shielding member 13 moves from the light shielding position (Fig. 3) to the retracted position (
Figure 4). After that, the front and rear shutter curtains run. When the trailing curtain completes running, the light shielding member 13 returns from the retracted position to the light shielding position. Of course, this light shielding member 13
The timing of the quick return operation is set strictly so as not to disturb the exposure.

The light shielding plate 10 is pivotally supported by a shaft 19, and interlocks with the arm 15 through fitting between a fork-shaped groove 10a formed at the lower end and a bottle 15a planted on the arm 15.

When the light shielding member 13 is in the light shielding position as shown in FIG.
The light shielding plate 10 is located at a position retracted from the front surface of the entrance surface 5a of the prism 50. Therefore, the movable image can be observed within the central frame 12, and focus adjustment can be performed prior to exposure.

From the release operation until the trailing curtain travels, the light shielding member 13 retreats to the retracted position as shown in FIG. 4, and the light shielding plate 10 is displaced to a position covering the front surface of the entrance surface 5a of the prism 5. Therefore, the object light to the prism 5 is blocked, and the movable image and the central frame 12 disappear during exposure. This allows the user to check the exposure operation without being obstructed from observing the subject.

In this embodiment, the movable image and the center frame are erased, but if a colored transparent member is used in place of the light shielding plate 10, the image within the center frame will be colored during exposure, making it possible to confirm the exposure operation. can.

However, the present invention is not limited to rangefinder cameras as in this embodiment, but can also be applied to other perspective finder cameras, such as daylight type prite frame finders. In this case, a member corresponding to the light shielding plate may be inserted and removed in the optical path forming the field frame. If this happens, the field frame will disappear or become colored during exposure.

(Effects of the Invention) As described above, according to the present invention, the exposure operation can be confirmed without obstructing viewfinder observation.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a finder system according to an embodiment of the present invention, FIG. 2 is a diagram showing a finder screen by the finder system, and FIGS. 3 and 4 show the main mechanism of the embodiment. It is a diagram. (Explanation of symbols of main parts) 13... Light shielding members 15 to 17... Drive mechanism 10...
... Finder light flux control means applicant Takao Watanabe, agent of Nippon Kogaku Kogyo Co., Ltd. Figure 11, Figure 3! '-4 figure (n

Claims (1)

[Claims] (1) In a camera equipped with a focal plane shutter and a see-through finder, there is a light-shielding position that covers the front surface of the shutter and blocks light transmitted through the photographing lens that is about to enter the shutter, and a retracted position that is retracted from the front surface of the shutter. a light-shielding member that is movable between; the light-shielding member is displaced from the light-shielding position to the retracted position when the exposure operation of the shutter starts; and the light-shielding member is displaced from the retracted position to the light-shielding position when the exposure operation of the shutter is completed; A see-through finder camera comprising: a drive mechanism; and finder light flux control means that changes part of the light flux of the see-through finder in conjunction with the drive mechanism.