JPH11282052A - Real image system finder mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent dust and dirt from entering a visual field frame placed at a real image position, and also, to facilitate the parallax adjustment. SOLUTION: The visual field frame 4 is fixed to a visual field frame adjusting frame 3, and an objective lens 5 and a relay lens 6 are separately mounted on the frame 3 so as to be positioned before and behind the frame 4, then, the frame 4 is sealed. An engagement part 3a, a pressure applying part 3b, a parallax adjusting arm part 3c are integrally formed with the frame 3, and the frame 3 is inserted and arranged in the finder main lens barrel 1 so as to adjust a parallax.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a real image type optical finder used for an electronic video camera such as a silver halide camera and a digital camera.

[0002]

2. Description of the Related Art A real image finder used in a conventional silver halide camera or an electronic image camera is provided with a field frame mask for specifying a range to be photographed at a real image position of a subject or a field frame mask for transparent glass called focus glass. A field frame on which a target frame is deposited is incorporated. The parallax (parallax) between the taking lens and the finder is adjusted by shifting these field frames.

FIG. 4 shows a conventional example. In the figure, there is shown an example of a real image type finder using a mirror having a fixed focal point.
2, the objective lens group 33, the relay lens 34, the relay lens rear group 35, and the eyepiece 36 are fixed before and after. The field frame adjustment frame 32 is provided with a parallax adjustment arm 32a integrally formed. Further, mirrors 37 and 3 for bending the optical path at right angles to the finder main barrel 30 are provided.
7a is fixed using the mirror holding plates 38, 38a, and is engaged with and fixed by covering the finder covers 39, 40. The parallax adjustment with the photographing lens is performed by shifting the field frame adjustment frame 32 using the parallax adjustment arm 32a formed on the field frame adjustment frame 32. After that, the field frame adjustment frame 32 is bonded and fixed to the main finder barrel 30 at the position where the parallax adjustment is performed.

[0004]

However, in the conventional example, dust and dirt are present in the focus glass viewing frame 31 which is the real image position of the finder main lens barrel 30, and dirt and dust are present through gaps such as the finder cover 39. Or the viewfinder main barrel 30 and the field frame adjustment frame 3
2 may be rubbed during parallax adjustment to generate and adhere to dust and the like.

[0005] There is a serious problem that these dusts and dusts are enlarged and visible. In particular, in the real image type zoom finder, a large opening must be provided on the side of the main body of the finder because it is necessary to move the zooming objective lens group by engaging it with a cam etc. However, there is a major problem that the finder is difficult to see if it adheres to the field frame.

SUMMARY OF THE INVENTION An object of the present invention is to provide a real image type finder mechanism which can prevent dust and dirt from entering a field frame at a real image position and can easily adjust parallax.

[0007]

According to a first aspect of the present invention, a field frame is arranged at a position of a real image of a subject, and the real image is enlarged by an eyepiece. In the viewfinder, the field frame and a middle lens frame in which the finder lens is fixedly arranged before and after the field frame, and at least the objective lens system, the middle lens frame, the relay lens system, and the eyepiece system can be built in at predetermined positions. A main finder barrel, and the middle lens frame is inserted into the main barrel so as to be adjustable in position.

According to a second aspect of the present invention, in the first aspect of the present invention, the parallax is adjusted by moving the middle mirror frame in order to adjust the position of the field frame to correct the parallax. It was done.

According to a third aspect of the present invention, in the configuration of the second aspect, the middle lens frame is positioned and engaged with the main lens barrel in an optical axis direction, and serves as a guide when adjusting parallax. An engagement portion, a pressurizing portion for pressurizing the lens barrel with a certain force or more, and a parallax adjusting arm portion having a surface that is in pressure contact with the lens barrel. is there.

According to the above configuration, the field frame is fixed in a field frame adjustment frame (middle mirror frame) that has been cleaned, and lenses such as an objective system and a relay system are arranged before and after the field frame. By fixing these lens systems to the frame adjustment frame and sealing the field frame with the lens system at the same time, the invasion of dirt and dust is prevented, and the dirt and dust attached to the field frame are not seen in an enlarged manner. .

Further, the parallax adjustment with the photographing lens can be adjusted by moving a field frame adjusting frame (middle mirror frame) having a built-in and sealed field field.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic side view of an embodiment of a finder unit according to the present invention, FIG. 2 is a perspective view showing the configuration of a field frame adjusting frame according to an embodiment of the present invention, and FIG. FIG. 3 is a configuration perspective view of a finder unit, and the same parts are denoted by the same reference numerals in the figures.

In FIG. 1, 1 is a viewfinder main lens barrel (main lens barrel), 2 is an objective lens group, 2a and 2b are moving objective lenses for zooming, 3 is a field frame adjustment frame (middle lens frame),
4 is a field frame, 5 and 6 are finder lenses, 5 is an objective lens 6 is a relay lens, 7 is mirrors 1 and 8 for bending the optical axis at right angles, 8 is the same mirror 2, and 9 relay lens groups behind this. Ten eyepieces are arranged.

Reference numeral 3a denotes a convex joint formed integrally with the field frame adjusting frame 3, 3b denotes a spring pressurizing portion for pressing the field frame adjusting frame 3 to the finder main barrel 1, and 3c denotes a finder. This is a parallax adjusting arm having a surface that comes into pressure contact with the main lens barrel 1. 1a of main viewfinder barrel 1
The reference numeral 1b designates a joint portion which engages with the field frame adjusting frame engaging portion 3a, and 1b designates a parallax adjusting arm 3c of the field frame adjusting frame 3.
The arm has a surface that presses against it.

In FIG. 2, the field frame adjustment frame 3 has a field frame 4
Are adhered or welded, and the objective lens 5 and the relay lens 6 are further attached to the field frame adjusting frame 3, and the field frame 4 is sealed with the objective lens 5 and the relay lens 6.

FIG. 3 is a perspective view showing a configuration of a finder unit of a right-angle optical path type real image type zoom finder according to an embodiment of the present invention. In the figure, a field frame adjustment frame 3 is incorporated from the side of a portion where the optical path where the first real image position of the finder main barrel 1 is located is bent at a right angle. At this time, the engaging portion 1a and the pressurizing portion 3b, which are integrally formed on the engaging portion 1a and the arm portion 1b provided on the finder main barrel 1 with the visual field frame adjusting frame 3, are provided.
The parallax adjusting arm 3c is engaged and inserted.

Here, a variable magnification moving cam 1 for moving the objective lens group 2, the variable magnification movable objective lenses 2a and 2b, and the variable magnification movable objective lenses 2a and 2b to the main viewfinder barrel 1.
5, a shaft 16 serving as a guide for the moving objective lens 2a, 2b for rotating and moving the moving cam 15, a first mirror 7 for bending the optical path, and a first mirror holder 14 in front of the field frame adjusting frame 3. Incorporate. Further, the field frame adjustment frame 3
Behind the second mirror 8, the second mirror retainer 14a,
A relay lens group 9, an eyepiece moving frame 12 for diopter adjustment incorporating an eyepiece 10, a light-shielding mask 17 at a second real image position,
The fixed stop 18 is incorporated in the relay lens group 9. Finally, the upper finder cover 11 and the side finder cover 13 are attached.

[0018]

As described above, according to the structure of the present invention, the field frame is fixed to one cylindrical lens frame, and a lens system is arranged before and after the field frame. By sealing, it is possible to prevent dust and dirt from entering the visual field frame.

Further, even when the view frame adjusting frame (middle mirror frame) and the main lens barrel of the finder are rubbed during parallax adjustment and dust is generated, no dust enters and adheres to the view frame at all, as in a zoom finder. Since the objective lens needs to be moved, there is no problem even if the viewfinder main barrel has a large opening. Further, the process of attaching the field frame requiring a high degree of cleanliness can be subassembled, so that the assembling workability can be improved.

Furthermore, the field frame adjustment frame is integrally formed with an adjustment portion which also functions as an adjustment guide and positioning in the optical axis direction, a pressurizing portion for adjusting parallax, and an adjustment arm portion. Parallax adjustment can be facilitated.

[Brief description of the drawings]

FIG. 1 is a schematic configuration side view of an embodiment of a finder unit of the present invention.

FIG. 2 is a configuration perspective view of a field frame adjustment frame according to the embodiment of the present invention.

FIG. 3 is a configuration perspective view of a zoom finder unit according to an embodiment of the present invention.

FIG. 4 is a configuration perspective view of a conventional fixed focus finder unit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 finder main lens barrel (main lens barrel) 1a finder main lens barrel side engaging portion 1b finder main lens barrel side receiving arm 2 objective lens group 3 field frame adjustment frame (middle lens frame) 3a field frame adjustment frame convex Joint 3b Field frame adjustment frame pressurizing section 3c Field frame adjustment frame parallax adjustment arm 4 Field frame 5 Viewfinder lens (objective lens) 6 Viewfinder lens (relay lens) 7 Mirror 1 8 Mirror 2 9 Relay lens group 10 Eyepiece Reference Signs List 11 top viewfinder cover 12 eyepiece moving frame 13 side viewfinder cover 14 first mirror holder 14a second mirror holder 15 objective lens moving cam 16

Claims (3)

[Claims] 1. A real image type viewfinder in which a field frame is arranged at a position of a real image of a subject and the real image is magnified by an eyepiece, wherein a viewfinder lens is fixedly arranged at a predetermined position before and after the field frame. A lens frame, at least a finder main lens barrel capable of internally arranging the objective lens system, the middle lens frame, the relay lens system, and the eyepiece system at predetermined positions, and inserting the middle lens frame into the main lens barrel. A real-image finder mechanism characterized by being adjustable. 2. The real image type finder mechanism according to claim 1, wherein the parallax is adjusted by moving the center mirror frame in order to adjust the position of the field frame to correct the parallax. 3. The main lens barrel is positioned and engaged with the main lens barrel in the optical axis direction, and has a convex engaging portion serving as a guide at the time of parallax adjustment. 3. A real image type viewfinder mechanism according to claim 2, further comprising: a pressurizing section for pressurizing the lens barrel, and a parallax adjusting arm having a surface that is in pressure contact with the main lens barrel.