JP2595732Y2 - Real-image finder device with near-field correction mark - Google Patents

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 viewfinder, and more particularly to a real image type viewfinder having a near field correction mark for parallax correction at the time of close range photographing.

[0002]

2. Description of the Related Art Conventionally, a real image type finder in which an inverted image formed by a positive objective lens group and a positive condenser lens group is erected by an erecting optical system and observed by a positive eyepiece lens group. It has been known. In a camera provided with this real image type finder, a near field correction mark is generally provided in the finder field for parallax correction at the time of short distance shooting. Conventionally, the near-field correction mark is provided on a focusing plate arranged at an image forming position of an object at a specific distance.

[0003] The eyepiece of a finder usually has a diopter of-for a subject at a finite distance (generally 3 m to 5 m).
It is set to 0.5 to -1D (diopter). For this reason, in the above-described conventional real-image finder having a short-distance correction mark on the focus plate, the subject image is formed closer to the eye than the focus plate during short-distance shooting. And a diopter difference occurs between the subject image and the near-field correction mark, so that the subject image and the near-field correction mark cannot be seen at the same time.
It was very unsightly.

Further, in the conventional real image type finder, when photographing when the subject is located at a long distance, the short-range visual field correction mark is clearly observed in the finder visual field even though it is unnecessary. Therefore, the short-range visual field correction mark was a hindrance in the finder visual field.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and provides a real image type finder in which a near field correction mark used for short distance photographing is easy to see in a finder field. With the goal.

[0006]

SUMMARY OF THE INVENTION The present invention comprises an objective optical system for forming a real image of an object image, an eyepiece optical system for observing a real image by the objective optical system, and further has a near-field correction mark in the visual field. In the real image type finder device, the near field correction mark is provided on a surface of an optical element located closer to an eye than a position where an image is formed by the objective optical system.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on illustrated embodiments. FIG. 2 shows a lens configuration of a real image type finder optical system to which the present invention is applied, which is provided in a lens shutter type camera. This real image type viewfinder optical system includes a positive objective lens group 11, a positive condenser lens group 1 from the object side.
2, an erecting optical system 18 and a positive eyepiece lens group 19 are provided. The objective lens group 11 includes a movable negative lens group 1
This is a variable power objective lens group consisting of 1n and a positive lens group 11p. The erecting optical system 18 has a known configuration including a Porro prism and the like.

The condenser lens group 12 and the erecting optical system 18
A focusing plate 20 is provided between the two. The focus plate 20 is made of a transparent glass or acrylic plate, and has a field frame 21 on its object-side surface, which shows a shooting range at the time of shooting when the subject is not located at a short distance.
The focus frame 22 is drawn at the center thereof (FIG. 1).

The erecting optical system 18 is configured such that the incident surface 18a facing the focusing plate 20 located on the object side is a convex curved surface. A short-range visual field correction mark 23 for parallax correction during short-range imaging is drawn on the incident surface 18a. FIG. 3 shows a finder visual field observed when looking into the real image type finder optical system of the present embodiment. The present invention provides a near field correction mark 23.
Is formed on the surface of the optical element located closer to the eye than the image forming position (the position where the focusing plate 20 is provided) by the objective optical system, that is, on the surface of the entrance surface 18a of the erecting optical system 18 in this embodiment. Has features.

In a conventional real-image finder having a short-distance correction mark on a focus plate, the subject image is formed closer to the eye than the focus plate during short-distance shooting. The diopter with the subject image did not match, and when shooting at a long distance, unnecessary short-range vision correction marks were clearly observed in the viewfinder visual field, making the viewfinder visual field very difficult to see. According to the real image type finder according to the present invention, the near field correction mark 23 is formed closer to the eye than the focus plate 20. Near field correction mark 2 because distance field correction mark 23 is close
3 and the subject image are easily observed at the same time. Further, at the time of long-distance shooting, the near-field correction mark 23 in the finder field is blurred and not matched with the diopter of the subject image, so that the subject image is easily observed. Become.

In this embodiment, the real image type finder has been described with reference to a real image type finder having a zooming function. However, the present invention is not limited to this, and may be applied to a real image type finder having no zooming function.

In this embodiment, the near-field correction mark is formed on the surface of the entrance surface 18a of the erecting optical system 18. However, the present invention is not limited to this. It may be formed on the surface of an optical element located closer to the eye than the position where an image is formed by the objective optical system, for example, formed on a surface of a newly provided transparent plate.

[0013]

As described above, according to the real image type finder device having the near field correction mark of the present invention, the near field correction mark is positioned closer to the eye than the image forming position by the objective optical system. With this simple configuration, it is possible to provide a real image type finder in which the near field correction mark used for short distance shooting is easy to see in the finder field.

[Brief description of the drawings]

FIG. 1 is a view showing a real image type finder optical system according to the present invention.

FIG. 2 is an enlarged view of a main part according to the present invention of FIG.

FIG. 3 is a view showing a finder visual field;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Objective lens group 12 Condenser lens group 18 Erect optical system 19 Eyepiece lens group 20 Focus board 21 Field frame 22 Focus frame 23 Short-range field correction frame

Claims (2)

(57) [Scope of request for utility model registration] An objective optical system for forming a real image of an object image,
An eyepiece optical system for observing a real image by the objective optical system, further comprising: a real-field finder device having a near-field correction mark in a visual field, wherein the near-field correction mark is formed by the objective optical system. A real-image finder device having a near-field correction mark, which is attached to the surface of an optical element located closer to the eye than the position. 2. The real-image finder according to claim 1, further comprising a near-field correction mark provided with a field frame indicating a normal shooting range at an image forming position by the objective optical system.