JPH049016A - Finder of camera with built-in long focus zoom lens - Google Patents

Abstract

PURPOSE:To constitute the camera compactly on the whole by incorporating the objective of the finder with a photodetection lens for AF(automatic focusing), and a light measuring element for AF and securing an optical path. CONSTITUTION:A small-aperture part S where center light and marginal light can pass is formed in front of the objective 1, the photodetection lens 3 is arranged almost in level with the surface of the small-aperture part S perpendicular to the optical axis. The objective 1 of the finder, the photodetection lens 3, and light measuring element 18 for AF are incorporated in nesting state. A finder optical system can, therefore, be arranged at the periphery of a photographic lens, specially, above or below. Consequently, even when a long-focus zoom lens is incorporated, the camera which is compact on the whole can be constituted.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a real image finder that includes at least an objective lens of the finder, a light-receiving lens of an optical lens, and an autofocus photometric element f. The present invention relates to a finder belonging to the erector zoom system in which the image magnification can be changed by the movement of the erector, although it is not limited thereto.

[Prior Art] Conventional lens-shutter cameras, especially cameras incorporating a long focal length zoom lens, have a display window for a distance measurement and photometry optical system for autofocus, and a light receiving element for displaying a self-timer. , Strophore light emitting section, remote control light receiving section,
The objective window of the finder and the like are located in what is called the warship section. The space for placing such elements can be determined by increasing the width or height of the warship section, or by installing a split mirror in the viewfinder so that the light for photometry can be collected even if the viewfinder is darkened. is secured.

[Problems to be Solved by the Invention] The conventional finder described in 1) has the characteristics of being relatively simple, but also has various drawbacks.

For example, since it has a warship part, it has the disadvantage of making the camera larger, the parallax of the AF system (autofocus optical system) and finder is large, making it difficult to use, and furthermore, there are problems in that it is difficult to control the quality of the lens. be.

Therefore, an object of the present invention is to provide a real image finder that allows the entire camera to be constructed compactly even though it incorporates a long focal length zoom lens. It is also an object of the present invention to provide a finder that has small parallax, is easy to use, and allows for easy quality control of the entire lens.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes at least an objective lens of a finder, a light receiving lens of an autofocus, and a photometric element of an autofocus, and these are incorporated in a nest. In addition, the light-receiving lens has a surface perpendicular to its optical axis that is substantially concave with a surface perpendicular to the optical axis of a small aperture portion formed in front of the objective lens through which central light and peripheral light can each pass. - arranged so that it is a side.

[Function] As described above, the present invention provides a central light beam in front of the objective lens.
A small aperture through which peripheral light can pass is formed, and the light-receiving lens is arranged to have a substantially concave surface perpendicular to the optical axis of the small aperture, so that the objective lens of the finder,
A light receiving lens and an autofocus photometric element can be nested together.

Therefore, according to the present invention, the finder optical system can be placed around the photographic lens, particularly above and below, and the entire camera can be configured as a compact camera even if a long focus zoom lens is incorporated.

Further, according to the present invention, since the finder optical system can be placed around the photographic lens, the parallax between the AF optical system and the finder can be reduced, and although it is an external finder with a long focal length lens, Easy to use.

In addition, the objective lens of the finder needs to be a lens with a small focal point and a continuous shape in order to make the finder more compact. Since the peripheral light is focused through different parts of the lens, the influence on the image quality is limited to the local precision of each part, and the quality of the lens as a whole is easy to control and relatively easy to manufacture. It is an easy lens.

[Example] One embodiment of the present invention will be described below.

Now, referring to FIG. 1, it can be understood at a glance that according to this embodiment, the finder objective lens 1, the light receiving lens 3, etc. are arranged around the photographing lens 8. This fact will be further understood with reference to FIG. 2 and FIG. That is, finder 1 objective lens 1, AF
light emitting lens 2, AF light receiving lens 3, photometric lens 4,
Self-display LED5. The mechanical button 6 of the window of the first lens adjustment section and the mechanical button 7 of the window of the second lens adjustment section are laid out around the photographing objective lens 8, especially in the upper and lower lens barrels 9 of the photographing objective lens 8, which have a narrow effective optical path. ing.

As shown in FIGS. 4 to 6, the autofocus light-receiving lens 3 includes a block 1 that moves in the optical axis direction.
It is installed in 7. This block 17 includes a finder objective lens 1 and a first field lens 12.
A distance measuring element 18 is also provided, and these elements move in the optical axis direction as a group.

In addition, in the figure, 13a, 13b, and 1.3c are lenses that make up the erector, which are in one block, and are arranged between the second field lens 14 and the second field lens 12 to the wide, middle, and telephoto sides. Each image is tuned and moved so that the position of the image remains constant. In addition, in FIGS. 4 to 6, reference numeral 15 indicates an eyepiece lens, and reference numeral 16 indicates an eyepiece lens.
represent each human eye.

As shown in FIG. 4, a small pattern portion S is formed in front of the objective lens 1 so that the central light and peripheral light intersect. The light-receiving lens 3 is disposed within a substantially concave surface of the small diaphragm S and the optical axis M, which is perpendicular to the optical axis. Further, a distance measuring element 18 is disposed at a position where the AF destination optical path that passes through the light receiving lens 3 is focused, and the objective lens 1 is connected to the light receiving L2.
It is disposed at an intermediate position between the lens 3 and the element 18, where the optical path is narrowed for focusing. With this arrangement, the C1 objective lens 1, the light receiving L/lens, and the distance measuring element 18 can be incorporated into the human body, and can be arranged around the photographic lens 8.

The finder of the above embodiment is a real image finder using a two-degree imaging method, and in particular has an erector that changes the image magnification by moving the erector.
This is called a zoom method, and the camera moves as a unit in accordance with the zooming of the photographic lens 8.

According to this embodiment, there is a viewfinder that has become dog-shaped due to the increase in zoom magnification, above and below the taking lens at the tip of the round lens barrel, which has become larger due to the high magnification, and a hyperfocal point of the taking lens with a focal length of 100 mm or more. A large active type AFF system designed to measure position and distance, a large photometry optical system with a focal length that is extended relative to the size of the photodetector so that it can measure light in a narrow range, and a large photometry optical system that can see far away. The optical system of the display LED, which has become larger in size, has to be arranged, so the upper and lower surfaces of the photographic lens, which have a little extra space, are effectively used due to the screen size.

[Effects of the Invention] According to the present invention, the objective lens of the finder, the light receiving lens of AF, and the photometric element of AF are nested and the optical path is ensured. The large 71-view finder objective lens, AFF optical element, light receiving lens, etc. can be arranged in the limited space of the camera, making the entire camera compact and easy to use.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a front view, FIG. 2 is a side view, FIG. 3 is a plan view, and FIGS. 4, 5, and 6.
The figures show the finder optical system, and Fig. 4 is a formula 49 diagram showing the lens position at wide-angle mode, Fig. 5 at middle-angle mode, and Fig. 6 at telephoto mode. 1... Finder objective/lens 3... AFF optical lens 18... Distance measuring element S...
Small diaphragm part M...plane perpendicular to the optical axis of the small diaphragm part and 4 others

Claims (1)

[Claims] 1. At least includes a finder objective lens, an autofocus light receiving lens, and an autofocus photometric element, which are nested together, and the light receiving lens has a surface perpendicular to its optical axis that is aligned with the objective lens. A zoom lens including a long focal point, characterized in that the zoom lens is arranged so as to be substantially flush with a plane perpendicular to the optical axis of a small aperture formed in front of the lens so that central light and peripheral light can pass therethrough. A camera's real-image viewfinder with a built-in camera.