JPH06102575A - Finder device - Google Patents

Abstract

PURPOSE:To provide a system which is a finder optical system, displays information on a surface suitable for viewing through an eyepiece without placing an optical element and is hardly affected by the dust and soiling of the optical element and simultaneously, the arrangement of the optical system under less restrictions in the arrangement of the optical element. CONSTITUTION:A hologram information display element 5 is arranged in the image forming surface of an objective lens 1 as a position suitable for viewing through the finder optical system or the position away from the conjugate surface of the image forming surface, a hologram is illuminated from the outside of the optical path of the optical system to reproduce the image of the displayed information, so that a member for displaying finder information is not disposed on the image forming surface or its conjugate surface, but a finder information display suitable for the diopter can be executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finder device, and more particularly to information display within a finder field of view in a photographing device such as a camera.

[0002]

2. Description of the Related Art Conventionally, in a finder of a photographing device such as a camera, information for photographing such as a distance measuring mark indicating a distance measuring range is displayed. Many methods of displaying information are known as known techniques, but all of them are vapor-deposited on a transparent member such as glass or acrylic to form a pattern of display information, or wedge-shaped fine prisms. A method such as combining is adopted.

In these prior arts, the pattern plane on which the display information is formed is arranged near the image plane of the objective lens or in the vicinity of its conjugate plane so that the subject image and the display information can be observed at the same time during observation. Is being done. On the other hand, the pattern surface on which the display information is formed is also a surface on which the diopter of the finder optical system is matched.

[0004]

However, in the above-mentioned conventional example, since the information display member is provided at a position where the finder has a diopter matching, when a defect such as dust or dirt is attached to the finder, the finder is displayed. The eyepiece of the optical system plays a role of a loupe, and there is an inconvenience that the defect appears magnified.

In order to eliminate the influence of defects, the optical component should be placed in the vicinity of the image forming plane of the objective lens or its conjugate plane, that is, at a position where the diopter of the finder is matched, rather than in a free space. Was desired, but it was difficult to actually realize.

[0006]

According to the present invention, a hologram information display element is arranged at a position different from the image plane or conjugate plane of the objective lens in the optical path of the finder optical system, and the information display element is arranged as described above. Illuminating from outside the optical path, the display information recorded in the information display element is displayed and reproduced near the position of the image plane or the conjugate plane.

With the structure according to the present invention, even if there is no optical member on the image plane or the conjugate plane, when the observation is carried out by the eyepiece lens in the subsequent finder optical system, the space is observed. The information is displayed as an aerial image. As a result, it is possible to display the finder information with a suitable diopter, without being affected by the defect of the optical member.

[0008]

EXAMPLE 1 FIG. 1 is a schematic view of a main part of an optical system of Example 1 of the present invention. In the figure, reference numeral 1 denotes an objective lens which forms an image of an object on a primary image forming surface S1. Reference numeral 2 is a first field lens, 3 is an erector lens for re-imaging the image formed by the objective lens 1, and 4 is a second field lens. S
Reference numeral 2 is a secondary image plane, and the configuration up to this point is the same as that of the conventional example.

The features of the present invention are as follows: 5 is a transparent hologram information display element, 6 is an eyepiece lens, 7 is an illuminating lens, and 8 is an LED. As shown in the figure, no optical member is arranged in the primary image forming surface S1, the secondary image forming surface S2, and in the vicinity of both.

If there is a surface of the optical member at or near the primary image forming surfaces S1 and S2 or the secondary image forming surface S2, scratches, dust, dirt, etc. on the surface are magnified and observed by the eyepiece lens 6, and When this portion is present in a transparent member such as glass or acrylic, bubbles and dust on the member are also magnified and observed by the eyepiece lens 6. In the system of FIG. 1, this portion is a free space and is not affected by dust, scratches, defects, and the like.

Although there is no optical member in the vicinity of S1 and S2, the information of the finder is displayed by the function of the hologram information display element 5 in the field of view of the finder with the diopter matched. When the light from the LED 8 is incident on the hologram information display element 5 in the system of FIG. 1, the content (display information) recorded on the hologram information display element 5 is displayed as a virtual image at a position corresponding to the secondary imaging surface S2. To be done.

When viewed with the eyepiece lens 6, the display information is displayed in the viewfinder field in a form super-imposed with the image of the object. 2 on the optical axis of the finder optical system
Since the position of the next image plane S2 and the position of the virtual image reproduced from the hologram information display element 5 are coincident with each other, the information in the viewfinder field to be displayed can be observed with the diopter matched.

FIG. 4 is a specific example of display contents in the viewfinder field. In a field of view 24 shown by a rectangle, a mark 22 showing a distance measuring range and a display 23 showing various photographing modes are displayed super-imposed on the image of the object.

FIG. 2 is an explanatory view for explaining the process of making the hologram information display element 5 used in the present invention. In the figure, 30 is a laser light source, 10 is a half mirror for dividing a light beam into a reference light path for photographing a hologram and an object light path, 11, 1
2 is a mirror, 13 and 14 are beam expanders using an objective lens of a microscope, 15 and 16 are pinholes for cleaning the beam shape, and 17 and 18 are collimator lenses. . The light on the object light path side of the shaped laser beam illuminates the mask 19 of display information through transmission, and is then projected on the photosensitive material 5'for recording through the imaging lenses 20 and 21.

The object light that has passed through the mask 19 and the other light split by the half mirror 10 enter the photosensitive material 5'as reference light. Interference fringes are formed by the interference of the two, and recording is performed on the photosensitive material 5 '. The recorded interference fringes are converted into a concavo-convex shape by a known method to form a transmission hologram. The transmissive hologram is set in a mold and can be used as a hologram information display element suitable for mass production depending on the mold. The reproduced image of the mask 19 can be obtained by illuminating the obtained hologram in the same manner as the reference light used for recording.

The position of the reproduced image of the mask 19 in the optical axis direction can be arbitrarily set by shifting the conjugate relationship between the mask 19 and the photosensitive material 5'by a predetermined amount. As can be seen from FIG. 1, the amount to be shifted is a known amount at the time of designing the finder system. By shifting the image forming position of the mask 19 from the position of the photosensitive material 5'by this amount, the position of the image of the reproduced mask 19 is also formed in a space displaced from the surface of the photosensitive material 5 '. Since the size of the display information in the finder field is known in advance, not only the focus position but also the magnification of the mask 19 on the photosensitive material 5'are controlled to desired values.

It is desirable to reproduce the hologram under the same conditions as possible when the hologram is created. In the system of FIG. 1, the light of the LED 8 is also collimated by the illumination lens 7 in correspondence with the collimation of the reference light when the hologram is formed in FIG.

In reality, the hologram is produced by the laser, whereas the reproduction is performed by the LED. If the reproduced image deviates too much from the surface of the photosensitive material 5 ', color misregistration occurs during reproduction, but if the amount of deviation from the photosensitive material 5'is suppressed and a light source with a narrow spectral width such as an LED is used. , The effect of color shift can be ignored.

FIG. 3 is a schematic view of the essential portions of Embodiment 2 of the present invention.
It is a figure which shows the structure of a single-lens reflex camera. 1'is an objective lens, 2'is a field lens, 5'is a transparent hologram information display element, 6'is an eyepiece lens, 7 is a hologram illumination lens, 8 is an LED, 9 is a quick return mirror,
P is a hollow pentagonal dahammyr, and F is a film surface. The object image is formed by the objective lens 1 ′ on the primary image plane S
It is formed at the position of 1 ', and S1' corresponds to the space where the diopter of the eyepiece lens 6 matches. Information display in the finder field is performed at the position S1 ', and the display is performed by the hologram 5 "arranged at a position deviated from S1'.

In this embodiment, the light from the LED 8 is projected on the hologram 5 "through the lens 7 and the quick return mirror 9 to form a reproduced image of the display information at the position S1 '. As a result, the display information is displayed. Is displayed by being super-imposed on the image of the object in the observation visual field.

In this embodiment, the pentagonal dahammer is also made hollow, and no optical element exists near the primary image plane S1 '.

A quick retarder is provided near the primary image forming surface S1 '.
In the area where the reflected light from the mirror 9 and the light going to the eyepiece lens 6 ′ intersect, it is impossible to dispose a conventional information display element in this area.

However, in the case of this embodiment, the display information is S
Since the hologram 5 ″ is imaged at the position 1 ′, not only the position of S1 ′ but also the position of the hologram 5 ″ is out of the region where the optical path is folded and the light rays are commonly present. However, it is possible to alleviate the constraint condition of the optical system design in which the elements cannot be arranged normally.

Further, in FIG. 3, since the position of the primary image forming surface S1 'can enter into the hollow pentagonal dahamra, it is possible to significantly lower the position of the dahamra, and thus the position of the single-lens reflex camera is reduced. Miniaturization can also be realized.

Although only the examples using the transmission type hologram display element have been shown in the above embodiments, the present invention is not limited to this, and a similar system can be constructed by using a reflection type hologram.

[0026]

As described above, according to the present invention, the hologram information display element is arranged at a position distant from the position of the image forming plane of the objective lens or its conjugate plane, which is the position where the diopter of the finder optical system is matched. Then, by using the reproduced image (display information) from the hologram information display element, a finder information display with a diopter is arranged, and a member for finder information display is arranged on the image plane or its conjugate plane. It was possible without a matter. As a result, the effect of significantly reducing the deterioration of the appearance due to dust, dirt, etc. in the finder was achieved.

Further, the projection of the reproduced image by the hologram information display element of the present invention gives a degree of freedom to the arrangement of the optical elements. For example, the combination with the hollow pentagonal mirror shown in FIG. 3 relaxes the restrictions on the arrangement of optical elements caused by complicated overlapping of light rays, and as a result, does not impair the information display function of the finder system, Miniaturization can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic view of a main part showing a configuration of an optical system of Example 1 of the present invention.

FIG. 2 is an explanatory diagram showing a method for manufacturing the hologram information display element according to the first embodiment of the present invention.

FIG. 3 is a schematic view of a main part showing a configuration of a single-lens reflex camera according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of an example of information display in the finder.

[Explanation of symbols]

 1,1 'Objective lens 2,2' Field lens 3 Elector lens 4 Field lens 5,5 "Hologram information display element 5'Holographic recording photosensitive material 6,6 'Eyepiece 7 Lens 8 LED 9 Quick return mirror -10 Half mirror 11,12 Miller 13,14 Microscope objective lens 15,16 Pinhole 17,18 Collimator lens 19 Information display mask 20,21 Lens 22 Display mark indicating the distance measuring range 23 Photographing Display mark indicating mode 24 Field of view of finder 30 Laser

Claims (1)

[Claims] 1. A finder field for observing an image of an object formed by an objective lens with a finder optical system,
In a finder device that displays predetermined display information,
By disposing a hologram information display element at a position away from a position where the diopter of the finder optical system is matched and illuminating the hologram information display element from outside the optical path of the finder optical system, the hologram information display element is obtained. A finder device characterized in that an image of the display information recorded in (1) is reproduced at a position where the diopter matches and the image of the object and the display information are observed.