JPH1096981A - Real image finder - Google Patents

Abstract

(57) [Summary] [Problem] To correct parallax not only by subject distance but also by focal length change, and to appropriately correct the parallax according to the size by a simple configuration with a small number of parts. SOLUTION: An object light beam having passed through an objective lens system 1 has a light path deflected by a first reflection surface 2a and a second reflection surface 2b of a first prism 2, and passes through a field mask 3. The subject luminous flux that has passed through the field mask 3 is
First reflecting surface 4a and second reflecting surface 4 of prism 4
The light path is further deflected by b to reach the eyepiece lens system 5. The first prism 2 is driven by the prism driving device 11 according to the subject distance information from the subject distance detecting device 9 or the subject focal distance information and the zoom focal length information from the zoom focal length detecting device 10. Reflective surface 2
It is moved along the optical axis direction (vertical direction) after being deflected by a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to parallax correction of a real image type finder in a camera having different optical axes of a photographic lens system and a finder lens system, and more particularly to a finder lens system interlocked with a photographic lens system such as a zoom lens. The present invention relates to a real image type finder suitable for a zoom finder capable of changing a focal length of the zoom lens.

[0002]

2. Description of the Related Art In a so-called lens shutter camera, since a finder lens system is generally provided separately from a photographic lens system, an optical axis of the photographic lens system is different from an optical axis of the finder lens system. As described above, even if the optical axis of the photographing lens system and the optical axis of the finder lens system are different, there is no particular problem for an extremely distant subject such as infinity. However, if the optical axis of the photographic lens system is different from the optical axis of the finder lens system for an object at a short distance, the photographic center and the viewfinder center will be displaced. Such a shift in the visual field is called parallax (parallax).

In particular, in a lens shutter camera with a zoom lens using a zoom lens as a photographing lens system, parallax on the film surface varies depending on the focal length, and parallax increases on the long focal length side. On the focal length side, parallax correction technology used in single focus cameras cannot sufficiently correct. Therefore, a parallax correction technique capable of coping with a change in the focal length is required. For example, Japanese Unexamined Patent Publication No.
No. 32 and JP-A-4-114113,
In a real image type finder using an erecting normal image optical system using a Porro prism, a mirror or a prism configuring a first reflecting surface of the Porro prism is moved in an optical axis direction according to focal length information and / or subject distance information. To correct parallax in the zoom finder.

[0004]

As described above, as described above, Japanese Patent Application Laid-Open Nos. Hei 4-251232 and Hei 4-11411 are disclosed.
In the real image type finder disclosed in Japanese Patent Application Publication No. 3 (1993) -1994, a real image type finder is formed by using a porro prism in the erecting normal image optical system, and the first reflecting surface of the porro prism is formed by a mirror or a prism, The first Porro prism according to the information and / or the subject distance information.
By moving the mirror or prism constituting the reflection surface in the optical axis direction to correct the parallax, it is possible to correspond to a zoom lens.

However, in the configuration of the real image type finder disclosed in JP-A-4-251232 and JP-A-4-114113, a Porro prism is used, and a mirror or a prism which is a part of the Porro prism is made movable. Configuration, the configuration becomes complicated, and in effect,
There is a problem that the number of parts increases. The present invention has been made in view of the above circumstances, and a first object of the present invention is to
An object of the present invention is to provide a real image type finder that can appropriately correct parallax according to the size of parallax and has a simple configuration with a small number of parts and can cope with a change in focal length.

A second object of the present invention is to provide a real image type finder capable of adjusting a parallax correction amount with a small number of parts. A third object of the present invention is to provide a real image type finder capable of appropriately correcting parallax according to a subject distance. A fourth object of the present invention is to provide a real image type finder capable of appropriately correcting parallax according to a subject distance and a focal length.

A fifth object of the present invention is to provide a real image type finder capable of adjusting a parallax correction amount and a finder diopter with a small number of parts. A sixth object of the present invention is to provide a real image type finder capable of appropriately correcting parallax according to a subject distance and correcting finder diopter. A seventh object of the present invention is to provide a real image type finder capable of appropriately correcting parallax according to a subject distance and a focal length and correcting a finder diopter.

[0008]

According to a first aspect of the present invention, there is provided a real image type finder having a positive refracting power and an object disposed on the object side in order to achieve the first object. A lens, a field mask disposed near a focal plane of the objective lens, an eyepiece for observing an object image formed on the focal plane of the objective lens, and an eyepiece for the objective lens and the objective lens. A first reflecting means disposed in an optical path between the focal plane and the two reflecting surfaces, and a first reflecting means disposed in an optical path between the focal plane and the eyepiece of the objective lens; A second reflecting means having a surface; and a driving means for moving at least one of the first reflecting means, the field mask and the second reflecting means to correct parallax. I have.

According to a second aspect of the present invention, there is provided a real image type finder according to the first aspect, wherein the first reflecting means is provided to achieve the first and second objects. Incident surface of the first reflecting surface of
The exit surface of the second reflection surface of the reflection means is located in the same plane, and the entrance surface of the first reflection surface of the second reflection means and the second reflection surface of the second reflection means Are located in the same plane, and the planes of the first and second reflecting means are arranged parallel to each other and shifted from each other by 90 °.

According to a third aspect of the present invention, there is provided a real image type finder according to the present invention, wherein the driving means comprises an object. According to another aspect of the present invention, the apparatus further includes means for moving the first reflecting means in an optical axis direction after being deflected by the first reflecting surface of the first reflecting means according to the distance information.

According to a fourth aspect of the present invention, there is provided a real image type finder according to the present invention, wherein the first, second and fourth objects are achieved. Includes means for moving the first reflecting means in the optical axis direction after being deflected by the first reflecting surface of the first reflecting means in accordance with subject distance information and focal distance information. It is characterized by.

According to a fifth aspect of the present invention, there is provided a real image type finder according to the first aspect of the present invention, wherein the first reflecting means is provided to achieve the first and fifth objects. The incidence surface of the first reflection surface and the emission surface of the second reflection surface of the first reflection means are orthogonal to each other, and the incidence surface of the first reflection surface of the second reflection means and the second reflection surface The exit surfaces of the second reflection surface of the reflection unit are orthogonal to each other, and the exit surfaces of the first reflection surface of the first reflection unit and the second reflection surface of the second reflection unit are perpendicular to each other. Surfaces are parallel to each other, and the exit surface of the second reflection surface of the first reflection unit and the incidence surface of the first reflection surface of the second reflection unit are parallel to each other. I have.

According to a sixth aspect of the present invention, there is provided a real image type finder according to the fifth aspect of the present invention, wherein the first, fifth and sixth objects are achieved. Is characterized by including means for moving the first reflecting means in the direction of the incident optical axis of the first reflecting surface of the first reflecting means according to subject distance information.

According to a seventh aspect of the present invention, there is provided a real image type finder according to the fifth aspect of the present invention, in order to achieve the first, fifth and seventh objects. Is characterized by including means for moving the first reflecting means in the direction of the incident optical axis of the first reflecting surface of the first reflecting means according to the subject distance information and the focal distance information.

[0015]

The real-image finder according to the first aspect of the present invention comprises, sequentially from the object side, an objective lens having a positive refractive power, a field mask disposed near a focal plane of the objective lens, and the objective lens of the objective lens. A first reflecting means having an eyepiece for observing an object image formed on a focal plane and having two reflecting surfaces in an optical path between the objective lens and the focal plane of the objective lens; And a second reflection unit having two reflection surfaces in an optical path between the focal plane of the objective lens and the eyepiece, and the first reflection unit, the field mask, and the second reflection unit. At least one of the reflection means is moved to correct parallax.

With this configuration, parallax can be properly corrected by moving at least one of the first reflecting means, the field mask, and the second reflecting means. The parallax can be properly corrected by adjusting the correction amount according to the size of the parallax with a simple configuration having few parallaxes. Further, in the real image type finder according to claim 2 of the present invention, the entrance surface of the first reflection surface of the first reflection unit and the exit surface of the second reflection surface of the first reflection unit are in the same plane. And the entrance surface of the first reflection surface of the second reflection unit and the exit surface of the second reflection surface of the second reflection unit are located on the same plane, and the first and second reflection units are located on the same plane. The planes of the second reflecting means are arranged in parallel with each other and shifted from each other by 90 °.

According to such a configuration, the first and second reflecting means can be made a common configuration, and the amount of parallax correction can be appropriately adjusted with a small number of parts. According to a third aspect of the present invention, in the real image type finder, after the driving means has turned the first reflecting means by the first reflecting surface of the first reflecting means according to the subject distance information. And means for moving in the optical axis direction. With such a configuration, the first reflection unit is driven according to the subject distance, so that the parallax can be appropriately corrected according to the subject distance.

According to a fourth aspect of the present invention, in the real image type finder, the driving means controls the first reflecting means according to the subject distance information and the focal length information. It is configured to include a means for moving in the optical axis direction after being turned by the surface. With such a configuration, the first reflection unit is driven according to the subject distance and the focal length, so that the parallax can be appropriately corrected according to the subject distance and the focal length.

In a real image type finder according to a fifth aspect of the present invention, the entrance surface of the first reflection surface of the first reflection unit and the exit surface of the second reflection surface of the first reflection unit are orthogonal to each other. In addition, the entrance surface of the first reflection surface of the second reflection unit and the exit surface of the second reflection surface of the second reflection unit are perpendicular to each other, and the first reflection surface of the first reflection unit. The incident surface of the reflecting surface and the exit surface of the second reflecting surface of the second reflecting means are parallel to each other, and the exit surface of the second reflecting surface of the first reflecting means and the second reflecting surface. The first reflecting surface of the reflecting means is parallel to the incident surface.

With such a configuration, the first and second reflecting means can be made a common configuration, and the parallax correction amount and the finder diopter can be appropriately adjusted with a small number of parts. Become. In a real image type finder according to claim 6 of the present invention, the driving means shifts the first reflecting means in a direction of an incident optical axis of a first reflecting surface of the first reflecting means according to subject distance information. It is configured to include means for moving. With such a configuration, the first reflection unit is driven according to the subject distance, so that it is possible to appropriately correct parallax according to the subject distance and to correct the finder diopter.

According to a seventh aspect of the present invention, in the real image type finder, the driving means controls the first reflecting means according to the subject distance information and the focal length information. It is configured to include means for moving the surface in the direction of the incident optical axis. With such a configuration, the first reflection unit is driven according to the subject distance and the focal length, so that the parallax is appropriately corrected according to the subject distance and the focal length, and the finder diopter is corrected. Becomes possible.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A real image type finder according to the present invention will be described below in detail based on embodiments with reference to the drawings. FIGS. 1 and 2 show a configuration of a main part of a first embodiment of a camera incorporating a real image type finder according to the present invention. FIG. 1 is a block diagram showing a schematic configuration of a main part of a camera including an arrangement of a real image type finder and an optical system of a photographing lens system according to this embodiment.
FIG. 3 is a perspective view showing a detailed configuration of the real image type finder portion.

The camera shown in FIG. 1 has an objective lens system 1, a first prism 2 as first reflecting means, a field mask 3, a second prism 4 as second reflecting means, an eyepiece lens system 5, Operating member 6, drive motor 7, photographing lens system 8, subject distance detecting device 9, zoom focal length detecting device 1
0 and a prism driving device 11. The real-image finder according to this embodiment includes an objective lens system 1,
A first prism 2, a field mask 3, a second prism 4,
It comprises an eyepiece system 5, an operating member 6, and a drive motor 7, and its detailed configuration is shown in FIG.

The objective lens system 1 has a positive refractive power, is arranged on the object side, that is, on the object side, and forms an object image. The objective lens system 1 has an objective system first group lens 1A and an objective system second group lens 1B, and these objective system first group lens 1A and objective system second group lens 1A.
By relatively moving B along the optical axis direction, the focal length changes. The first prism 2 and the second prism 4 perform image inversion for obtaining an erect erect image as a viewfinder observation image.

The first prism 2 is a right-angle prism constituting the first reflecting means, and has a first reflecting surface 2a and a second reflecting surface 2b. The first reflecting surface 2a is positioned at a distance of 4 with respect to the optical axis of the subject light beam incident through the objective lens system 1.
It is inclined by 5 °, and reflects the subject light flux to turn it by 90 °. The second reflecting surface 2b, which forms a right-angle prism orthogonal to the first reflecting surface 2a, is inclined at 45 ° in the same direction with respect to the optical axis of the light beam reflected and diverted by the first reflecting surface 2a. And further turns the light beam in the same direction by 90 °. Therefore, the first prism 2 is connected to the objective lens system 1
A light beam that is incident on the subject through a light beam is emitted in a direction parallel to the optical axis and at a different angle of 180 ° at a position shifted by a predetermined distance in a direction orthogonal to the optical axis of the light beam.

The second prism 4 is a right-angle prism constituting a second reflecting means, and has a first reflecting surface 4a and a second reflecting surface 4b. The first reflection surface 4a is at an angle of 45 ° with respect to the optical axis of the light beam incident through the first prism 2.
It is inclined and reflects the light beam to turn it by 90 °.
The second reflecting surface 4b, which forms a right-angle prism orthogonal to the first reflecting surface 4a, is inclined at 45 ° in the same direction with respect to the optical axis of the light beam reflected and diverted by the first reflecting surface 4a. And further turns the light beam in the same direction by 90 °.

Therefore, the second prism 4 shifts the subject light beam incident via the first prism 2 at a position shifted by a predetermined distance in a direction orthogonal to the optical axis of the light beam and parallel to the optical axis. Inject in 180 ° different directions. That is, as shown in FIG. 2, the entrance surface of the first reflecting surface 2a of the first prism 2 and the exit surface of the second reflecting surface 2b of the first prism 2 are located on the same plane. ing. Also,
The incident surface of the first reflecting surface 4a of the second prism 4 and the second
And the exit surface of the second reflection surface 4b of the prism 4 are located on the same plane.

Further, as shown in FIGS. 2 and 3, the incident surface of the first reflecting surface 2a of the first prism 2 and the second
A plane including the exit surface of the reflection surface 2b of the second prism 4
And the plane including the entrance surface of the first reflection surface 4a and the exit surface of the second reflection surface 4b are from the second reflection surface 2b of the first prism 2 to the first reflection surface of the second prism 4. The first prism 2 and the second prism 4 are arranged so as to be orthogonal to each other on a straight line including the optical axis reaching 4a. In other words, the planes of the first and second reflecting prisms 2 and 4 are parallel to each other, and the first and second prisms 2 and 4 are relatively shifted by 90 ° (rotated by 90 °). ) Is arranged.

FIG. 3 is a front view showing an example of arrangement of the photographing lens system 8 and the real image type finder system when viewed from the front side of the camera. In this case, as shown in FIG. 3, the objective lens system 1 of the real image type finder system is disposed above the photographing lens system 8, and the optical axis of the objective lens system 1 of the real image type finder system is 8 is located directly above the optical axis. A subject image formed by the objective lens system 1 forms an image on a focal plane on an optical path between the first prism 2 and the second prism 4, and determines a visual field in a viewfinder observation image on an optical path near the focal plane. A visual field mask 3 is arranged.

The eyepiece lens system 5 is an optical system for observing a subject image (real image) formed near the field mask 3 within the field of view of the field mask 3. Note that the field mask 3 does not limit the finder observation field to the imaging field, and may display a field image indicating the imaging field by overlapping the finder observation image including the periphery of the imaging field. The operating member 6 includes a rack portion 6a that extends in parallel with the optical axis of the light beam reflected by the first reflecting surface 2a of the first prism 2 when the light beam of the object incident through the objective lens system 1 is reflected.
Having.

The motor 7 has a pinion 7 a fixed to its rotating shaft, and the pinion 7 a meshes with the rack 6 a of the operating member 6. The motor 7 is driven by the prism driving device 11 shown in FIG. 1 to move the first prism 2 along the optical axis of the light beam reflected and diverted by the first reflection surface 1a. The taking lens system 8 forms a subject image on an image recording medium (not shown), for example, a silver halide film, and records the subject image.

It is to be noted that an optical image of a subject is formed by an imaging lens system 8 on an image pickup device such as a CCD (charge coupled device) solid-state image pickup device instead of the image recording medium, and the image pickup device
The subject optical image is converted into electronic subject image information, and P
C card, that is, PCMCIA (Personal Computer)
The subject image information may be recorded on an electronic recording medium such as an IC (integrated circuit) memory card or a video floppy according to the Memory Card International Association) standard.

The photographing lens system 8 is configured as a zoom lens in this case, and can change the focal length by a zooming operation by the photographer. In addition, focusing of the subject image according to the subject distance, that is, focusing adjustment,
This is performed by moving the entire photographing lens system 8 along the optical axis in accordance with a manual operation by a photographer or an automatic operation by an autofocus control device (not shown).
The subject distance detection device 9 detects subject distance information in connection with a distance adjustment operation (focusing operation) by a photographer operating a distance ring (not shown) or the like or a distance adjustment by an autofocus control device. , To the prism driving device 11.

The zoom focal length detecting device 10 is associated with a zooming operation by a photographer operating a zoom ring (not shown) or the like or a zooming operation by an electric zooming control device (not shown). The distance information is detected and given to the prism driving device 11.
The prism driving device 11 operates the motor 7 in accordance with the subject distance information from the subject distance detection device 9 or the zoom distance information from the zoom distance detection device 10. , The first prism 2 is operated along the optical axis of the luminous flux reflected and diverted by the first reflecting surface 2a to correct parallax. Therefore, the driving means for driving the first prism 2 is mainly constituted by the prism driving device 11, which includes the operating member 6, the motor 7, the subject distance detecting device 9, and the zoom focal length detecting device. 10
Is also included.

Next, the operation of the camera having the real image type finder thus constructed will be described in more detail. The light from the subject is transmitted to the objective first group lens 1A.
Then, the light enters the objective lens system 1 having a two-group configuration including the objective second lens unit 1B. The light beam of the subject that has passed through the objective lens system 1 passes through the field mask 3 after the optical path is deflected by the first reflection surface 2 a and the second reflection surface 2 b of the first prism 2. The light path of the subject light beam that has passed through the field mask 3 is further deflected by the first reflection surface 4a and the second reflection surface 4b of the second prism 4, and reaches the eyepiece lens system 5. In the vicinity of the field mask 3, a real image of the subject is formed, and the subject image passes through the field mask 3 and is observed through the eyepiece lens system 5.

Objective first lens unit 1A of objective lens system 1
The objective second lens unit 1B moves in the optical axis direction in conjunction with zooming of the photographing lens system 8, and the focal length changes. The first prism 2 of the first prism 2 and the second prism 4 that perform image inversion for obtaining an erect image is provided with subject distance information from the subject distance detection device 9,
Alternatively, according to the subject distance information and the zoom focal length information from the zoom focal length detecting device 10, the prism driving device 11 moves the optical disc along the optical axis direction after being deflected by the first reflecting surface 2a. You. The movement of the first prism 2 by the prism driving device 11 corrects parallax between the finder optical system and the photographing lens system 8 according to the subject distance or the subject distance and the zoom focal length.

Referring to FIGS. 4 and 5, FIG.
The operation of the real image type zoom finder shown in FIGS. As described above, the objective lens system 1 of the real image type finder system is disposed above the taking lens system 8, and the optical axis of the objective lens system 1 of the real image type finder system is the same as the optical axis of the taking lens system 8. The description will be made assuming that it is located directly above (see FIG. 3). In the case of the conventional real-image finder without parallax correction, when the subject on the incident optical axis of the finder optical system has a very long subject distance, that is, when the subject is at infinity, the subject image appears at the center of the visual field.

At this time, even in the image taken by the taking lens system 8, the subject image is taken such that the subject image is located at the center of the taking picture. However, when the subject distance is short, the subject image is shifted from the center of the photographing screen as shown in FIG. Therefore, in the real image type viewfinder of this embodiment, the erect erect image optical system of the viewfinder is composed of the first prism 2 and the second prism 4, and the first prism 2 is connected to the object distance detecting device 9
In accordance with the subject distance information from the camera or the subject distance information and the zoom focal length information from the zoom focal length detecting device 10, the optical axis after being turned by the first reflecting surface 2a as shown in FIG. Along the direction, it is moved downward in the figure, that is, in the direction A in the figure.

Therefore, the image in the field mask 3 is shown in FIG.
Moves from the position B to the position C, and the same object arrangement as that of the screen actually shot is viewed as a finder image, and parallax is corrected. As described above, the parallax generated based on the subject distance or the subject distance and the zoom focal length can be appropriately corrected according to the magnitude. Further, since the first prism 2 as the first reflecting means and the second prism 4 as the second reflecting means have the same shape, they can be used as common parts, and the number of parts can be reduced. Can be.

Instead of correcting the parallax by moving the first prism 2, the second prism 4 or the field mask 3 may be moved, and the first prism 2 and the field mask 3 may be moved. And the second prism 4
Two or more of them may be moved in a complex manner. FIGS. 6 and 7 show a configuration of a main part of a second embodiment of a camera incorporating a real image type finder according to the present invention. FIG. 6 is a block diagram showing a schematic configuration of a main part of a camera including an arrangement of a real image finder and an optical system of a photographing lens system according to this embodiment.
FIG. 3 is a perspective view showing a detailed configuration of the real image type finder portion.

The camera shown in FIG.
First prism 22, field mask 23, second prism 24, eyepiece system 25, operating member 26, drive motor 2
7, a photographing lens system 28, a subject distance detecting device 29, a zoom focal length detecting device 30, and a prism driving device 31. These are an objective lens system 21, a first prism 22, a field mask 23, a second prism 24, an eyepiece system 25, an operating member 26, a drive motor 27, a photographing lens system 28, a subject distance detection device 29, a zoom focal length. The detection device 30 and the prism driving device 31 are respectively the objective lens system 1, the first prism 2, the field mask 3, the second prism 4, the eyepiece lens system 5, the operating member 6, and the driving motor shown in FIG. 7, a photographing lens system 8, a subject distance detecting device 9, a zoom focal length detecting device 10, and a prism driving device 11.

The real image type finder according to this embodiment includes an objective lens system 21, a first prism 22, a field mask 23, a second prism 24, an eyepiece system 25, an operating member 26, and a drive motor 27. The detailed configuration is shown in FIG. The objective lens system 21 has a positive refractive power, is arranged on the object side, that is, on the subject side, and forms a subject image. The objective lens system 21 has an objective first lens group 21A and an objective second lens group 21B. The objective first lens group 21A and the objective second lens group 21B are arranged along the optical axis direction. , The focal length changes.

The first prism 22 and the second prism 24 perform image inversion for obtaining an erect erect image as a viewfinder observation image. The first prism 22 is a prism constituting a first reflection unit, and has a first reflection surface 22a and a second reflection surface 22b. The first reflection surface 22a is
It is inclined by 45 ° with respect to a plane orthogonal to the optical axis of the subject light beam incident through the objective lens system 21, reflects the subject light beam, and turns it 90 ° to the left (when viewed from the front). . The second reflection surface 22b is inclined by 45 ° with respect to a plane orthogonal to the optical axis reflected and diverted by the first reflection surface 22a, and the light flux reflected and diverted by the first reflection surface 22a. The optical axis is turned upward by 90 °.

Therefore, the first prism 22 shifts the subject light beam incident through the objective lens system 21 by a predetermined distance in a direction (lateral direction) orthogonal to the optical axis of the light beam. The light is emitted in a direction different from the optical axis and a direction orthogonal thereto by 90 °. The second prism 24 is a prism constituting a second reflection unit,
It has a first reflecting surface 24a and a second reflecting surface 24b. The first reflection surface 24a is inclined by 45 ° with respect to a plane orthogonal to the optical axis of the light beam incident through the first prism 22, reflects the light beam, and turns 90 ° rightward. Let it.

The second reflecting surface 22b is provided with a first reflecting surface 24.
4 with respect to a plane perpendicular to the optical axis
The optical axis of the luminous flux reflected and diverted by the first reflection surface 24a is diverted by 90 ° backward. Therefore, the second prism 24 shifts the subject light beam incident via the first prism 22 at a position shifted by a predetermined distance in the direction orthogonal to the optical axis of the light beam with respect to the optical axis and the direction orthogonal thereto. In 90 ° different directions. That is, as shown in FIG.
Of the first reflecting surface 22a and the second surface of the first prism 22
Are perpendicular to the exit surface of the reflection surface 22b. The incident surface of the first reflecting surface 24a of the second prism 24 and the exit surface of the second reflecting surface 24b of the second prism 24 are orthogonal to each other.

Further, as shown in FIGS. 7 and 8, the entrance surface of the first reflection surface 22a of the first prism 22 and the exit surface of the second reflection surface 24b of the second prism 24
The first reflecting surface 22b of the first prism 22 and the exit surface of the first reflecting surface 24a of the second prism 24 are parallel to each other, and the first reflecting surface 24a is parallel to each other. And the second prism 24 are disposed. In this case, since the emission optical axis of the second reflection surface 22b of the first prism 22 and the incident optical axis of the first reflection surface 24a of the second prism 24 are substantially common, the first prism 22 The exit surface of the second reflection surface 22b and the entrance surface of the first reflection surface 24a of the second prism 24 are located on the same plane.

FIG. 8 is a front view showing an example of arrangement of the photographing lens system 28 and the real image type finder system when viewed from the front side of the camera. In this case, as shown in FIG. 8, the objective lens system 21 of the real image type finder system is
8, the optical axis of the objective lens system 21 of the real image type finder system is located right beside the optical axis of the photographing lens system 28, that is, in the horizontal direction. Objective lens system 2
1 forms an image on a focal plane on the optical path between the first prism 22 and the second prism 24, and on the optical path near the focal plane, determines a field of view in the viewfinder observation image. 23 are arranged.

The eyepiece lens system 25 is an optical system for observing a subject image formed near the field mask 23 within the field of view of the field mask 23. The field mask 23 does not limit the finder observation field to the imaging field, but may display a field image indicating the imaging field by being superimposed on the finder observation image including the periphery of the imaging field. The operating member 26 has a rack 26a extending in parallel with the optical axis of the subject light beam incident on the first prism 22 via the objective lens system 21. The motor 27 has a pinion 27a fixed to its rotating shaft.
7a is meshed with the rack 26a of the operating member 26.

The motor 27 is driven by the prism driving device 31 to move the first prism 22 to the objective lens system 2.
The light beam is moved along the optical axis of the subject light beam guided by 1. The taking lens system 28 forms a subject image on an image recording medium (not shown), for example, a silver halide film, and records the subject image. Note that instead of an image recording medium, a CCD
A subject optical image is formed by an imaging lens system 8 on an imaging device such as a solid-state imaging device, and the imaging device converts the subject optical image into electronic subject image information, and converts the subject optical image into an electronic image such as a PC card or a video floppy. The subject image information may be recorded on an objective recording medium.

The photographing lens system 28 is configured as a zoom lens in this case, and can change the focal length by a zooming operation by the photographer. Focusing of the subject image in accordance with the subject distance, that is, focusing adjustment, is performed by moving the entire photographic lens system 8 along the optical axis according to a manual operation by a photographer or an automatic operation by an autofocus control device (not shown). By moving along. The subject distance detecting device 29 detects subject distance information in connection with a distance adjustment operation by a photographer by operating a distance ring (not shown) or the like or a distance adjustment by an autofocus control device, and a prism driving device 31. Give to.

The zoom focal length detecting device 30 is associated with a zooming operation by a photographer operating a zoom ring (not shown) or the like or a zooming operation by an electric zooming control device (not shown). The distance information is detected and given to the prism driving device 31.
The prism driving device 31 operates the motor 27 in response to the subject distance information from the subject distance detecting device 29 or the subject distance information and the zoom focal length information from the zoom focal length detecting device 30, and the operating member 26 Through the first prism 22 from the objective lens system 21 to the first prism.
Is operated along the optical axis of the subject light beam incident on the prism 22 to correct the parallax.

At this time, the parallax can be similarly corrected by operating the first prism along the optical axis of the light beam reflected and diverted by the first reflection surface 22a. Therefore, the driving means for driving the first prism 22 is mainly constituted by the prism driving device 31, and the driving means includes an operating member 26, a motor 27, a subject distance detecting device 29, and a zoom focal length detecting device. 30 is also included.

Next, the operation of the camera having the real image type finder thus constructed will be described in more detail. The light from the subject is transmitted to the objective first group lens 21.
The light enters the objective lens system 21 having a two-group configuration of A and the objective system second group lens 21B. The light beam of the subject that has passed through the objective lens system 21 is deflected by the first reflection surface 22a and the second reflection surface 22b of the first prism 22, and passes through the field mask 23. The light path of the subject light beam that has passed through the field mask 23 is further deflected by the first reflection surface 24a and the second reflection surface 24b of the second prism 24, and reaches the eyepiece lens system 25. Field mask 23
, A real image of the subject is formed, and the subject image passes through the field mask 23 and is observed through the eyepiece lens system 25.

Objective system first group lens 2 of objective lens system 21
1A and the objective system second group lens 21B
Moves in the direction of the optical axis in conjunction with zooming, and the focal length changes. The first prism 22 of the first prism 22 and the second prism 24 that perform image reversal to obtain an erect image is provided with the subject distance information from the subject distance detection device 29 or the subject distance. According to the information and the zoom focal length information from the zoom focal length detecting device 30, the prism driving device 31 causes the objective lens system 21
Is moved along the optical axis direction of the subject light beam.

The movement of the first prism 22 by the prism driving device 31 corrects parallax between the finder optical system and the photographing lens system 28 according to the subject distance or the subject distance and the zoom focal length. .
Note that parallax can be similarly corrected by moving the first prism 22 along the optical axis direction after being deflected by the first reflection surface 2a. Further, the operation of the real image type zoom finder shown in FIGS. 6 to 8 will be described with reference to FIGS.

As described above, the objective lens system 21 of the real image type finder system is disposed beside the taking lens system 28, and the optical axis of the objective lens system 21 of the real image type finder system is
It is located right beside the optical axis of the taking lens system 28 (FIG. 8,
(See FIG. 10). In the case of the conventional real-image finder without parallax correction, when the subject on the incident optical axis of the finder optical system has a very long subject distance, that is, when the subject is at infinity, the subject image appears at the center of the visual field. At this time, even in the image taken by the taking lens system 28, the subject image is taken such that the subject image is located at the center of the taking screen.

However, when the subject distance is short,
Although the image in the viewfinder looks at the center, in the captured image, the subject image is shifted from the center of the captured image as shown in FIG. Thus, in the real image type finder of this embodiment, the erect erect image optical system of the finder is constituted by the first prism 22 and the second prism 24, and the first prism 22 is connected to the object distance detecting device 29.
According to the subject distance information from the camera or the subject distance information and the zoom focal length information from the zoom focal length detecting device 30, along the optical axis direction of the subject light flux by the objective lens system 21 as shown in FIG. It is moved in the direction D as shown. As described above, the same parallax correction effect can be obtained even when the first prism 22 is operated along the optical axis of the light beam reflected and deflected by the first reflection surface 22a. .

Therefore, the image in the field mask 23 moves from the position E shown in FIG. 10 to the position F, and the same object arrangement as the screen actually shot is seen as a finder image, and parallax is corrected. . When the object distance changes from a long distance to a short distance and the first prism 22 is moved, the optical path length from the objective lens system 21 of the finder to the field mask 23 changes in a direction in which it is extended. However, in practice, for a subject at a short distance, FIG.
As shown in FIG. 1, the image position is shifted by Δ in a direction away from the objective lens system 21, that is, in a direction approaching the eyepiece lens system 25. For this reason, as described above, the shift in the direction in which the optical path length is extended beyond infinity becomes a shift in the direction of maintaining the finder diopter, and a secondary effect of maintaining the diopter can be obtained.

As described above, the parallax generated based on the subject distance or the subject distance and the zoom focal length can be appropriately corrected in accordance with the magnitude. Also, a first prism 22 as a first reflecting means
Since the second prism 24 and the second prism 24 have the same shape, they can be used as common components, and the number of components can be reduced. Further, since the movement of the first prism 22 accompanying the parallax correction acts in the diopter correction direction, it is possible to correct the finder diopter shift simultaneously with the parallax correction. Instead of moving the first prism 22 to correct the parallax, the second prism 24 or the field mask 23 may be moved.
Two or more of the field mask 23 and the second prism 24 may be combined and moved.

[0060]

As described above, according to the first aspect of the present invention, an objective lens having a positive refractive power is sequentially provided from the object side.
A field mask arranged near the focal plane of the objective lens,
And an eyepiece for observing an object image formed on the focal plane of the objective lens, and two reflecting surfaces in an optical path between the objective lens and the focal plane of the objective lens. A first reflecting means having an optical path between the focal plane of the objective lens and the eyepiece.
By disposing a second reflecting means having two reflecting surfaces and moving at least one of the first reflecting means, the field mask and the second reflecting means,
Since parallax can be corrected appropriately, parallax can be corrected properly with a correction amount corresponding to the size of parallax with a simple configuration with a small number of parts, and it can respond to changes in focal length. The obtained real image type finder can be provided.

According to the real image type finder of the present invention, the entrance surface of the first reflection surface of the first reflection unit and the exit surface of the second reflection surface of the first reflection unit are: The incident surface of the first reflecting surface of the second reflecting unit and the emitting surface of the second reflecting surface of the second reflecting unit are located on the same plane, and are located on the same plane, and The respective planes of the first and second reflecting means are parallel to each other, and the first and second reflecting means are arranged so that the second reflecting means is shifted (rotated) with respect to the first reflecting means. Can have a common configuration, and the parallax correction amount can be appropriately adjusted with a small number of components.

According to a third embodiment of the present invention, the driving means controls the first reflecting means by the first reflecting surface of the first reflecting means in accordance with the subject distance information. Since the first reflecting means is driven in accordance with the subject distance by including the means for moving in the optical axis direction after the deflection, the parallax is appropriately corrected in accordance with the subject distance. It becomes possible.

According to the real image type finder of the present invention, the driving means switches the first reflecting means in accordance with the subject distance information and the focal length information to the first reflecting means of the first reflecting means. The first reflecting means is driven in accordance with the object distance and the focal length by including a means for moving in the optical axis direction after being deflected by the reflecting surface of the object. Correction can be made appropriately according to the distance and the focal length.

According to the real image type finder of the present invention, the entrance surface of the first reflection surface of the first reflection unit and the exit surface of the second reflection surface of the first reflection unit are: The incidence surface of the first reflection surface of the second reflection means and the emission surface of the second reflection surface of the second reflection means are orthogonal to each other, and the emission surfaces of the first reflection means are orthogonal to each other. The entrance surface of the first reflection surface and the exit surface of the second reflection surface of the second reflection unit are parallel to each other, and the exit surface of the second reflection surface of the first reflection unit and the exit surface of the second reflection unit. The first reflecting surface of the second reflecting means is parallel to the incident surface of the first reflecting surface.
And the second reflecting means can have a common configuration,
The parallax correction amount and the finder diopter can be appropriately adjusted with a small number of parts.

According to the real image type finder of the present invention, the driving means switches the first reflecting means according to the subject distance information on the first reflecting surface of the first reflecting means. Since the first reflecting means is driven in accordance with the subject distance by including the means for moving in the direction of the incident optical axis, the parallax is appropriately corrected according to the subject distance, and the finder diopter is increased. It becomes possible to correct.

According to the real image type finder of the present invention, the driving means switches the first reflecting means in accordance with the subject distance information and the focal length information to the first reflecting means of the first reflecting means. Since the first reflecting means is driven in accordance with the subject distance and the focal length by including the means for moving the reflecting surface in the direction of the incident optical axis, the parallax is adjusted to the subject distance and the focal length. Accordingly, it is possible to appropriately correct the finder diopter and to correct the finder diopter.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a configuration of a main part of a camera to which a real image type finder according to a first embodiment of the present invention is applied.

FIG. 2 is a perspective view schematically showing a configuration of a finder optical system in the camera of FIG.

FIG. 3 is a front view schematically showing an arrangement configuration of each optical system in the camera of FIG.

FIG. 4 is a schematic view of a finder image for explaining the operation of the camera shown in FIG. 1;

FIG. 5 is a partial schematic diagram for explaining the operation of the camera in FIG. 1;

FIG. 6 is a block diagram schematically showing a configuration of a main part of a camera to which a real image type finder according to a second embodiment of the present invention is applied.

FIG. 7 is a perspective view schematically showing a configuration of a finder optical system in the camera of FIG.

8 is a front view schematically showing an arrangement configuration of each optical system in the camera of FIG.

FIG. 9 is a schematic view of a finder image for explaining the operation of the camera of FIG. 6;

FIG. 10 is a partial schematic diagram for explaining the operation of the camera in FIG. 6;

11 is a diagram schematically showing an image position on an optical path for explaining the operation of the camera in FIG. 6;

[Explanation of symbols]

 1, 21 Objective lens system 1A, 21A Objective first group lens 1B, 21B Objective second group lens 2, 22 First prism 2a, 22a, 4a, 24a First reflecting surface 2b, 22b, 4b, 24b Second reflecting surface 3,23 Field mask 4,24 Second prism 5,25 Eyepiece lens system 6,26 Actuating member 6a, 26a Rack 7,27 Motor 7a, 27a Pinion 8,28 Photographic lens system 9,29 Subject distance detection device 10, 30 Zoom focal length detection device 11, 31 Prism drive device

Claims (7)

[Claims] 1. An objective lens having a positive refractive power and disposed on the object side, a field mask disposed near a focal plane of the objective lens, and formed on the focal plane of the objective lens. An eyepiece for observing an object image; a first reflecting means disposed in an optical path between the objective lens and the focal plane of the objective lens, the reflecting means having two reflecting surfaces; A second reflecting means disposed in an optical path between a focal plane and the eyepiece and having two reflecting surfaces; and at least one of the first reflecting means, the field mask and the second reflecting means And a driving means for moving the camera to correct parallax. 2. An entrance surface of a first reflection surface of the first reflection unit and an exit surface of a second reflection surface of the first reflection unit are located on the same plane, and the second reflection unit is provided. The entrance surface of the first reflection surface and the exit surface of the second reflection surface of the second reflection means are located on the same plane, and the planes of the first and second reflection means are mutually separated. 2. The real image type finder according to claim 1, wherein the finder is arranged in parallel and shifted by 90 [deg.] From each other. 3. The driving means according to the object distance information,
3. The real image type finder according to claim 2, further comprising: means for moving the first reflecting means in the optical axis direction after being deflected by the first reflecting surface of the first reflecting means. 4. The driving means moves the first reflecting means in the direction of the optical axis after being deflected by the first reflecting surface of the first reflecting means according to the subject distance information and the focal distance information. 3. The real image type finder according to claim 2, further comprising a moving unit. 5. An entrance surface of a first reflection surface of the first reflection unit and an exit surface of a second reflection surface of the first reflection unit are orthogonal to each other, and the first reflection surface of the second reflection unit. And the exit surface of the second reflection surface of the second reflection means,
The incident surface of the first reflecting surface of the first reflecting device and the exit surface of the second reflecting surface of the second reflecting device are perpendicular to each other, and the first reflecting device is parallel to each other. The real image type finder according to claim 1, wherein the exit surface of the second reflection surface and the entrance surface of the first reflection surface of the second reflection means are parallel to each other. 6. The driving means according to subject distance information,
6. The real image type finder according to claim 5, further comprising means for moving the first reflecting means in a direction of an incident optical axis of a first reflecting surface of the first reflecting means. 7. The driving means includes means for moving the first reflecting means in the direction of the incident optical axis of the first reflecting surface of the first reflecting means according to the subject distance information and the focal length information. 6. The real image type finder according to claim 5, wherein: