JPH0722662Y2 - Viewfinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a structure of an eyepiece part of a viewfinder using a relay optical system as an eyepiece optical system.

[Conventional technology]

Conventionally, the device of the eyepiece of the viewfinder has a structure as shown in FIG. In FIG. 3, the rearmost lens 3 is through a lens barrel 3 ', and the eyepiece eyepiece 2 is a cylindrical member 1
The eyepiece 16 is fixed to the body through the. The observer pressed his face against the member 2 and observed the finder while maintaining the positional relationship between the eyes and the eye points of the optical system.

Further, when a rubber eyecup like the member 2'is used, in the case of the naked eye, the rubber eyecup is attached, and when eyeglasses are used, the rubber eyecup is folded back for 2 "and the finder is observed.

Although 35mm single-lens reflex cameras have been used for a long time, small format films have been put into practical use due to recent improvements in photosensitive materials, while solid-state imaging devices have begun to be used instead of films with the progress of integrated circuit technology.

For manufacturing reasons, the image pickup surface of a solid-state image pickup device is smaller than 35 mm film, and is generally the same as that of a small format film.

Various restrictions arise when manufacturing a single-lens reflex camera using these. One of them is the viewfinder magnification.

With the current 35mm SLR type, the viewfinder magnification is about 0.8x, which is well established as a value that does not cause visual discomfort. For 35 mm film, the screen size is 36 x 24
mm is 8.8 x 6 for small format 2/3 inch image sensor.
6 mm. If a viewfinder using a conventional penta-type optical system is applied here, it will be a very small viewfinder image of about 0.4 times, and it will be difficult to visually use it as if you are looking inside a cave. is there.

With a conventional viewfinder using a pentaprism, it is difficult to keep the camera body at the same size in order to increase the magnification. Considering the operability and maneuverability of the camera device, if it is smaller than the present, it will not be noticed, and if it becomes larger, the original maneuverability will be impaired.

Therefore, there is a method of using a relay optical system instead of the conventional penta prism.

[Problems to be solved by the device]

When a relay optical system is used, the magnification is good, but the pupil power is small because the lens power of the relay lens is large. For this reason, there is a drawback in that the finder image cannot be seen even if the eye is slightly displaced from the position of the regular eye point.

That is, there is a problem in that a viewfinder using a relay optical system has an extremely narrow eye point allowable width.

If the position of the optical system and the eyepiece eyepiece is fixed, and the distance from the eyepiece eyepiece to the eye point determined by the optical system is fixed to a constant value, the observer can see the eye in line with the eye point. Observe the best image without vignetting.

However, it is impossible to match the eyepoint with the eye depending on the distance between the eyepiece eye contact and the eye, and the distance between the eyeglass and the eye depending on whether eyeglasses are used due to the difference in the individual facial shape of the observer. There is a problem that there are cases.

Here, in order to increase the allowable width of the eye point in the relay optical system, it is conceivable to increase the lens effective diameter in order to avoid a feeling of strangeness in the visual sense. In order to achieve compactness, a lens with a small focal length F can be used by using a small screen size, but if the lens aperture of the finder is increased, the compactness is contradictory, and it becomes more difficult to correct aberrations. There is a point.

For example, in order to correct aberrations practically and prevent enlargement,
The pupil diameter can only be about 4 mm.

On the other hand, the rubber eyecup has a structure that can be folded back when a predetermined force is applied. Therefore, it is possible to position the eye substantially at the eye point depending on whether or not the naked eye and glasses are used.

However, when used with the naked eye, the rubber eyecup has elasticity and is folded back carelessly, so that the position of the eye easily shifts from the eyepoint. Therefore, in a viewfinder using a relay optical system having a narrow eye point allowable width, a good viewfinder image cannot be observed, and further, the viewfinder image cannot be seen.

The present invention has been made in view of such a conventional problem, and when a relay optical system is used, it is possible to obtain a good finder image by placing the eye at a predetermined eye point while achieving compactness. The purpose is to provide a viewfinder that can be used.

[Means for Solving the Problems]

The first invention of the present application is a viewfinder equipped with an eyepiece optical system for guiding the finder image to the eyepiece portion in order to obtain a good finder image by positioning the eye at a predetermined eyepoint while achieving compactness. It is characterized in that it is provided with a movable mechanism capable of contacting a part of a person's face to move the eyepiece frame of the eyepiece portion in the optical axis direction of the optical system.

The second invention of the present application is provided with a fixing mechanism for fixing the eyepiece frame according to the first invention of the present invention within a movable range in order to provide a good finder image each time the eye is placed at a predetermined eye point and is used. The eyepiece frame has a structure that can be fixed at a plurality of or arbitrary positions.

Further, in order to prevent the fixed position from moving easily in the optical axis direction, the fixing support force works even when the fixing operation is insufficient or canceled.

Further, in order to prevent the fixed position from changing during the fixing operation, at the fixed position, the fixing device or its operating portion is rotated around the optical axis, or an operating force is applied in a direction perpendicular to the optical axis. The structure is fixed by.

The third invention of the present application prevents the lock or clamp in the fixed position from being inadvertently released, and even when the eyepiece is inadvertently released, the eye contact does not move in the optical axis direction. In order to provide a good viewfinder image irrespective of the angle when the eyepiece frame is used, the eyepiece frame according to the second invention of the present application is provided with a rotating mechanism capable of rotating around the optical axis at a fixed position. I am trying.

[Action]

In the first invention of the present application, the structure in which the eyepiece frame can be moved in the optical axis direction of the eyepiece optical system allows the distance from the eyepiece to the eye depending on the individual facial shape of the observer, and whether or not eyeglasses are used. The distance between the eyeglasses and the eye can be corrected according to the individual difference of each user.

For this reason, by setting the eyepiece position arbitrarily and setting the optimal distance from the eyepiece to the eye point of the optical system according to individual differences and usage conditions of each user, the eye is positioned at the predetermined eye point. As a result, a good viewfinder image can be provided in the viewfinder even when a relay optical system is used as the eyepiece optical system.

Furthermore, even when a relay optical system is used as the eyepiece optical system, the viewfinder is designed so that it is possible to use a lens having a large lens power and a small aperture, regardless of the position of the eye point and the size of the pupil diameter, thus achieving compactness. It became easier.

In the second eye device of the present invention, the eyepiece frame according to the first eye device of the present invention has a structure capable of being fixed at a plurality of or arbitrary positions within a movable range, so that the eye is fixed at a predetermined eye point during use. It is possible to prevent misalignment and provide a good finder image each time it is used.

Here, when the fixed position is set to an arbitrary place, it is possible to perform fine adjustment in accordance with individual users and correction of a proper eye-catching position corresponding to different users. Further, when the fixed position is set in stages, it is easy to correct the position of the eye contact, and in particular, it is easy to correct the distance between the eyeglasses and the eye depending on whether or not the eyeglasses are used.

In addition, even if the fixing operation is inadequate or released, the structure that exerts the fixing support force prevents the fixed position from moving inadvertently in the optical axis direction, and prevents the finder from moving due to misalignment of the eyepiece during use. Vignetting of the image is prevented.

Further, in the fixed position, the fixing device or its operating portion is fixed by rotating the optical device around the optical axis or by applying an operating force in a direction perpendicular to the optical axis. In this case, the fixed position is prevented from fluctuating, and it is easy to fix the target at the proper position.

According to the third invention of the present application, the eyepiece frame of the eyepiece part according to the second invention of the present application is structured to be rotatable around the optical axis at the fixed position, so that the lock or clamp at the fixed position is inadvertently released. In addition, even if it is inadvertently released, the eyepiece can be prevented from moving in the optical axis direction, and the eye can be placed at a predetermined eye point to provide a good viewfinder image regardless of the angle at the time of use. I am training.

〔Example〕

 Embodiments will be described with reference to the drawings.

In FIGS. 1A and 2A, the rearmost lens 3 of the eyepiece is fixed to a body frame (not shown) via a lens barrel 3 '. The eyepiece outer cylinder 1 is inscribed in a member 50 fixed to a body frame (not shown), and is fixed to the body frame so as not to move in the optical axis direction of the eyepiece optical system and its vertical direction.
The eyepiece inner cylinder 4 is inscribed in the eyepiece outer cylinder 1. The eyepiece inner cylinder 4 has an eyepiece 2 and a pin 8, and the pin 8 is guided to a groove 1a cut in the optical axis direction on the inner surface of the eyepiece outer cylinder 1 that is inscribed in the eyepiece inner cylinder 4. As a result, the inner cylinder 4 is movable in the outer cylinder 1 in the optical axis direction.

In FIG. 1B, a rotating ring 5 that rotates around the optical axis on the outer peripheral surface of the distal end portion of the outer cylinder 1 has a pin 7 and circumscribes the eyepiece outer cylinder 1. The pin 7 moves in a groove 1b that is cut in a circumferential direction around the optical axis on the outer surface of the eyepiece outer cylinder 1 depending on the rotation of the rotating ring 5. A top 6 having a taper is formed in the groove 1b.
It is interposed between the pin 7 and the eyepiece inner cylinder 4. By rotating the rotary ring 5, the pin 6 has a taper top 6 and an eyepiece inner cylinder 4
And the eyepiece inner cylinder 4 is fixed to the outer cylinder 1 at an arbitrary expansion / contraction position by a frictional force.

FIG. 2A shows another embodiment, for example, a two-stage switching type corresponding to the presence or absence of glasses. The eyepiece inner cylinder 4 has a recess
There are two 13 at different points in the optical axis direction, and pin 9 is here.
It is fixed by being fitted. In Figure 2B, pin 9 is
It is attached to a plate 15 which rotates in the optical axis direction around a pin 12 provided in a groove formed in the inner surface of the eyepiece outer cylinder 1 in a circumferential direction around the optical axis. The pin 9 is constantly pressed against the eyepiece inner cylinder 4 by the spring 10, and by pushing the operation pin 11 toward the optical axis, the pin 9 is opposed to the spring force.
Can be released from the eyepiece inner cylinder 4 and the concave portion 13 and released. It goes without saying that the number of recesses 13 can be adjusted.

[Effect of device]

As described above, according to the present invention, it is possible to match the position of the eyes of the user with the eye point regardless of the position where the eye point of the optical system is set, so that a good visual field can be obtained even if the user is different. You can

In addition, the constraint of the optical system that comes from focusing on the eye point is relaxed, and a more compact optical system can be adopted.
It is possible to downsize the entire device.

By fixing the eye contact position, it does not move easily in the optical axis direction even when it is pressed with a strong force like when using a rubber eyecup. Therefore, a good finder image can always be obtained.

Since the structure of the fixing device is as described above, it is possible to prevent the displacement of the eye contact due to the fixing operation.

Further, according to the embodiment shown in FIG. 1, the position of the eye contact can be finely adjusted, and an optimum finder image of the observer can be obtained. According to the embodiment shown in FIG. 2, there is an advantage that the user can easily adjust the eyepiece contact.

[Brief description of drawings]

1A and 2A are vertical cross-sectional views of an embodiment of a movable eyepiece. FIG. 1B FIG. 2B is a cross-sectional view of the fixing device portion in the embodiment of the movable eyepiece portion. FIG. 3 is a vertical cross-sectional view of a conventional eyepiece embodiment. [Description of symbols of main parts] 1 ... Eyepiece outer cylinder fixing part member, 1a ... Movable eyepiece movement guide groove, 1b ... Rotating ring guide groove for pressing and fixing, 2 ... Eyepiece eyepiece, 2 ′, 2 ″ …… Rubber eyecup, 3 …… Last lens of eyepiece, 3 ′ …… Lens barrel of eyepiece, 4 …… Moveable member of eyepiece inner cylinder, 5 …… Pressing Rotating ring for fixing, 6 …… Fixing piece, 7 …… Pressing fixing pin, 8 ……
Pin, 9 …… Inset fixing pin, 10 …… Inset fixing pin Presser spring, 11 …… Inset fixing operation pin, 12 …… Rotating support pin for inset fixing pin, 13 …… Indentation, 50 …… Eyepiece fixing member.

Claims (3)

[Scope of utility model registration request] 1. A viewfinder equipped with an eyepiece optical system for guiding a viewfinder image to an eyepiece section, wherein an eyepiece frame of the eyepiece section, which is capable of contacting a part of a face of an observer, is provided with light of the optical system. A viewfinder characterized by having a movable mechanism that is movable in the axial direction. 2. The viewfinder according to claim 1, further comprising a fixing mechanism for fixing the eyepiece frame within a movable range. 3. The viewfinder according to claim 2, further comprising a rotating mechanism that allows the eyepiece frame to rotate about the optical axis at a fixed position.