JPH10161230A - Flange back adjustment mechanism for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely secure the dimensional accuracy of flange back by simple adjustment work by constituting a mechanism so that the position of a pressing plate in the optical axis direction of a lens can be directly adjusted by a position adjustment mechanism for a pressing plate. SOLUTION: A pair of external rails 7 is constituted so that the side edges of a film 4 in a width direction are freely slidably guided by a pair of mutually facing side wall surfaces 7a projecting to a back surface side from a pair of side edge parts at the wall part 2a of an aperture 3 along in the traveling direction of the film. Then, groove parts 16 where the tip parts 7b of the rails 7 enter are formed at one part of the front surface 6a of the pressing plate 6 facing a pair of rails 7. That means, the side edges of the film 4 in the width direction are positioned between the mutually facing side wall surfaces 7a of the rails 7. When the prescribed gap and the parallelism of the position of a pressing plate 6 with respect to a mount surface for attaching the lens is secured, the plate 6 can be moved forward and backward with respect to the optical axis I of the lens by screwing and adjusting the screws for adjustment 13 of the position adjustment mechanism for a pressing plate 10 arranged at four places of the plate 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for adjusting the flange back of a camera for securing the size of the flange back of the camera. The present invention relates to a flange back adjustment mechanism for a camera applied to an aperture portion formed by an outer rail that is positioned and travels.

[0002]

2. Description of the Related Art In a camera, one of the conditions to be satisfied to enhance the photographing performance is to ensure the accuracy of the flange back dimension. That is, the flange back is the distance from the reference surface by the lens mounting mount on the front side of the camera body main body for mounting the interchangeable lens in the camera to the film surface which is the focal plane. It is necessary to manufacture the back with the correct dimensional accuracy as much as possible.

FIG. 3 is an enlarged view of an aperture portion 1 provided on the back side of a dark box in a conventional camera. In FIG. This is a camera body main body constituting a dark box provided so as to surround a photographic lens optical path at the center and exposing a film with photographic light. This camera body 2
A wall portion 2a having an aperture 3 which is a rectangular opening for defining a photographing screen for projecting photographing light passing through a photographing lens (not shown) onto a film surface is formed in a portion constituting the rear side of the dark box. .

In such an aperture part 1, a pressure plate 6 is disposed further behind the aperture 3 with a gap forming a film running path 5 for running the film 4 in a direction perpendicular to the plane of the drawing. ing. This pressure plate 6
Is urged by a spring (not shown) on the back of a back cover (not shown) provided on the back of the camera so as to be in close contact with the surface opposite to the emulsion surface of the film 4. It is supported so as to maintain the flatness of the film 4.

Reference numerals 7 and 7 denote a pair of outer rails projecting rearward from a wall 2a of the camera body 2 which constitutes a pair of side edges along the film running direction of the aperture 3.
These outer rails 7, 7 are configured to slidably guide the side edges in the width direction of the film 4 on the side wall surfaces facing each other. The side walls of the outer rails 7, 7 that guide the side edges of the film 4 are configured to position the film 4 in the width direction on the running path 5. The end surfaces of the outer rails 7, 7 are in contact with the surface of the pressure plate 6. The outer rails 7 form a film traveling path 5 by the wall 2 a having the aperture 3 and the pressure plate 6.

Reference numerals 8, 8 denote inner rails protruding rearward from near the side edges of the aperture 3 in the wall portion 2a. These inner rails 8, 8 are exposed to the film 4 traveling on the film traveling path 5. The emulsion surface is slidably in contact with a side edge portion in the width direction of the emulsion surface. These inner rails 8,
The reference numeral 8 is provided closer to the side edge of the aperture 3 than the outer rails 7 and 7, and the protrusion amount is small. Note that I in the figure is a lens optical axis of a photographing lens not shown.

In the aperture section 1 having such a configuration, in order to secure the dimensional accuracy of the flange back described above, the pressure plate 6 for defining the position of the film 4 from the lens mounting mount (not shown) of the camera body 2 is required. It is necessary to arrange the surface at a predetermined position on the optical axis I of the lens. Conventionally, in order to secure such a flange back dimension, the outer rail machining method is realized by cutting the end surfaces of the distal end portions of the outer rails 7, 7 in contact with the surface of the pressure plate 6 to a predetermined amount by machining. ing.

As a method for inserting the washer, when the lens mount is attached to the camera body 2, a predetermined amount of washer having various thicknesses is provided between the mount and the camera body 2. There is also known one in which a thicker one is inserted and interposed to secure a predetermined value of the flange back dimension between the mount and the film surface, that is, the surface of the pressure plate 6.

[0009]

However, in the above-described conventional method of adjusting the flange back, any of the above-described methods causes the following problems. That is, in the former outer rail machining method, since the cutting process must be performed on the end surfaces of the distal ends of the outer rails 7 and 7 while confirming the dimensional accuracy, the machining becomes complicated and causes an increase in cost. Further, in order to prevent chips generated at the time of processing from entering the camera body 2, especially the dark box, it is necessary to perform masking to cover the aperture 3 and other openings and holes formed at appropriate positions. Therefore, work efficiency is poor.

Further, in order to allow the film 4 to pass through the film running path 5 in the above-described aperture section 1,
Since the outer rails 8 and 7 need to have a step,
It is necessary to cut the inner rails 8, 8 by an amount corresponding to the cutting allowance of the outer rails 7, 7. In addition, the processed surfaces of the inner rails 8, 8 always slide while the film 4 is running, so that the surface of the film 4 may be damaged. Therefore, it is necessary to make the surface roughness of the processing surface, which is the end face of the tip of the inner rails 8, 8, as small as possible.
There is also a problem that workability is poor.

On the other hand, according to the latter washer insertion method,
When mounting a mount for mounting a lens on the camera body 2, it is necessary to perform work of measuring a plurality of types of thicknesses of washers, sequentially inserting the mounts, and obtaining the dimensional accuracy of a predetermined flange back with respect to the pressure plate. ,
Preparing various types of washers increases the number of man-hours and increases the cost. Moreover, such washers have a finite thickness, and even if they are combined, the thickness obtained is limited in terms of accuracy, and it is difficult to secure an appropriate value for the flange back dimension.

Further, the above-mentioned mount and outer rails 7, 7
If the parallelism with is not ensured, select washers with different thickness in the circumferential direction among multiple washers,
It is necessary to insert this as appropriate and incorporate it, and there is a problem that the work is complicated, and taking such a point into consideration, it is necessary to take measures to easily secure the dimensional accuracy of the flange back. Is desired.

The present invention has been made in view of such circumstances, and in order to manufacture a flange back with a correct dimension and to secure the flange back, adjustment of the flange back dimension is performed by a simple operation and stable. The dimensional accuracy can be ensured, and the parallelism between the lens mounting mount for mounting the lens on the front side of the camera body and the pressure plate that supports the film so that it can run freely can be secured stably. An object of the present invention is to obtain a flange back adjustment mechanism for a camera.

[0014]

In order to meet such a demand, a flange back adjusting mechanism for a camera according to the present invention comprises an aperture provided in a camera body main body constituting a dark box, and an aperture extending along a film running direction of the aperture. A pair of outer rails projecting rearward from the pair of side edges and slidably guiding the side edges in the width direction of the film on the side walls facing each other, and an aperture on the rear side of the dark box through the film running path. A pressure plate which is disposed so as to face the emulsion surface of the film and is in close contact with the surface opposite to the emulsion surface of the film; and a pressure plate position adjusting mechanism which can adjust the position of the pressure plate in the optical axis direction of the lens. A groove is provided at a position opposed to the groove, into which the tip of the outer rail enters.

Here, the flange back adjustment mechanism of the camera according to the present invention supports a pressure plate position adjusting mechanism that enables the position of the pressure plate in the optical axis direction of the lens to be adjusted by the pressure plate with respect to the camera body via an elastic member. Provided to be
Further, a pressure plate position adjusting mechanism for supporting the pressure plate with respect to the camera body main body is constituted by at least three mounting portions.

According to the present invention, in order to secure the dimensional accuracy of the flange back, the position of the pressure plate in the lens optical axis direction can be directly adjusted by the pressure plate position adjusting mechanism. The dimensional accuracy can be reliably ensured by a simple adjustment operation. According to the present invention, even when the position adjustment operation of the pressure plate is performed, the film is positioned in the width direction of the film by the opposing side wall surfaces of the pair of outer rails configured to be able to advance and retreat relative to the pressure plate. And a highly reliable camera can be obtained.

The flange back is a distance from a mounting flange surface of a lens mounting mount for mounting an interchangeable lens to a film surface which is a focal plane, and the film surface corresponds to a surface of a pressure plate supporting the film from the back side. . The pressure plate position adjusting mechanism includes a screw, which is a fastening component for connecting the camera body main body and the pressure plate so as to be relatively movable, and a spring, which is an elastic member.

[0018]

1 and 2 show one embodiment of a flange back adjusting mechanism for a camera according to the present invention. In these figures, the same or corresponding parts as those in FIG. Numbers are assigned and explanations are omitted. FIG. 1 also shows only the aperture portion of the camera main body and the pressure plate attached to the camera back cover, which constitute the film traveling path, as in FIG. 3, but the other configurations are conventionally widely known. As such, a specific description and illustration are omitted.

According to the present invention, in the aperture portion 1 of the camera body 2 constituting the dark box, the aperture 3 is provided as a mechanism for performing the flange back adjustment by adjusting the position of the pressure plate 6 in the direction of the lens optical axis I. A pressure plate position adjusting mechanism 10 which is arranged so as to face the film running path 5 and is in close contact with the emulsion surface 4a and the opposite surface 4b of the film 4 so as to adjust the position in the lens optical axis direction (I) of the pressure plate 6. Is provided.

The pressure plate position adjusting mechanism 10 as shown in FIG.
As shown in FIG. 2, an adjusting screw mounting portion 11 protruding toward the outer end on the back side of the wall portion 2 a of the camera body 2, and near the outer edge of the pressure plate 6 opposed to the mounting portion 11. Cup-shaped mounting portions 12 provided on the
1 and 12 are constituted by an adjusting screw 13 for fastening the two members in an adjustable state, and a compression coil spring 14 interposed between the two members at the mounting portions 11 and 12.

That is, the pressure plate 6 is attached to the mounting portions 11, 1
2 and a compression coil spring 14 interposed therebetween, a predetermined gap is disposed on the back side of the aperture section 1 of the camera body 2 and is fixed by screws 13 for adjustment. And this adjusting screw 1
By adjusting the amount of screwing, the surface 6 of the pressure plate 6 can be adjusted.
a is substantially in close contact with the emulsion surface 4b of the film 4 running at a position corresponding to the aperture 3.

In this embodiment, such a pressure plate position adjusting mechanism 10 is provided at four locations on the upper surface and lower edge of the surface 6a of the pressure plate 6, as shown in FIG. And
At these four locations, a compression coil spring 14 is disposed between the back side of the aperture 1 of the camera body 2 and the pressure plate 6. Here, the urging force of these compression coil springs 14 acts in a direction to move the pressure plate 6 away from the camera body 2 to the rear side, but this urging force is received by the screwing position of the adjusting screw 13. I have.

If the adjusting screws 13 are screwed and adjusted, the compression coil spring 14 is extended and retracted to move the pressure plate 6 forward and backward in the direction of the lens optical axis I, and the position of the pressure plate 6 can be adjusted. In addition, if the adjustment amount of the pressure plate position adjusting mechanism 10 provided at the four positions as described above is appropriately adjusted, the inclination of the pressure plate 6 in addition to the position in the optical axis direction of the lens can be freely adjusted.

Further, according to the present invention, the side wall surfaces 7a, 7a, which project rearward from a pair of side edges of the wall 2a of the aperture 3 along the film running direction and face each other.
As shown in FIGS. 1 and 2, a part of the surface 6 a of the pressure plate 6 facing the pair of outer rails 7, which guide the side edges in the width direction of the film 4 in a slidable manner, as shown in FIGS. Rail 7,
Grooves 16, 16 into which the front end portions 7b, 7b of 7 are inserted are provided. That is, the above-mentioned outer rails 7, 7 are necessary to obtain a mechanism for positioning the side edge in the width direction of the film 4 between the side wall surfaces 7a, 7a facing each other, while the pressure plate 6 is moved in the lens optical axis direction. In order to move forward and backward, the groove 1 into which such outer rails 7, 7 can enter is provided.
6 and 16 need to be provided.

In the above configuration, in order to secure the flange back in the camera, that is, the position of the lens mounting mount and the film surface (emulsion surface), the surface 6a of the pressure plate 6 is positioned and adjusted in the lens optical axis direction. Is required. And if it does in this way, the surface 6a of the pressure plate 6
Is determined in the optical axis direction of the lens. According to the embodiment of the present invention, the press plate position adjusting mechanism provided at four positions of the press plate 6 for securing the position of the press plate at a predetermined interval and parallelism with respect to a mount surface for mounting a lens (not shown). This can be achieved by adjusting the screw 13 for adjustment in 10 and screwing the pressure plate 6 forward and backward with respect to the optical axis I of the lens.

Here, at the adjustment position of the pressure plate 6 thus determined, the distance between the pressure plate surface 6a and the sliding surface of the inner rails 8, 8 is sufficient for the film 4 to be fed in the feed direction. In addition, the dimensions of the sliding surfaces at the tips of the inner rails 8 are determined so as to set a gap effective for securing the flatness of the film 4 in which the curling phenomenon easily occurs.

Furthermore, since the outer rails 7, 7 are arranged such that their tips 7b, 7b can enter the grooves 16, 16 provided in the pressure plate 6, they are arranged along the surface 6a of the pressure plate 6. With the film 4 disposed, both edges of the film 4 are guided by the side walls 7a, 7a of both the outer rails 7, 7, and the film 4 is positioned in the width direction. When the pressure plate 6 is adjusted forward and backward in the optical axis direction of the lens, the distal ends of these outer rails 7, 7 are sufficiently engaged so as to maintain a state of entering the grooves 16, 16 on the pressure plate 6 side. It is set to have a relationship.

That is, according to the present invention, the functions of positioning and guiding the film 4 in the width direction are performed by the outer rails 7,
The position of the pressure plate 6 in the direction of the lens optical axis for ensuring the dimensional accuracy of the flange back is ensured while the groove 7 and the grooves 16 of the pressure plate 6 into which the tip portions 7a are inserted are adjusted. The structure which can be performed by adjusting the screwing of the adjusting screw 13 in the mechanism 10 is adopted.
According to this configuration, not only can the dimensional accuracy of the flange back be adjusted by a simple adjustment operation, but also the parallelism of the pressure plate 6 with the lens mounting mount can be easily obtained. Adjustment accuracy can be reliably obtained.

It should be noted that the present invention is not limited to the structure described in the above-described embodiment, and it is needless to say that the shape and structure of each part including the structure of the entire camera may be appropriately modified or changed. is there. The above-described embodiment has been described on the assumption that the position of the pressure plate 6 can be adjusted in order to determine the position of the flange back dimension when a single-lens reflex camera with interchangeable lenses is used as the camera. However, the present invention is not limited to this. For example, the present invention can be used as a position adjusting means for a pressure plate in a compact camera which is not of an interchangeable lens type, for example, other than a single lens reflex camera.

In the above-described embodiment, the pressure plate position adjusting mechanism 10 is provided with the mounting portions 12 provided at four positions on the pressure plate 6.
And an adjusting screw mounting portion 11 which is assembled to be able to move forward and backward, and a compression coil spring 14 and an adjusting screw 13 interposed therebetween. With this configuration, since the pressure plate 6 is assembled at four locations, the pressure plate 6
The positioning stability of the film 4 can be increased and the film 4 can be stably held against the curling action force of the film 4, but the present invention is not limited to such a configuration. For example, the original function of positioning can be achieved only by providing three positions.

Furthermore, in the above-described embodiment, the pressure plate position adjusting mechanism 10 is configured to elastically support the pressure plate 6 with respect to the camera body main body 2 by the compression coil spring 14. It is needless to say that any member having elasticity such as a leaf spring widely known as an urging means may be adopted.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a pressure plate position adjusting mechanism 10 for attaching a pressure plate 6 to a rear side wall portion 2a of a camera body 2 having an aperture 3 so as to be able to advance and retreat in the optical axis direction of a lens, a compression coil spring 14 interposed between both members is provided. It comprises an adjusting screw 13 for fixing both members.

[0033]

As described above, according to the flange back adjusting mechanism for a camera according to the present invention, the rear side of the aperture provided in the camera body main body constituting the dark box extends from the pair of side edges along the film running direction. A pair of outer rails that protrude into the film and slidably guide the side edges in the width direction of the film on the side walls facing each other, and the film is disposed on the rear side of the dark box so as to face the aperture via the film running path. And a pressure plate position adjusting mechanism that can adjust the position of the pressure plate in the optical axis direction of the lens, and the outer rail is located at a position facing the outer rail of the pressure plate. Since the groove portion into which the front end portion enters is provided, the following effects can be obtained despite the simple configuration.

That is, according to the present invention, in order to secure the dimensional accuracy of the flange back, the position of the pressure plate in the direction of the optical axis of the lens can be directly adjusted by the pressure plate position adjusting mechanism. Thus, highly accurate position adjustment is possible, and the dimensional accuracy of the flange back can be reliably ensured. Therefore, according to such a pressure plate, since the film can be reliably positioned in the direction of the optical axis of the lens, a good photographed image can be obtained, and this can be achieved with a simple mechanism, and the cost is low. is there.

Further, according to the present invention, since the structure is adopted in which the front end of the outer rail is inserted into the groove provided in the pressure plate, the position of the pressure plate itself moves forward and backward with respect to the front end surface of the outer rail. In addition, positioning and guiding in the width direction of the film can be reliably performed, and the film can be appropriately run.

Further, according to the present invention, since the pressure plate is supported by the camera body via the elastic member, the rigidity of the camera body can be maintained even when an external load such as an impact from the outside of the camera is received. As a result, the pressure plate can be stably held, so that a stable photographed image can be obtained by the film stably held by the pressure plate, and a highly reliable camera can be realized.

Further, according to the present invention, by supporting the pressure plate by the pressure plate position adjusting mechanism at at least three places, a highly accurate parallelism with the lens mounting mount can be obtained, and the pressure plate with respect to the lens optical axis. Since the error in the vertical position can be set to a minimum, it is possible to obtain a camera that is excellent in accuracy in terms of shooting performance.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a flange back adjustment mechanism for a camera according to the present invention, in which an aperture as a main part is enlarged.

FIG. 2 is a front view of the pressure plate shown in FIG.

FIG. 3 is an enlarged sectional view showing an aperture section in a conventional camera.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... aperture part, 2 ... camera body main body, 2a ... wall part, 3 ... aperture, 4 ... film, 4a ... emulsion surface, 5
... Film running path, 6 ... Pressing plate, 6a ... Pressing plate surface, 7 ... Outer rail, 7a ... Side wall surface, 7b ... Tip, 8 ... Inner rail,
10: pressure plate position adjusting mechanism, 11: screw mounting part for adjustment, 1
2 mounting part, 13 adjustment screw, 14 compression coil spring, 16 groove.

Claims (3)

[Claims] 1. An aperture provided in a camera body main body constituting a dark box, and a side wall in the width direction of the film protruding rearward from a pair of side edges along the film running direction of the aperture and facing each other. A pair of outer rails that guide the edges slidably, and a pressure plate that is disposed on the back side of the dark box so as to face the aperture via the film running path and is substantially in contact with the opposite side of the emulsion side of the film. A camera provided with a pressure plate position adjusting mechanism capable of adjusting a position of the pressure plate in the lens optical axis direction, and a groove into which a tip portion of the outer rail enters at a position facing the outer rail of the pressure plate. A flange back adjustment mechanism for a camera, which is provided. 2. A camera according to claim 1, further comprising a pressure plate position adjusting mechanism for adjusting the position of the pressure plate in the optical axis direction of the lens, wherein the pressure plate is connected to the camera body via an elastic member. A flange back adjustment mechanism for a camera, which is provided so as to be supported. 3. A flange back adjusting mechanism according to claim 2, wherein a pressure plate position adjusting mechanism for supporting the pressure plate with respect to the camera body via an elastic member is constituted by at least three mounting portions. Camera flange back adjustment mechanism.