JPS647367B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reflex camera, and more particularly to a reflex camera having a replaceable focus plate mounting member.

How to attach and remove the focus plate unit on single-lens reflex cameras with replaceable focus plates:
Conventionally, two methods have been put into practical use. One type is for cameras with a replaceable viewfinder pentagonal prism unit, in which the pentagonal prism unit is removed from the camera body and the reticle unit is attached or removed from the top of the camera.The other type is for cameras with a fixed viewfinder prism unit. In the
The focus plate unit is attached to and detached from the lens exchange mount hole.

As an example of the former method is shown in FIG. This is done by dropping the focus plate unit into the recess 1' for attaching the plate, and when removing the focus plate unit, either take out the focus plate unit 2 located at the back of the recess 1' with your finger, or turn the camera body upside down and remove the focus plate. A method of dropping the unit was used. According to this conventional method, it is difficult to replace and remove the reticle unit.
In addition, since you have to hold the focus plate unit in your hand when replacing it, it is easy to get fingerprints on the Fresnel surface or matte surface of the focus plate and get scratches, which often has a negative effect on the viewfinder system and photometry system. It was warm.

In the latter method of attaching and detaching only the focus plate unit from the lens mount hole, an example is shown in Figure 2. Conventionally, only the focus plate was attached and detached, and the focus plate was fixed to the camera body. A focusing plate mounting member is attached to the camera body. After rotating this member and placing the focusing plate on this member with tweezers, push up the mounting member with your fingers and fix it in place. I was getting used to it. According to this method, the focus plate is made of a plastic plate that is easily scratched, so the focus plate mounting member must be made of a material with sufficient strength to accurately fix the pentaprism in a fixed position on the lower surface of the camera body. It was extremely difficult to do so, and it was mechanically complex. Also, when rotating this mounting member with your fingers to fix it in place, do not leave fingerprints on the focusing plate or mirror.
This often causes scratches, which not only has a negative effect on the photometry system and viewfinder, but also can damage the focus plate and mounting parts due to incorrect operation when replacing the focus plate. In addition, repairing and replacing the focusing plate mounting member attached to the camera body is not only inconvenient in terms of repair costs, but also disassembling it for repair may impair accuracy. Such inconveniences were also likely to occur.

Additionally, the focus plate unit itself can be removed from the reflex camera body.
There is US Patent No. 3,174,417. However, in this method, a spring is provided on the camera body side to regulate the position of the focus plate, so when the focus plate unit is attached to the camera body, the focus plate is pressed and held against the focus plate mounting member. That will happen. Therefore, the mounting error of the focusing plate mounting member on the camera body directly becomes the mounting (position) error of the focusing plate.

The present invention has been made in order to eliminate the drawbacks of the conventional replaceable focus plate as described above, and includes a focus plate mounting member that supports the focus plate and is detachable from the camera body. A spring is provided to press and position the focus plate against the positioning member of the camera body when attached to the focus plate mounting member, and when the focus plate attachment member is removed from the camera body,
It is characterized in that the biasing force of the spring does not cause deformation or the like regardless of the focus plate.

The present invention will be explained in detail below with reference to the drawings.

FIG. 3 is a perspective view showing an embodiment of the present invention in which the pentaunit of the present invention is removed and the focusing plate is replaced. In the figure, 1 is a camera body, 2 is a focusing plate mounting member, 3 is a focusing plate group, and 4 is a replacement member coupling and holding member. As a matter of course, the replacement member coupling and holding member 4 can be made into a coupling and holding part that is integrated with the focusing plate mounting member 2 instead of being made into a separate member. The focusing plate unit is attached to and removed from a recessed portion of the camera body 1 below the pentaunit.

FIG. 4 is a side view showing a state in which a replacement member is attached to the focus plate unit shown in FIG. In some cases, it can be attached and detached. Therefore, the focus plate unit 2 is connected to the camera body 1.
Even if the camera body 1 is deep in the concave part and difficult to remove with fingers, it can be easily removed using the replacement member connected to the joint holding part without turning the camera body 1 upside down. In addition, if the replacement member is provided with a focusing plate protection stopper 5 and the upper part of the focusing plate mounting member 2 is set higher than the focusing plate group 3, the member 6 will not touch the focusing plate group 3 and will not cause scratches. . Therefore, the effect is that the camera body can be easily attached and detached without having to hold it upside down and without being held by fingers, so that it can be quickly attached and detached without leaving fingerprints or dirt on the focusing plate and without causing scratches.

FIG. 5 is a plan view and a side view showing an embodiment of the present invention in which a focusing plate unit is removable from a lens mounting hole. In the figure, 2' is a coupling and fixing part for attaching the focusing plate unit to the camera body, 3' is a focusing plate, 6' is a coupling holding part of a replacement member to the focusing plate unit, and 7 is a spring that biases the focusing plate. , 8 is a reticle unit-forming attachment member that prevents the reticle from coming off the reticle unit.

As shown in FIG. 5, the focus plate 3' is attached to the focus plate mounting member 2.
is fitted, and a spring 7 is inserted into the focus plate mounting member 2.
is attached and presses the reticle in one direction. The focus plate attaching member 8 is attached to the focus plate attachment member 2 to prevent the focus plate 2 from coming off and form a unit. A replacement member coupling and holding portion 4 is provided on the reticle mounting member 2 to maintain the connection with the replacement member, so that the reticle unit can be replaced without directly touching the reticle unit.

FIGS. 6, 7, and 8 show the present invention in which the replacement member coupling and holding part and the reinforcing part of the reticle mounting member are used together to prevent undue stress from acting on the reticle when it is not installed. FIG. 2 is an exploded perspective view, a top view, and a side view of an embodiment of a reticle unit according to the present invention, and a view showing the connection of the reticle unit and a replacement member.

When the focusing plate unit is attached to the camera body, force is applied to the coupling fixing portion 2' and the spring fixing portion, so that stress and moment are applied to the focusing plate mounting member 2. At this time, if the focusing plate mounting member 2 is weak, it will deform and the focusing accuracy will be compromised. For this reason, a shoulder portion is provided inside the focus plate mounting member, and its inner circumferential portion is connected to increase the strength, and the reinforced portion is also used as the replacement tool coupling and holding portion 4. A window is provided on the side wall of the focus plate mounting member 2 where the coupling fixing part 2' is not provided, and a window is provided to catch the focus plate pressure contact spring 7, and the spring is kept in a pretensioned state. The spring is fixed at the shoulder section on the side where the coupling fixing section 2' is not present.

The method of integrating the focusing plate mounting member 2 and the focusing plate 3' into a unit is to provide the focusing plate mounting window 2'' on one of the opposing side walls where the coupling and fixing part 2' of the focusing plate mounting member 2 is located, and to open the focusing plate mounting window 2'' on the other side. The focusing plate 3' has a structure in which a part of its wall can be plastically deformed on the inside.The focusing plate 3' has a convex part 3'' that allows it to be moved up and down within the focusing range when it is made into a unit.
and a recess 3'' are provided.The convex portion 3'' of the focusing plate 3' is inserted into the window of the focusing plate mounting member 2, and the opposite wall side is formed by bending the plastically deformable portion 2 of the focusing plate mounting member 2 inward. unit. At this time, the size of the focus plate mounting window 2'' and the dimensions of the part 2 that can be plastically deformed are determined in such a state that there is play between the pressure contact spring 7 and the focus plate.When the focus plate unit is not attached to the camera body, the focus plate may have play. If it is not in use, that is, if force is applied from the pressure spring, the plastic focusing plate will be deformed by the environment such as temperature and humidity, and the focusing accuracy will be lost when it is attached. By adding some play to the spring so that no force is applied, the focus plate will not be deformed and focus accuracy can be guaranteed.Furthermore, by creating a unit with a part that can be plastically deformed, it is possible to avoid using separate parts. ,
It is very advantageous in terms of cost.

FIG. 9 is a sectional view showing the reticle unit of the present invention shown in FIGS. 6, 7, and 8 attached to a camera. Next, FIGS. 10, 11, and 12 are diagrams showing the state in which the reticle unit of the present invention is removed using a replacement member.

As shown in FIG. 10, place the coupling and holding part 6' at the tip of the replacement member against the reinforcing part and replacement member coupling and holding part 4 of the focusing plate holding member of the focusing plate unit, and push the replacement member in the direction of the arrow. While doing so, rotate the handle part 6'' around this part in the penta direction (arrow) to bring the replacement part into contact with the bottom of the shoulder, and when you stop pushing, the spring action of the connecting and holding part 6' will cause it to focus. The replacement member coupling and holding portion 4 on the opposing side of the plate unit is coupled to the replacement member.

Next, when the replacement member is unhooked and the lever 9 is pushed, the hook of the camera body is released from the coupling and fixing part 2' of the focusing plate unit, as shown in FIG. At this time, the focusing plate unit is removed from the camera body, but remains attached to the replacement member due to the springiness of the connecting and holding portion 6' of the replacement member. Therefore, by taking out the replacement member holding the focus plate unit from the mount hole, the focus plate unit can be taken out without holding it directly without soiling or scratching it.

FIGS. 13, 14, and 15 are diagrams showing the state in which the focus plate unit is attached to the camera body. As shown in FIG. 13, insert the replacement member holding the focus plate unit into the mounting hole, and insert the coupling and fixing part 2' of the focus plate unit into the receiving plate 10 on the camera body side. At this time, if a guard is provided so that the coupling and fixing part 2' can easily enter the receiving plate 9, it can enter easily. Then, when the handle 6'' is rotated in the pentagonal direction (arrow) around the coupling and fixing part 2', the coupling and fixing part 2' on the other side of the reticle unit is hooked onto the hook on the camera body side, and the replacement member Once installed as shown in Figure 14, while pushing the handle 6'' in the direction of the arrow, move the handle in the direction opposite to the penta direction (arrow) centering on the connecting and holding part 2' of the replacement part. When you rotate it, only the replacement part will come off. At this time, the focus plate unit is attached to the camera body. Next, as shown in FIG. 15, when the replacement member is pulled out from the mount hole of the camera body, the replacement of the focusing plate unit is completed.

As described above in detail using the embodiments, by constructing a reflex camera using the interchangeable focus plate unit according to the present embodiments, many effects as described below can be obtained. In other words, there will be no fingerprints, dirt, or scratches on the reticle.

Prevents fingerprints, dirt, and scratches on the up-down mirror on the camera body side.

Since the focus plate holding member is not attached to the camera side, it is easy to achieve accuracy.

Easy to operate and can be attached and detached accurately.

Even if the focus plate holding member is damaged, there is no need to disassemble the camera body for repair, and there is no need to worry about the accuracy being compromised after disassembly.

The replacement tool joint and holding part also serves as a reinforcing part, making it less likely to break.

It is low cost because it is made into units by plastic deformation.

When not installed, the force of the pressure contact spring does not act on the focus plate, so there is no accuracy loss due to deformation of the focus plate.

As explained above, even if the focus plate is supported by the focus plate mounting member that is detachable from the camera body, when the focus plate attachment member is attached to the camera body, the position of the focus plate is on the side of the camera body. Since the reticle is pressed against the positioning member by a spring, extremely high positional accuracy of the reticle can be obtained. Furthermore, in the present invention, even when the focus plate mounting member is removed from the camera body, the biasing force of the spring is not applied to the focus plate, so it is possible to provide a reflex camera that does not suffer from loss of accuracy due to deformation of the focus plate. can.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing how a conventional focus plate unit is replaced in a camera with a removable viewfinder, Fig. 2 is a sectional view showing an example of the conventional method of replacing the focus plate from the lens exchange mount hole, and Fig. 3 4 is a perspective view showing an embodiment of an exchange focus plate unit for a camera with a removable viewfinder according to the present invention; FIG. 4 is a side view showing an embodiment of a replacement member for the exchange focus plate unit shown in FIG. 3; The figures are a plan view, a side view, and a sectional view showing an embodiment of the exchangeable focus plate of the present invention, which is exchanged from the lens exchange mount hole.
The figures are exploded and assembled perspective views showing one embodiment of the exchange reticle unit according to the present invention, FIG. 7 is a plan view and a sectional view of the exchange reticle unit shown in FIG. A plan view and a sectional view showing a state in which a replacement member is attached to the illustrated exchangeable focus plate unit, and FIG. 9 is a partial sectional view showing a state in which the exchangeable focus plate unit shown in FIGS. 6 and 7 is attached to a camera body. , Figures 10, 11 and 12 are
Fig. 7 is a sectional view showing a state in which the replacement focus plate unit shown in Fig. 7 is removed from the camera body using a replacement member, Figs.
FIG. 7 is a sectional view showing a state in which the exchangeable focus plate unit shown in FIG. 7 is attached to the camera body using a replacement member. 1...Camera body, 2...Focal plate mounting member,
2'...2 coupling fixing part, 2''...focusing plate mounting window,
2... Plastic deformable part, 3... Focus plate structure,
3'...focusing plate, 3''...focusing plate mounting protrusion, 3...
...focusing plate mounting recess, 4...replacement member coupling and holding part, 5...focusing plate protection stopper, 6...replacement member, 6'...coupling and holding part of 6, 6''...handle,
7...Spring, 8...Focus plate unitization member,
9... Hook release lever, 10... Receiving plate, 11
...Mirror, 12...Mount, 13...Front plate,
14... Pentaprism, 15... Prism holder.

Claims (1)

[Scope of Claims] 1. A reflex camera having a focusing plate mounting member that supports a focusing plate and is detachable from the camera body, the focusing plate being pressed against the focusing plate mounting member in the optical axis direction. Further, a positioning portion for the focusing plate is formed on the opposite side of the spring on the focusing plate mounting member, and the optical axis is aligned between the pressing portion by the spring and the positioning portion. The focusing plate is supported movably in the direction without resisting the spring force of the spring, and when the focusing plate mounting member is attached to the camera body, the focusing plate is supported by the positioning member of the camera body and the pressing portion by the spring. 1. A reflex camera characterized in that the abutment position of the positioning member is set so that the positioning member is held and pressed by the positioning members.