JPH0833571B2 - camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a camera such as a bifocal camera or a collapsible camera in which a lens barrel is configured to be movable forward and backward.

[Description of the Related Art] In a so-called bifocal camera capable of telephoto shooting and standard shooting, a rear converter lens is inserted on the optical axis at the time of telephoto shooting and a lens barrel is extended to make a long focus, and a rear converter at the time of standard shooting. The lens is retracted and the lens barrel is retracted to form a short focus. Since the lens barrel is configured to move forward or backward as described above, in this type of camera, the internal volume of the camera body changes according to the movement of the lens barrel. Even in a collapsible type camera in which the lens barrel is pulled out at the time of photographing and retracted at the time of storage, the internal volume of the camera body also changes.

Therefore, in the case where the inside and outside of the camera body is blocked from entering and exiting air to make the camera waterproof as described above, the movement of the lens barrel causes the internal pressure of the camera body to be positive or negative compared to atmospheric pressure. Will be changed to. That is, when closing the back cover of the camera body with the lens barrel retracted and then pulling out the lens barrel, negative pressure is created inside the camera, and conversely, with the lens barrel pulled out, the back cover is closed and then the lens barrel is closed. When retracting, the inside of the camera becomes positive pressure. Therefore, it is difficult not only to move the lens barrel, but also to change the air pressure inside the camera, which causes the film surface to fluctuate.

[Object of the Invention] The present invention has been made based on the above-described viewpoint, and an object of the present invention is to adversely affect the movement of the lens barrel and the film surface when a camera having a lens barrel capable of moving forward and backward has an airtight structure. The object is to provide a camera that does not cause

[Means for Achieving the Object] According to the present invention, the camera body having a lens barrel that can move forward and backward has an airtight structure that is at least waterproof. And a pressure correction chamber having a communication portion that communicates with the pressure correction chamber, and the pressure correction chamber is arranged so as to block the communication portion of the pressure correction chamber, and the pressure correction is performed so as to cancel the change in the internal pressure of the camera body accompanying the forward and backward movement of the lens barrel. The above object is achieved by a camera provided with an airtight elastic member for changing the volume of the chamber.

[Embodiment of the Invention] FIGS. 1 and 2 are sectional structural views showing an embodiment of the present invention when applied to a bifocal camera. FIG. 1 is for standard photographing, and FIG. 2 is for telephoto photographing. Is shown.

In the figure, reference numeral 1 denotes a camera body, a body 2, a lens barrel 3 attached to the front surface of the body 2 so as to be able to move forward and backward, a back cover 4 attached to the back surface of the body 2 so as to be openable and closable, and an upper surface of the body 2. Finder section 5 and the body
It has a pressure correction chamber 6 formed on the lower surface of 22.

The lens barrel 3 includes a master lens 7 and a master lens 7
A shutter mechanism 8 also serving as an aperture arranged rearward of the shutter mechanism 8 and a rear converter lens 9 disposed rearward of the shutter mechanism 8 are attached. The lens barrel 3 is retracted into the body 2 as shown in FIG.
Body 2 as shown in Fig. 2 during telephoto shooting
Be extended in front of. The rear converter lens 9
As is well known, it is configured to be inserted on the optical axis at the time of telephoto shooting and to exit from the optical axis at the time of standard shooting. Around the lens barrel 3, an airtight bellows member 10 that expands and contracts according to the forward and backward movement of the lens barrel 3 is provided. One end of the bellows member 10 is airtightly joined to the body 2, and the other end is airtightly joined to the tip of the lens barrel 3. An airtight lens hood 11 is provided on the front surface of the master lens 7 of the lens barrel 3, and the lens hood 11 and the bellows member 10 can at least waterproof the lens barrel 3 and the body 2. Airtightness is maintained to some extent.

The back cover 4, finder section 5 and other parts follow the well-known waterproof structure or all-weather structure.
It has an airtight structure that is at least waterproof. For example, the back cover 4 is pressure-bonded between the projecting walls 12 formed on the back surface of the body 2 and the back surface of the finder section 5 and the airtight member 13 made of soft rubber provided in the groove of the back cover 4. , The plane of the body 2 and the viewfinder section 5
The back of the is airtight.

The pressure compensating chamber 6 is sandwiched between the communicating portion 14 and the first chamber 6a and the second chamber 6a.
It is divided into room 6b. The first chamber 6a is located directly above the second chamber 6b. The first chamber 6a communicates with the inside 1a of the camera body 1 through a through hole 16 formed in the partition wall 15 between the pressure correction chamber 6 and the inside 1a of the camera body 1. 2nd chamber 6b
Communicates with the outside through a through hole 17 formed in the bottom wall 6-1 of the pressure correction chamber 6. Communication part of pressure compensation chamber 6
An airtight elastic member 18 is provided on the first chamber 6a and the second chamber 6a.
The entry and exit of air to and from the chamber 6b is blocked. The expansion / contraction member 18 is, for example, a film made of rubber, and is connected to the pressure correction chamber 6 through an adhesive or a sandwiching means.
It is airtightly fixed around. The expansion / contraction member 18 changes the volume of the pressure correction chamber 6 so as to cancel the change in the internal pressure of the camera body 1 caused by the forward / backward movement of the lens barrel 3. That is, the elastic member
When the inside 1a of the camera body 1 becomes negative pressure, it deforms into a convex shape so as to cancel out the negative pressure, and when the inside 1a of the camera body 1 becomes positive, it deforms into a concave so as to cancel out the positive pressure. The first chamber 6a and the second chamber 6b are configured to receive the deformation of the expansion / contraction member 18 depending on the negative pressure component or the positive pressure component generated by the forward and backward movement of the lens barrel 3. In other words, the first room
6a and the second chamber 6b are selected to have a volume substantially equal to the moving volume of the lens barrel 3.

With the above configuration, if the back cover 4 is opened and then closed while the lens barrel 3 is retracted, the inside 1a of the camera body 1 becomes the same as the external pressure, so that the elastic member 18 is as shown in FIG. The most contracted state, that is, the undeformed state. In this state, when the lens barrel 3 is moved forward to enter the telephoto shooting state, the forward movement of the lens barrel 3 increases the internal volume of the camera body 1. Therefore, the air pressure in the interior 1a tends to decrease, but the elastic member 18 is deformed into a convex shape toward the inside of the first chamber 6a so as to match the internal pressure and the external pressure, as shown in FIG. As a result, the air pressure inside the interior 1a is maintained at approximately the external pressure.

When the back cover 4 is opened and then closed while the lens barrel 3 is advanced, the elastic member 18 is in a non-deformed state as in the case of FIG. In this state, when the lens barrel 3 is retracted to the standard photographing state, the backward movement of the lens barrel 3 reduces the internal volume of the camera body 1. Therefore, the air pressure of the inside 1a tends to rise, but the elastic member 18 is deformed into a concave shape toward the inside of the second chamber 6b so as to match the internal pressure and the external pressure, as shown in FIG. As a result, the air pressure inside the interior 1a is maintained at approximately the external pressure.

In the above-described embodiments, the bifocal camera has been described as an example, but the present invention can be widely applied to a retractable type camera and other cameras having a configuration in which the lens barrel can be moved forward and backward.

[Effects of the Invention] As described above, according to the present invention, when the camera body configured to be able to move forward and backward through the lens barrel has an airtight structure that is at least waterproof. Since it is configured to cancel the change in the internal pressure of the camera body due to the above, the internal pressure of the camera body can be kept almost the same as the external pressure regardless of the forward and backward movement of the lens barrel, which is harmful to the movement of the lens barrel and the film surface. It is possible to provide a camera that can prevent the occurrence of the occurrence of the problem, can smoothly operate the lens barrel when the lens barrel moves, and can improve the flatness of the film surface.

[Brief description of drawings]

FIG. 1 and FIG. 2 are sectional views showing the construction of an embodiment of the present invention, and FIG. 3 is an explanatory view showing a modification of the elastic member. 1 ... Camera body, 3 ... Lens barrel 6 ... Pressure compensation chamber, 14 ... Communication part 16,17 ... Through hole, 18 ... Expandable member

Claims (1)

[Claims] 1. A camera body having a lens barrel that can move forward and backward has an airtight structure that is at least waterproof, and a first chamber communicating with the inside of the camera body and the outside of the camera body. And a second chamber that communicates with the pressure compensation chamber having a communication portion formed between the first chamber and the second chamber, and the pressure compensation chamber is provided so as to block the communication portion. The airtight expansion and contraction of the pressure compensation chamber is changed so as to be convex toward the first chamber or the second chamber so as to cancel the change in the internal pressure of the camera body due to the forward and backward movement of the lens barrel. A member, and the camera body caused by the forward movement of the lens barrel after opening and closing the back cover of the camera body with the lens barrel retracted in the first chamber and the second chamber. Negative pressure inside and moving the lens barrel forward In a state, the camera body is configured to receive the deformation of the expansion / contraction member according to the positive pressure in the camera body caused by the retraction of the lens barrel after opening and closing the back cover of the camera body. .