JPH09197527A - Method and system for controlling waterproof and internal pressure for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a waterproof function and to efficiently maintain the internal pressure and the external pressure of a camera to be substantially identical regardless of the volume change of the lens barrel parts of respective interchangeable lenses as for a camera system constituted so that the respective interchangeable lenses are provided with a zoom function. SOLUTION: The interchangeable lens 10 whose average volume at the lens barrel part is equal to or under a prescribed value is not provided with a waterproof ventilation hole. When the lens 10 is selected, air is taken in/out with respect to the camera only through a waterproof ventilation hole 3 formed on a camera body. On the other hand, the interchangeable lens 20 whose average volume at the lens barrel part is equal to or over the prescribed value is provided with the waterproof ventilation hole 22. When the lens 20 is selected, the air is taken in/out with respect to the camera through both of the hole 3 formed on the camera body and the hole 22 formed on the lens 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof / internal pressure control method and system for keeping the internal pressure of a camera substantially the same as the external pressure while maintaining the waterproofness of the camera. Relates to a waterproof / internal pressure control method in a camera system in which the interchangeable lens group is selectively attached to one camera body.

[0002]

2. Description of the Related Art Generally, in a camera equipped with a zoom mechanism, the lens barrel portion expands and contracts to change the focal length of the lens, and the volume of the entire camera changes. When the volume of the camera changes in this way, air flows in and out of the camera through an appropriate gap in the camera. That is, when the volume of the camera increases, the outside air is taken into the camera, while when the volume of the camera decreases, the air inside the camera is discharged to the outside, so that the pressure inside the camera becomes substantially the same as the external pressure. This keeps the lens barrel smooth and expands and contracts.

On the other hand, if a waterproof treatment is applied to such a camera, the camera is sealed from the outside, so that air cannot flow in and out. Therefore, an opening is provided in a part of the camera body, and a waterproof breathable cloth or waterproof breathable paper such as GORE-TEX (registered trademark), which allows the passage of air but prohibits the passage of moisture, is attached and fixed to this opening. Is proposed.

When such a structure is adopted in a camera system in which a plurality of interchangeable lenses having a zoom function are selectively attached to one camera body and used, the following problems occur. That is, such a camera system usually covers a focal length in the range of 135 to 600 mm with a plurality of interchangeable lenses having a zoom function, but each interchangeable lens has a lens barrel portion depending on its focal length range. The amount of expansion and contraction of the camera differs, and therefore the amount of volume change of the camera varies depending on which interchangeable lens is used.

When the change in the volume of the camera is small, it is possible to secure a sufficient amount of air in and out by using a relatively small waterproof ventilation hole provided only in the camera body. However, if the volume change of the camera becomes large, the load when the air is taken in and out becomes large only with a small waterproof ventilation hole. In this case, it may be possible to increase the size of the waterproof ventilation hole, but if the size becomes too large (for example, larger than the user's fingertip), the GORE-TEX will be accidentally pressed with a finger during use, and sticking There is a risk that the waterproofness may be reduced by adversely affecting the parts. It is also possible to provide multiple waterproof vents with small size, but it is inefficient to provide multiple waterproof vents in the camera body only for some interchangeable lenses (lenses with large volume changes). Not a good idea.

Therefore, a technical problem to be solved by the present invention is to achieve a waterproof function and to achieve a waterproof function in a camera system in which a plurality of interchangeable lens groups having a zoom function are selectively attached to one camera body. It is to keep the internal pressure of the camera substantially the same as the external pressure regardless of the volume change amount of the lens barrel portion of the interchangeable lens and efficiently.

[0007]

[Means, Actions, and Effects for Solving the Problems] The present invention was devised to effectively solve the above-mentioned problems.
The camera body is equipped with a waterproof ventilation hole that allows the passage of air but prohibits the passage of moisture, and for an interchangeable lens with a large change in the volume of the lens barrel, the same waterproof ventilation hole is also used for the lens barrel of the lens. Air is taken in and out of the camera through both the waterproof vents provided on the camera body and the interchangeable lens, while for the interchangeable lens with a small volume change in the lens barrel, the lens barrel is waterproof. The air is taken in and out by using only the waterproof ventilation hole provided in the camera body without providing the ventilation hole.

In the present invention, for example, 35 mm to 600 mm
In a camera system that covers the focal length in the range of 2 with a plurality of interchangeable lens groups equipped with a zoom function, the interchangeable lens with an average volume of the lens barrel part that is less than or equal to a specified value does not have a waterproof ventilation hole A waterproof ventilation hole is provided in the interchangeable lens having a volume larger than a predetermined value. Further, although these interchangeable lenses are selectively attached to one camera body, a waterproof ventilation hole is also formed in this camera body.

The "average volume of the lens barrel" means the average value of the maximum volume and the minimum volume in the case where the lens barrel portion expands and contracts to change the volume when the zoom mechanism acts.
Therefore, an interchangeable lens having a large average volume has a large volume change when the lens barrel portion expands and contracts, and an interchangeable lens having a small average volume has a small volume change when the lens barrel portion expands and contracts.
Further, in general, an interchangeable lens having a small focal length has a small average volume, and as the focal length increases, the average volume tends to increase.

When an interchangeable lens having an average volume of the lens barrel portion equal to or less than a predetermined value is selected and used, air is taken in and out of the camera only through the waterproof ventilation hole provided in the camera body. When an interchangeable lens with an average volume of the lens barrel is equal to or greater than the specified value is selected and used, air is passed through both the waterproof ventilation hole on the camera body and the waterproof ventilation hole on the interchangeable lens. Put it in and take it out.

By adopting the structure in which the air is taken in and out of the camera by the above method, the waterproof ventilation hole provided in the camera body is the minimum required commonly for all interchangeable lenses. Can be stopped.
Even when considering the interchangeable lens side, there is no need to provide waterproof ventilation holes for those with a small average volume, and it is sufficient to provide waterproof ventilation holes only for those with a large average volume that really require waterproof ventilation holes. Target.

As described above, according to the present invention, the waterproof function is achieved and the lens barrel of the interchangeable lens is achieved regardless of the volume change amount of the interchangeable lens attached to the camera body. It is possible to efficiently achieve that the internal pressure of the camera is kept substantially the same as the external pressure even if the portion expands and contracts and the volume of the entire camera changes.

The boundary value of the average volume for determining whether or not to provide the waterproof ventilation hole is determined according to the ventilation capacity of the waterproof ventilation hole and the like. Therefore, for example, if the ventilation capacity is set so that it is not necessary to provide a waterproof ventilation hole for a standard lens of 35 to 135 mm, mass production standard lenses can be produced at low cost by omitting the waterproof ventilation hole. At the same time, by forming the waterproof ventilation hole only in the telephoto lens whose production is relatively small, it is possible to achieve cost reduction when considering the whole system including one camera body and a plurality of interchangeable lenses.

Further, in the interchangeable lens having a large change in volume, it is easier to secure a space for providing the waterproof ventilation hole by the length of the lens barrel portion, as compared with an interchangeable lens having a small change in volume. Further, since the lens barrel portion of the interchangeable lens is required to have a light-shielding property, it is the actual situation that it is desirable not to provide a hole portion as much as possible, but this requirement is met.

[0015]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a camera system having two sets of interchangeable lenses with respect to the camera body 1. This camera system covers a focal length in the range of 35 to 300 mm with two sets of interchangeable lenses 10 and 20 having a zoom function.

The interchangeable lens 10 is a standard lens having a focal length of 35 to 135 mm, and the interchangeable lens 20 is a focal length of 100 to 300 mm.
It is a telephoto lens. Each interchangeable lens is selectively attached to the camera body for use. Also,
The camera system of the present invention achieves a waterproof function regardless of which interchangeable lens is attached, and an O-ring (not shown) is provided between each interchangeable lens and the mount portion 2 on the camera body side. Are disposed, and appropriate waterproof treatment is performed.

The camera body is provided with a waterproof ventilation hole 3 for letting air in and out of the camera when the lens barrel of each interchangeable lens expands and contracts to change the volume of the entire camera. The waterproof ventilation hole 3 is configured as follows. That is, an opening is formed at a predetermined position of the camera body, and a waterproof breathable film is attached and fixed so as to cover the opening. The waterproof breathable membrane is made of a material such as GORE-TEX (registered trademark) or waterproof breathable paper that allows the passage of air but prohibits the passage of moisture. By providing such a waterproof ventilation hole, the pressure inside the camera can be kept substantially the same as the external pressure even when the volume of the camera changes, and the lens barrel portion of the interchangeable lens can be smoothly expanded and contracted.

The waterproof ventilation hole 3 has a higher ventilation capacity as it is formed larger, but on the other hand, if it is too large,
If it is larger than the user's fingertip, for example, the force of the fingertip directly acts on the waterproof ventilation hole during use, which causes problems such as durability. Therefore, the waterproof ventilation hole 3 should be limited to such a size that at least the force of the fingertip does not act directly when holding the camera body. Further, it is preferable that the waterproof ventilation hole 3 is formed at a position as far as possible from the photographing optical system in consideration of the light shielding property of the camera.

The lens barrel portions 11 and 21 of each interchangeable lens are fixed portions fixed to the mount portion 2 on the camera body side.
11a, 21a and rotating parts 11b, 2 that rotate relative to the fixed part
1b. Multiple lenses in this barrel
(Not shown) are arranged in parallel, and when the rotating part rotates relative to the fixed part, the relative distance of each lens in the lens barrel changes, resulting in a change in the focal length of the interchangeable lens as a whole. To do. When the rotating part rotates relative to the fixed part in this way, the lens barrel part expands and contracts, and the volume changes.

In general, a lens with a zoom mechanism (for example, 35 to 135 mm) that fluctuates in a range of a small focal length and a lens with a zoom mechanism (for example, 100 to 300 mm) that fluctuates in a range of a large focal length have a focal point. The average volume tends to increase as the distance increases. For example, interchangeable lens 10
The minimum volume 50 mm ³ at the time of expansion and contraction of the lens barrel portion 11, the maximum volume of 57 mm ^3, therefore, the average volume is 53.5 mm ^3. On the other hand, the interchangeable lens 20, the minimum volume of 100 mm ³ at the time of expansion and contraction of the lens barrel portion 21, the maximum volume of 170 mm ^3, therefore, the average volume is 135mm ^3. In other words, an interchangeable lens with a larger focal length than the interchangeable lens 10 with a smaller focal length
20 has a larger average volume, and therefore the change in volume of the interchangeable lens 20 during expansion and contraction of the lens barrel portion is larger than that of the interchangeable lens 10.

For the interchangeable lens 10 whose volume change is relatively small, the internal pressure of the camera can be adjusted sufficiently by simply letting air in and out of the camera only through the waterproof ventilation hole 3 formed in the camera body. Therefore, the interchangeable lens 10 is not provided with a waterproof ventilation hole. However, when the volume change becomes large, the waterproof ventilation hole 3 formed in the camera body alone exerts a large load on the waterproof ventilation hole, and particularly when the lens barrel portion is quickly expanded and contracted (when the volume change rate is large). , Smooth expansion and contraction may be hindered.
In this case, it is not advisable to additionally form the above-mentioned waterproof ventilation hole in the camera body. This is because, when an interchangeable lens with a small volume change is used, such an additionally formed waterproof ventilation hole makes no sense at all and is inefficient.

Therefore, a waterproof ventilation hole 22 is formed in the lens barrel portion 21 of the interchangeable lens 20 whose volume change is relatively large. The waterproof ventilation hole 22 is similar to that provided in the camera body, and the formation method is also the same. The light-shielding property is very important in the lens barrel portion of the interchangeable lens. Therefore, in order to reliably prevent light from entering the lens barrel, an air flow path such as a curved pipe extending inward from the surface of the exterior member of the lens barrel portion is provided, and the end of this air flow path is provided inside the exterior member. It is also conceivable to arrange a waterproof breathable membrane on the part.

As described above, in the present invention, each interchangeable lens is provided with a waterproof ventilation hole when the volume change is large, and when the volume change is small, the waterproof ventilation hole is provided. The lens is not provided with a waterproof vent, but it is necessary to set the boundary value. The boundary value varies depending on the size and the ventilation capacity of the waterproof ventilation hole formed in the camera body, and is set individually.

Although the present invention relates to a camera system in which a plurality of interchangeable lenses are selectively attached to one camera body, the principle explained above is applied to a camera in which the lens cannot be exchanged. You can also do it. That is, in a camera having a zoom function, only the camera body is used for a lens barrel portion with a small volume change, and both the camera body and the lens barrel portion are used for a lens barrel portion with a large volume change. By providing the waterproof ventilation holes similar to those described above, both waterproofing and internal pressure control can be achieved in each camera.

[Brief description of drawings]

FIG. 1 is a schematic perspective view illustrating an example of a camera system according to the present invention.

[Explanation of symbols]

 1 Camera body 2 Mount 3 Waterproof ventilation hole 10, 20 Interchangeable lens 11, 21 Lens barrel 11a, 21a Fixed part 11b, 21b Rotating part 22 Waterproof ventilation hole

Claims (2)

[Claims] 1. A plurality of interchangeable lens groups having a zoom function
One interchangeable lens in (10, 20) is one camera body
In a camera system that is selectively attached to (1), if an interchangeable lens (10) with an average volume of the lens barrel part is less than a predetermined value is selected, a waterproof ventilation hole (3) provided in the camera body
If the interchangeable lens (20) with the average volume of the lens barrel part above the specified value is selected by letting air in and out through the camera only through the camera, the waterproof ventilation hole (3) provided in the camera body
By moving air in and out of the camera through both the waterproof ventilation holes (22) provided in the interchangeable lens (20), the lens barrel part (11, 21) of each interchangeable lens expands and contracts, and the camera volume changes. A waterproof / internal pressure control method for a camera, characterized in that the internal pressure of the camera is kept substantially the same as the external pressure while maintaining the waterproof even in the case. 2. A plurality of interchangeable lens groups having a zoom function
One interchangeable lens in (10, 20) is one camera body
This is a camera system that can be selectively attached to (1). Even if the lens barrel part (11, 21) of each interchangeable lens expands and contracts and the camera volume changes, the internal pressure of the camera is maintained while maintaining waterproofness. The camera body (1) is provided with a waterproof ventilation hole (3) for keeping it substantially the same as the external pressure, and the same waterproof ventilation hole (22) is exchanged when the average volume of the lens barrel portion is a predetermined value or more. A camera system, characterized in that it is provided only for the lens (20).