JP7570675B2 - Lens cap holder - Google Patents

Description

The present invention relates to a lens cap holder that holds a lens cap for protecting the front surface of a lens mounted in an imaging device or the like.

Conventionally, various types of lens caps have been proposed to protect the front surface of a lens mounted on an imaging device or the like. In addition, each type of lens cap employs various mechanisms for attaching it to the tip of a lens mounted on an imaging device or the like.

For example, a lens cap has been proposed that is injection molded from synthetic resin. Because synthetic resin is flexible, this type of lens cap itself has elasticity. The claws of the lens cap also have elasticity, and the lens cap can be attached to the tip of the lens barrel by hooking the elastically deformed claws onto the tip of the lens barrel.

Lens caps have also been proposed that have an additional elastic mechanism consisting of a spring or the like. This type of lens cap has a mechanism that allows the claw to slide, and the elastic mechanism applies an elastic force to the sliding of the claw, so that the biased claw hooks onto the tip of the lens barrel, allowing the lens cap to be attached to the tip of the lens barrel.

Each of these conventional lens caps had the following drawbacks:

Lens caps made from synthetic resin by injection molding have the disadvantage that they deform due to temperature and aging, and are unable to maintain their original elasticity. This weakens the way the tabs grip the tip of the lens barrel, making the lens cap more likely to fall off. Furthermore, if the lens cap falls off unexpectedly, it may be lost or the lens may be damaged.

Lens caps that add an elastic mechanism composed of springs and other components have the disadvantage that the addition of a complex elastic mechanism increases parts and assembly costs, and increases weight and size. In addition, users must operate the elastic mechanism when attaching or removing the lens cap, making the process of attaching and removing the lens cap cumbersome.

Another issue with conventional lens caps is that they must be properly stored when removed from the camera to avoid losing them.

As a result, a lens cap has been proposed that can be attached to the tip of the lens barrel using magnetic force.

Patent document 1 (Japanese Utility Model Application Publication No. 57-146128) discloses a lens cap that can be attached to the tip of a lens barrel by magnetic force. This lens cap can be attached to a metal ring at the tip of the lens barrel by magnetic force when not taking pictures, and when taking pictures, it can be attracted and held to the metal plate at the bottom of the camera body by magnetic force.

Patent Document 2 (Japanese Utility Model Application Publication No. 57-74427) similarly discloses a lens cap that can be attached to the tip of a lens barrel by magnetic force. This lens cap can be attached to the ferromagnetic material around the tip of the lens barrel by magnetic force when not taking pictures, and when taking pictures, it can be attracted and held by the magnetic material on the back cover of the camera body so that it does not interfere with camera operation. The lens cap is also connected to the camera body by a cord to prevent it from getting lost.

Japanese Utility Model Application Publication No. 57-146128 Japanese Utility Model Application Publication No. 57-74427

However, the prior art disclosed in the above patent document has the following problems:

Recent digital camera bodies are equipped with a wide variety of operating parts to realize many functions, and are equipped with a large LCD for previewing captured images, making it difficult to secure space to magnetically attach and hold the lens cap to the camera body when taking pictures.

In addition, if the lens cap is magnetically attached to the camera body when taking pictures, the operability of the camera is impaired. There is also a risk that the lens cap may fall off the camera body when the user operates the camera when taking pictures. To prevent the lens cap from being lost after falling off, the lens cap must be connected to the camera body with a cord or the like.

In order to solve the above problems, a first invention of a lens cap holder according to the present invention is a lens cap holder having a recess in the center and which magnetically attracts and holds a lens cap attached to the tip of a lens barrel, the lens cap holder having a hollow disk-shaped holder base including a hollow disk-shaped suction disk member made of a ferromagnetic material, a protrusion protruding in a direction perpendicular to the plane of the holder base is formed around the hollow portion of the holder base, the protrusion is capable of fitting into the inner diameter of the recess of the lens cap, the hollow portion is of a size that allows a finger to be inserted, and the holder base has a protrusion on part of its periphery, and when a magnetically attracted lens cap is removed, a pressing force is applied to the recess by a first finger of the user inserted from the hollow portion, and at the same time, a supporting force is applied to the protrusion by a second finger of the user .

A second aspect of the lens cap holder according to the present invention is characterized in that the pressing force and the supporting force act in opposite directions .

The lens cap holder according to the present invention has the following advantages.

When shooting, the lens cap is attached and held in a lens cap holder that is separate from the camera body, preventing the lens cap from getting lost and ensuring that the lens cap does not get in the way of camera operation when shooting.

The suction disk member and holder disk member of the lens cap holder are hollow disk shaped, so the user can remove the lens cap from the lens cap holder with a simple operation.

The inner diameter of the cap body of the lens cap fits into the outer diameter of the protruding portion of the holder disc member of the lens cap holder, and the movement of the lens cap is restricted to a direction horizontal to the plane of the suction disc member of the lens cap holder, so the magnetic force that holds the lens cap in place does not change, and the lens cap is prevented from easily falling off the lens cap holder.

A protrusion is formed on part of the periphery of the suction disk member of the lens cap holder, making it easier to remove the lens cap from the lens cap holder.

At least two sets of magnets and yokes are arranged inside the lens cap along the circumference of the cap body, and are covered with flocked paper so that they are not exposed to the outside. This allows them to be concealed and prevents them from falling off the cap body. It also improves the quality of the lens cap when attached to the tip of the lens barrel or the lens cap holder.

FIG. 2 is a perspective view showing the configuration of an interchangeable lens and a lens cap of a reference example . FIG. 13 is an exploded perspective view showing the configuration of a lens cap according to a reference example . FIG. 13 is an exploded perspective view showing a configuration of a modified example of the lens cap of the reference example . 10 is a cross-sectional view showing a state in which a lens cap is attached to the tip of the interchangeable lens. FIG. 2 is an exploded perspective view showing the configuration of the lens cap holder of the present embodiment. 13 is a perspective view showing a state in which a strap is attached to a through hole of the lens cap holder. FIG. 13A and 13B are perspective views showing modified examples of protrusions formed on a part or the entire periphery of the suction disk member. FIG. 13 is a perspective view showing a modified example of the lens cap holder of the embodiment. FIG. 11 is a perspective cross-sectional view showing a modified example of the lens cap holder of the embodiment. 4 is a cross-sectional view showing a state in which a lens cap is attracted to and held by the lens cap holder; FIG. 11 is a perspective cross-sectional view showing a state in which the lens cap is removed from the lens cap holder. FIG.

An embodiment of the lens cap holder according to the present invention will now be described.

Fig. 1 is a perspective view showing the configuration of an interchangeable lens equipped with a lens barrel and a lens cap of a reference example . The interchangeable lens shown in Fig. 1 can be attached to a digital camera (not shown). The lens cap of the reference example can be attached to the tip of the interchangeable lens by an adhesive force generated by a magnetic force. In Fig. 1, the tip of the interchangeable lens is shown partially disassembled.

In FIG. 1, 100 indicates an interchangeable lens and 200 indicates a lens cap.

As described below, multiple magnet and yoke pairs are mounted inside the lens cap 200. Also, inside the tip of the interchangeable lens 100, an attraction plate 101 that circles the tip of the interchangeable lens 100 is attached with screws. The attraction plate 101 has a hollow disk shape that shares a central axis with the outer diameter of the cylindrical interchangeable lens 100. At the tip of the interchangeable lens 100, the location where the attraction plate 101 is attached is covered by a front ring 102. The multiple magnet and yoke pairs mounted on the lens cap 200 generate magnetic forces that are attracted to the attraction plate 101 of the interchangeable lens 100. The lens cap 200 is attached to the tip of the interchangeable lens 100 by this attraction force.

The suction plate 101 at the tip of the interchangeable lens 100 is covered by the front ring 102, so the user cannot see this from the outside. On the other hand, the front ring 102 is attached so as to go around the tip of the interchangeable lens 100, so the suction force can be ensured regardless of the rotational orientation of the lens cap 200 around the central axis. This ensures that the user will not fail to attach the lens cap 200.

FIG. 2 is an exploded perspective view showing the configuration of a lens cap 200 according to a reference example .

In FIG. 2, 201 indicates the cap body, 202 indicates the magnet, 203 indicates the yoke, and 204 indicates the flocked paper.

The cap body 201 is formed by cutting metal or injection molding of synthetic resin. Two sets of magnets 202 and a yoke 203 are mounted inside the cap body 201. These are attached to the cap body 201 by ultraviolet curing resin or the like. The yoke 203 has the effect of improving the stability of the magnetic force of the magnets 202 and preventing magnetic flux leakage. In order to improve the prevention of magnetic flux leakage of the magnetic force generated by the two sets of magnets 202 and the yoke 203, it is preferable to design the difference between the outer diameter and the inner diameter of the attraction plate 101 of the interchangeable lens 100 to be larger than the size of the magnets 202.

If there is only one set of magnet 202 and yoke 203 mounted inside cap body 201, lens cap 200 cannot be stably attached to the tip of interchangeable lens 100 or lens cap holder against external force. In contrast, as shown in FIG. 3, even if there is only one set of magnet and yoke, by configuring them to all have a hollow disk shape with a common central axis, lens cap 200 can be stably attached to the tip of interchangeable lens 100 or lens cap holder. In FIG. 3, 202x indicates a hollow disk-shaped magnet, and 203x indicates a hollow disk-shaped yoke.

The number of pairs of magnets 202 and yokes 203 mounted inside the cap body 201 may be more than two, but if there are too many, there will not be enough space inside the cap body 201 to mount them. In addition, the total weight of the lens cap 200 may become too large, or the adhesive force of the lens cap 200 may become too strong, which may impair the operability of attaching and removing the lens cap 200.

The flocked paper 204 is a hollow disc-shaped sheet member, and is attached to the surface of the cap body 201 facing the interchangeable lens 100 so as to cover the two sets of magnets 202 and the yoke 203 mounted inside the cap body 201. The effects of attaching the flocked paper 204 to the surface of the cap body 201 facing the interchangeable lens 100 are as follows. The flocked paper 204 conceals the two sets of magnets 202 and the yoke 203 mounted inside the cap body 201 and the traces of gluing them to the inside of the cap body 201. The flocked paper 204 protects the contact surface that comes into contact with the tip of the interchangeable lens 100 and the lens cap holder. The flocked paper 204 improves the quality of attachment of the lens cap 200 to the tip of the interchangeable lens 100 and the lens cap holder. The flocked paper 204 prevents the magnet 202 or yoke 203 from accidentally coming into contact with the front lens surface of the interchangeable lens 100 and damaging the lens surface if the magnet 202 or yoke 203 suddenly falls off the cap body 201.

On the surface of the cap body 201 facing the interchangeable lens 100, an inner diameter 201a is formed toward the center from the position where the two sets of magnets 202 and yoke 203 are arranged. The inner diameter 201a formed in the cap body 201 is approximately the same as the outer diameter of the protruding portion that protrudes toward the suction disk member formed around the hollow portion of the hollow disk-shaped holder disk member of the lens cap holder described below. This makes it possible to limit the movement of the lens cap 200 in the horizontal direction relative to the plane of the suction disk member when the lens cap 200 is suction-held to the lens cap holder.

Hereinafter, in the lens cap 200, the surface of the cap body 201 that faces the interchangeable lens 100 may be referred to as the back surface. The opposite side may be referred to as the front surface. That is, in the lens cap 200 of the reference example , the surface on which the flocked paper 204 is arranged is the back surface, and the surface on which the cap body 201 is arranged is the front surface.

Figure 4 is a cross-sectional view showing the lens cap 200 attached to the tip of the interchangeable lens 100.

In FIG. 4, as described above, two sets of magnets 202 and yokes 203 are mounted inside the cap body 201, which generate magnetic force and are attracted to the attraction plate 101 at the tip of the interchangeable lens 100. This attraction force allows the lens cap 200 to be attached to the tip of the interchangeable lens 100.

On the back surface of the lens cap 200, the outer diameter of the cap body 201 and the inner diameter of the filter attachment portion 100a at the tip of the interchangeable lens 100 are approximately the same. As a result, when the lens cap 200 is attached to the interchangeable lens 100, the entire front lens surface of the interchangeable lens 100 is protected by the cap body 201. In addition, movement of the lens cap 200 in a direction perpendicular to the optical axis can be restricted.

Except for interchangeable lenses such as ultra-wide-angle lenses, which cannot have a lens cap or filter attached to their tips, a typical interchangeable lens 100 has an inner diameter at its tip for attaching a filter. It is preferable to use the inner diameter of this filter attachment section 100a to restrict the lens cap 200 from moving in a direction perpendicular to the optical axis. This makes it possible to make the outer diameter of the lens cap 200 more compact than if the lens cap 200 were configured to cover the entire tip of the interchangeable lens 100. If the inner diameter of the filter attachment section 100a is not used, a separate shape must be added to the interchangeable lens 100, which creates the problem of the outer diameter of the interchangeable lens 100 and lens cap 200 becoming larger.

On the back surface of the lens cap 200, flocked paper 204 is attached so as to conceal the two sets of magnets 202 and yoke 203 mounted inside the cap body 201. At the tip of the interchangeable lens 100, the front ring 102 is attached so as to cover the location where the suction plate 101 is attached. Therefore, when the lens cap 200 is attached to the interchangeable lens 100, the flocked paper 204 and the front ring 102 are interposed between the magnet 202 and the suction plate 101.

Figure 5 is an exploded perspective view showing the configuration of the lens cap holder in this embodiment.

In FIG. 5, 300 denotes the lens cap holder, 301 denotes the suction disk member, 302 denotes the holder disk member, and 303 denotes the double-sided tape.

The suction disk member 301 has a hollow disk shape and is made of a ferromagnetic material such as a metal having magnetic properties. When the lens cap 200 is attached to the lens cap holder 300, it is attracted to the suction disk member 301 by magnetic force.

A protrusion 301a is formed on a portion of the periphery of the suction disk member 301. The protrusion 301a serves as a part that supports the lens cap holder 300 when the lens cap 200 is removed from the lens cap holder 300.

The protrusion 301a can also be formed with a through hole 301b for passing a strap or the like through. Figure 6 is a perspective view showing the state in which a strap 304 is attached to the through hole 301b of the lens cap holder 300.

Figure 7 is a perspective view showing a modified example of a protrusion 301a formed on a part or the entire periphery of the suction disk member 301. The protrusion 301a may be formed with a continuous width from the periphery of the suction disk member 301 as shown in Figure 7 (a). Also, multiple protrusions 301a may be formed on the periphery of the suction disk member 301 as shown in Figure 7 (b). Furthermore, the protrusions 301a may be formed on the entire periphery of the suction disk member 301 as shown in Figure 7 (c).

The holder disk member 302 is a hollow disk like the suction disk member 301. The double-sided tape 303 is also a hollow disk like the suction disk member 301 and the holder disk member 302. The respective members are overlapped so that the central axes of the hollow portions 301c, 302a, and 303a of the hollow disk shape are aligned, and are bonded together with the double-sided tape 303 to form the lens cap holder 300.

In the present invention, the basic component of the lens cap holder, which includes a hollow, disk-shaped suction disk member made of a ferromagnetic material, is the holder base. The holder base of the present invention is also characterized in that a protrusion is formed around the hollow portion, protruding in a direction perpendicular to the plane of the holder base. In this embodiment, the component in which the suction disk member 301 and the holder disk member 302 are integrated by the double-sided tape 303 is the holder base of the present invention.

Figure 8 is a perspective view showing a modified example of the lens cap holder 300 of this embodiment in which a protrusion 301d is formed around the hollow portion 301c on one side of the suction disk member 301, protruding in a direction perpendicular to the plane of the suction disk member 301, and the suction disk member 301 serves as the holder base according to the present invention. As the holder base is composed only of the suction disk member 301, the number of components constituting the lens cap holder 300 can be reduced.

Figure 9 is a perspective cross-sectional view showing a modified example of the lens cap holder 300 of this embodiment in which protrusions 301d that protrude in a direction perpendicular to the plane of the suction disk member 301 are formed around the hollow portion 301c on both sides of the suction disk member 301 by outsert molding or the like using a synthetic resin material, and this is used as the holder base of the present invention. Since the holder base is composed of the suction disk member 301 with the protrusions 301d integrally molded therewith, the number of steps in assembling the lens cap holder 300 can be reduced. Also, since the protrusions 301d are molded to protrude on both sides in a direction perpendicular to the plane of the holder base, the lens cap 200 can be suction-held on both the front and back surfaces of the lens cap holder 300.

The holder disk member 302 is formed by injection molding using synthetic resin as the material. A protrusion 302b is formed around the hollow portion 302a of the holder disk member 302. The protrusion 302b may be formed only around the hollow portion 302a of the holder disk member 302 or around the hollow portion of the holder base according to the present invention, instead of the entirety. When the suction disk member 301 and the holder disk member 302 are adhered with double-sided tape 303, the protrusion 302b protrudes toward the suction disk member 301. When the lens cap 200 is suction-held by the lens cap holder 300, the protrusion 302b of the holder disk member 302 and the inner diameter 201a of the cap body 201 fit together.

It is preferable that the shape of the protruding portion 302b of the holder disk member 302 is made common to multiple types of lens caps 200. Multiple types of lens caps 200 can be adsorbed and held by the lens cap holder 300, and a single lens cap holder 300 can be carried when replacing and using multiple interchangeable lenses with different lens cap sizes.

Figure 10 is a cross-sectional view showing the lens cap 200 being held by suction on the lens cap holder 300.

In FIG. 10, as described above, two sets of magnets 202 and yokes 203 are mounted inside the cap body 201, which generate magnetic force and are attracted to the ferromagnetic attraction disk member 301 of the lens cap holder 300. This attraction force attracts and holds the lens cap 200 to the lens cap holder 300.

A protrusion 302b is formed around the hollow portion 302a of the holder disk member 302. The outer diameter of the protrusion 302b fits into the inner diameter 201a of the cap body 201 of the lens cap 200. This limits the movement direction of the lens cap 200 when attaching or detaching it to only the direction perpendicular to the plane of the suction disk member 301 of the lens cap holder 300.

The adhesive force between the lens cap holder 300 and the lens cap 200 acts only in a direction perpendicular to the plane of the adhesive disk member 301, and does not act in a direction horizontal to the plane of the adhesive disk member 301. In a direction horizontal to the plane of the adhesive disk member 301, a holding force due to friction between the planes of the flocked paper 204 and the adhesive disk member 301 acts. However, the holding force due to friction is weaker than the adhesive force due to magnetic force, and there is a risk that it will be easily released by external forces such as vibration or impact. In particular, when the flocked paper 204 is interposed between the lens cap holder 300 and the lens cap 200 of this embodiment, the holding force due to friction is even weaker.

If an external force such as vibration or impact exceeds the holding force due to friction, the positions of the two sets of magnets 202 and yoke 203 and the attractive disk member 301 may become misaligned in a direction horizontal to the plane of the attractive disk member 301. If the distance between the two sets of magnets 202 and yoke 203 and the attractive disk member 301 increases, the attractive force weakens, causing the lens cap 200 to come off the lens cap holder 300.

In the lens cap holder 300 and lens cap 200 of this embodiment, when the lens cap 200 is attracted and held by the lens cap holder 300, the outer diameter of the protrusion 302b of the holder disk member 302 fits into the inner diameter 201a of the cap body 201. This keeps the horizontal positions of the two sets of magnets 202, yoke 203, and attracting disk member 301 from changing, and maintains the magnetic attraction force of the two sets of magnets 202, yoke 203, and attracting disk member 301. This prevents the lens cap 200 from falling off the lens cap holder 300.

Figure 11 is a perspective cross-sectional view showing how to remove the lens cap 200 from the lens cap holder 300.

In FIG. 11, as described above, the suction disk member 301 and the holder disk member 302 are hollow disk-shaped, and the lens cap holder 300, which is formed by bonding these together, also has a hollow disk shape.

Hereinafter, the surface of the lens cap holder 300 on which the lens cap 200 is not attached may be referred to as the back surface. In other words, in the lens cap holder 300 of this embodiment, the surface on which the holder disc member 302 is arranged is the back surface.

When the lens cap 200 is held by suction on the lens cap holder 300, the lens cap holder 300 has a hollow disk shape, so the back surface of the lens cap 200 is exposed at the back surface of the lens cap holder 300. When removing the lens cap 200 from the lens cap holder 300, the user can insert a finger into the hollow portion from the back surface of the lens cap holder 300 and apply a pushing force A to the back surface of the lens cap 200 with the finger. At the same time, the user can apply a supporting force B to the protruding portion 302b of the suction disk member 301 with another finger or the like. As a result, when the force acting between the lens cap holder 300 and the lens cap 200 to pull them apart exceeds the suction force caused by the magnetic force, the lens cap 200 can be removed from the lens cap holder 300.

A recess 201b is formed on the outer periphery of the cap body 201 of the lens cap 200. The recess 201b is shaped mainly for removing the lens cap 200 from the tip of the interchangeable lens 100. When removing the lens cap 200 from the lens cap holder 300, the user can also hook the finger on the recess 201b to remove the lens cap 200 from the lens cap holder 300. However, in this case, it is necessary to apply a balanced force to the recess 201b on the outer periphery of the cap body 201, so multiple fingers must be hooked on the recess 201b at the same time. Therefore, the protrusion 301a of the suction disk member 301 must be supported with the other hand, and the user must remove the lens cap 200 from the lens cap holder 300 with both hands.

In the lens cap holder 300 and lens cap 200 of this embodiment, the user can insert a finger into the hollow portion from the back of the lens cap holder 300, and apply force A to a single point at the center of the lens cap 200, thereby applying a balanced force to the entire lens cap. This allows the user to stably remove the lens cap 200 from the lens cap holder 300 with a simple operation. For example, the user can insert his middle finger or index finger into the hollow portion from the back of the lens cap holder 300, apply force A to a single point at the center from the back of the lens cap 200, and at the same time support the protrusion 301a of the suction disk member 301 with force B with his thumb, thereby removing the lens cap 200 from the lens cap holder 300 with one hand.

According to the lens cap holder of the present invention, the lens cap can be prevented from being lost during shooting, and the lens cap can be attracted to and held by the lens cap holder so as not to interfere with camera operation during shooting. The lens cap can be removed from the lens cap holder with a simple operation. The lens cap can be prevented from easily falling off from the lens cap holder. The lens cap can be easily removed from the lens cap holder. At least two sets of magnets and yokes arranged inside and along the circumference of the cap body of the lens cap can be concealed, preventing the lens cap from falling off from the cap body. The quality of attachment of the lens cap to the tip of the lens barrel or to the lens cap holder can be improved.

REFERENCE SIGNS LIST 100 Interchangeable lens 101 Suction plate 102 Front ring 100a Filter attachment portion 200 Lens cap 201 Cap body 201a Inner diameter 201b Recessed portion 202 Magnet 203 Yoke 204 Flocked paper 300 Lens cap holder 301 Suction disk member 301a Projection 301b Through hole 301c Hollow portion 301d Protruding portion 302 Holder disk member 302a Hollow portion 302b Protruding portion 303 Double-sided tape 303a Hollow portion 304 Strap

Claims (2)

A lens cap holder has a recess in the center and magnetically attracts and holds a lens cap attached to the tip of a lens barrel,
a hollow disk-shaped holder base including a hollow disk-shaped attraction disk member made of a ferromagnetic material;
a protrusion is formed around the hollow portion of the holder base, the protrusion protruding in a direction perpendicular to a plane of the holder base ;
the protrusion is capable of fitting into an inner diameter of the recess of the lens cap,
The hollow portion has a size that allows a finger to be inserted therein,
The holder base has a protrusion on a part of its periphery,
A lens cap holder characterized in that, when removing the magnetically attracted lens cap, a pressing force is applied to the recess by the user's first finger inserted through the hollow portion, and at the same time, a supporting force is applied to the protrusion by the user's second finger . 2. The lens cap holder according to claim 1, wherein the pressing force and the supporting force act in opposite directions.

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