JP5463651B2 - Camera, camera accessories - Google Patents

Description

  The present invention relates to a camera and a camera accessory.

A bayonet type mount or the like is known as a mount mechanism for fastening a camera and a camera accessory such as an interchangeable lens (see, for example, Patent Document 1).
JP-A-9-21645

In recent years, cameras and camera accessories tend to be further miniaturized, and a mount mechanism for fastening them is also desired to be miniaturized.
An object of the present invention is to provide a miniaturized camera and camera accessory.

The present invention solves the above problems by the following means.
The invention of claim 1 is provided in a mount portion having a mount opening through which subject light passes, and mechanically engages with an accessory-side mount portion provided in an accessory attached to the mount portion. A restriction part for restricting relative movement of the subject light in the optical axis direction between the accessory-side mount part and the mount part, a front decoration ring integrally formed with the restriction part , a flange back provided on the mount part, A reference surface portion that defines a length, wherein the mount portion includes the reference surface portion housed in a camera housing, and the position of the reference surface portion is limited in the optical axis direction. parts and overlap position or the said object light than limiting portion is Ri position der image plane side of the imaging, the front decorative ring, camera der, characterized in that does not function as a reference plane .

A second aspect of the present invention, in the camera according to claim 1, wherein the mounting unit is a camera, which is a bayonet mount provided with a plurality of claw portions as the restricted portion.
A third aspect of the present invention, in the camera according to claim 1 or claim 2, wherein the reference plane portion may be provided in the center side area of the optical path of the limiting portion by remote the object light it is a camera.

According to a fourth aspect of the present invention, there is provided a camera accessory comprising a bayonet-type accessory-side mount that can be attached to and detached from the camera mount according to any one of the first to third aspects. The side mount portion restricts relative movement in the optical axis direction between the accessory side mount portion and the camera mount portion when the accessory side mount portion is engaged with the camera mount portion. An accessory-side restriction portion and an accessory-side reference surface portion that abuts the reference surface portion of the camera in the engaged state are provided, and the arrangement position of the reference-side portion on the accessory side is the optical axis In the direction, the position overlaps with the restriction part on the accessory side, or the position on the camera side with respect to the restriction part on the accessory side. It is an accessory for the camera to be a butterfly.
In addition, the said structure may be improved suitably, and at least one part may substitute for another structure.

  According to the present invention, it is possible to provide a miniaturized camera and camera accessory.

Hereinafter, a camera body and a lens barrel, which are embodiments of a camera and a camera accessory to which the present invention is applied, will be described with reference to the drawings and the like.
FIG. 1 is a perspective view showing a camera body and a lens barrel of the embodiment.
FIG. 2 is a view showing a mount portion provided in the lens barrel shown in FIG.
FIG. 3 is a cross-sectional view including the optical axes of the camera and lens barrel shown in FIG.
3A and 3B show states before and after the lens barrel is mounted on the camera body, respectively.
In order to facilitate understanding, a three-dimensional coordinate system composed of an X axis, a Y axis, and a Z axis is set in each drawing.

The camera body 1 and the lens barrel 2 form an interchangeable lens camera system.
The camera body 1 includes a housing 10, a mount unit 20, an imaging unit 30 (see FIG. 3), a barrier device 40, and the like.
The housing 10 is a portion that forms the external appearance surface of the camera body 1, and is formed in a substantially rectangular parallelepiped box shape by a metal material or a synthetic resin material, for example.
A circular opening (hereinafter referred to as a housing opening 11) is formed in the front surface of the housing 10 in a front view (see FIG. 3). Subject light traveling from the lens barrel 2 toward the camera body 1 passes through the housing opening 11 and is guided to an imaging unit 30 described later. In addition, the front part of the camera body 1 means a surface part that faces the subject at the time of photographing among the surface parts of the camera body 1. A liquid crystal display device 12 that displays a captured image or a through image is provided on the rear surface of the housing 10.

The mount portion 20 forms a part of a mount mechanism that fastens the camera body 1 and the lens barrel 2. Details of the mount unit 20 will be described in detail later.
The imaging unit 30 converts the subject light guided by the photographing lens 60 provided in the lens barrel 2 into an electrical signal and outputs the electrical signal, and the subject image formed on the imaging surface of the imaging device 31. An optical low-pass filter 32 (LPF 32) that suppresses the occurrence of moiré, a dust removal unit 33 that vibrates a diaphragm provided to face the incident surface of the LPF 32, and removes dust adhering to the diaphragm are provided. (See FIG. 3).
The barrier device 40, for example, closes the mount opening 21a formed in the mount portion 20 when the lens barrel 2 is not attached, and prevents dust from entering the inside of the housing 10.

Next, the structure of the mount part 20 provided in the camera body 1 will be described.
The mount portion 20 is a bayonet-type mount including a mount base portion 21, a front decoration ring 22, a claw portion 23, a pressing spring 24, a reference surface defining portion 25, an engagement groove 26, a latch pin 27, an electrical contact 28, and the like ( (See FIG. 3 for the holding spring 24).
The mount base 21 is a plate-like member made of, for example, a synthetic resin material, and is fixed to the inner side surface of the housing 10. The mount base 21 is provided so as to protrude from the peripheral edge of the housing opening 11 formed in the front portion of the housing 10 to the inner diameter side thereof, and is mounted at the center of the mount opening through which subject light passes. A portion 21a is formed.

  The front decoration ring 22 is an annular member that extends along the peripheral edge of the housing opening 11 and is formed of, for example, a metal material. The front decoration ring 22 is fixed to the mount base 21 with screws V1. The front decoration ring 22 has a function of improving the appearance quality of the camera body 1 by making the peripheral edge of the housing opening 11 invisible from the outside.

When the lens barrel is mounted on the camera body 1, the claw portion 23 is mechanically engaged with a claw portion 72 provided on the mount portion 70 of the lens barrel 2 described later, thereby The relative movement of the lens barrel 2 in the optical axis direction is limited.
The claw portion 23 is formed integrally with the front decoration ring 22 and is formed to protrude from the inner peripheral surface of the front decoration ring 22 to the inner diameter side of the front decoration ring 22, at substantially equal intervals around the optical axis, For example, three are provided.

  The holding spring 24 is a leaf spring arranged to face the surface portion of the claw portion 23 facing the imaging unit side, and as shown in FIG. 1, even when the camera body 1 is viewed from the front, it cannot be visually recognized. It is like that. The holding spring 24 presses the claw portion 72 provided in the mount portion 70 of the lens barrel 2 to the optical axis direction photographer side (imaging unit side) in a state where the lens barrel 2 is mounted on the camera body 1. As a result, backlash in the optical axis direction between the lens barrel 2 and the camera body 1 is suppressed.

The reference surface defining portion 25 is, for example, a plate-like member formed in an annular shape from a metal material, and is fixed to the mount base 21 with screws V2. The reference surface defining portion 25 is disposed on the inner diameter side of the front decoration ring 22 in a front view.
The surface portion facing the subject side in the optical axis direction in the reference surface defining portion 25 functions as a reference surface portion that defines the flange back length (hereinafter, this surface portion is referred to as a reference surface portion 25a). Here, in this specification, the flange back length is a distance from the imaging surface of the image sensor 31 to the reference surface portion 25a of the reference surface defining portion 25 (indicated by reference numeral F in FIG. 3A). Shall mean.
The engagement groove 26 is a groove formed in the mount base 21, extends along the inner peripheral edge of the reference surface defining portion 25, and its center substantially coincides with the optical axis.

The latch pin 27 is formed to protrude from the reference surface portion 25a of the reference surface defining portion 25 toward the subject side in the optical axis direction. The latch pin 27 is fitted into a latch hole 74 provided in the mount portion 70 of the lens barrel 2 in a state in which the lens barrel 2 is mounted on the camera body 1, whereby the lens barrel 2 and the camera body 1. And limit relative rotation around the optical axis.
The latch pin 27 is movable between a protruding position (see FIG. 1) protruding from the reference surface portion 25a and an accommodation state accommodated in the mount base 21, and is urged to a protruding position by a spring (not shown). Yes. A latch pin operation button 27a is provided on the front surface of the housing 10, and the latch pin 27 can be moved to the accommodated state by pushing the latch pin operation button 27a.

The electrical contact 28 electrically connects the camera body 1 and the lens barrel 2 and is provided in the mount portion 70 of the lens barrel 2 in a state where the lens barrel 2 is attached to the camera body 1. It contacts the electrical contact 75 (see FIG. 2). For example, nine electrical contacts 28 are provided along the peripheral edge of the mount opening 21a. The camera body 1 supplies power to the lens barrel 2 using a part of these contacts, and performs electrical communication with the lens barrel 2 using the other part of the contacts.
The electrical contact 28 is formed in a pin shape, and is provided so as to protrude from the region on the inner diameter side of the engagement groove 26 in the surface portion of the mount base 21 facing the subject in the optical axis direction toward the subject in the optical axis direction. The electrical contact 28 is a movable contact (see FIG. 3) that can move between a protruding position protruding from the mount base 21 and an accommodation state accommodated in the mount base 21, and is biased to the protruding position by a spring (not shown). Has been.

Here, the arrangement positions in the optical axis direction of the claw portion 23 of the mount portion 20 and the reference surface portion 25a provided in the camera body 1 will be described.
In FIG. 3A, a description will be given by adding a reference symbol A to the arrangement position of the claw portion 23 in the optical axis (Z-axis) direction and a reference symbol B to the arrangement position of the reference surface portion 25a in the optical axis direction. The arrangement position B of the reference surface portion 25a in the optical axis direction is closer to the imaging surface side of the image sensor 31 than the arrangement position A of the claw portion 23 in the optical axis direction.

Next, the configuration of the lens barrel 2 will be described.
The lens barrel 2 is an example of a camera accessory that is detachably attached to the camera body 1 and includes a barrel main body 50, a photographing lens 60, a mount 70, and the like.
The lens barrel main body 50 is formed in a cylindrical shape from, for example, a synthetic resin material.
The photographic lens 60 is an optical system that guides subject light to the image sensor 31 provided in the camera body 1, and is housed inside the barrel main body 50. The taking lens 60 is formed by a plurality of lens groups, and a part of them functions as a zoom lens and a focus lens.

The mount 70 forms the other part of the mount mechanism that fastens the camera body 1 and the lens barrel 2, and is provided at the end of the lens barrel main body 50 on the camera body side in the optical axis direction. Details of the mount 70 will be described in detail later.
A lens barrel 2 shown in each drawing including FIG. 1 is an example of a lens barrel that can be attached to the camera body 1, and the camera body 1 has a mount portion having substantially the same configuration as the lens barrel 2. A plurality of types of lens barrels equipped with can be selectively mounted.

Hereinafter, the structure of the mount part 70 provided in the lens barrel 2 will be described.
The mount portion 70 of the lens barrel 2 has a shape corresponding to the mount portion 20 of the camera body 1, and includes a mount base 71, a claw portion 72, an engagement protrusion 73, a latch hole 74, an electrical contact 75, and the like. ing.
The mount base 71 is a disk-shaped portion that closes the opening on the optical axis direction camera body side of the lens barrel main body 50, and an opening for allowing subject light to pass through is formed at the center. Yes. The diameter of the mount base 71 is set smaller than the diameter of the lens barrel main body 50.

  The claw portion 72 is formed so as to protrude from the outer peripheral surface of the mount base 71 to the outside in the radial direction of the lens barrel 2. For example, three claw portions 72 are provided at substantially equal intervals around the optical axis. The diameter of the circle defined by the tip portions of the three claw portions 72 is substantially the same as the diameter of the lens barrel main body portion 50.

The engagement protrusion 73 is an annular portion formed to protrude from the surface portion of the mount base 71 facing the camera body side to the camera body 1 side, and its center substantially coincides with the optical axis. . The engagement protrusion 73 fits into the engagement groove 26 provided in the mount portion 20 of the camera body 1 in a state where the lens barrel 2 is mounted on the camera body 1.
Only a minute gap is formed between the engagement protrusion 73 and the engagement groove 26 so as to allow such sliding in the fitted state shown in FIG. In this fitted state, relative rotation about the optical axis between the lens barrel 2 and the camera body 1 is allowed, but relative movement in the radial direction between the lens barrel 2 and the camera body 1 is limited. As described above, the engagement protrusion 73 and the engagement groove 26 function as a positioning mechanism that cooperates to define the radial mounting position of the lens barrel 2 with respect to the camera body 1.

  Here, of the surface portion facing the camera body 1 side of the mount base 71, the region 71 a on the outer diameter side of the engagement protrusion 73 is the state of the camera body 1 in a state where the lens barrel 2 is attached to the camera body 1. It comes into contact with a reference surface portion 25 a provided on the mount portion 20 and functions as a reference surface portion of the lens barrel 2. Hereinafter, this region is referred to as a reference surface portion 71a. The surface portion of the claw portion 72 facing the camera body side and the reference surface portion 71a are disposed in the same plane orthogonal to the optical axis O.

The latch hole 74 is a portion into which the latch pin 27 provided in the mount portion 20 of the camera body 1 is inserted, and is formed in a surface portion of the mount base portion 71 facing the camera body side in the optical axis direction.
The electrical contact 75 is a fixed contact that is fixed to the mount base 71, and a position that contacts the electrical contact 28 provided on the mount unit 20 of the camera body 1 in a state where the lens barrel 2 is mounted on the camera body 1. Is provided.

Here, the arrangement positions of the claw part 72 of the mount part 70 and the reference surface part 71a provided in the lens barrel 2 in the optical axis direction will be described.
The mount part 70 has a configuration corresponding to the mount part 20 of the camera body 1.
As described above, the mount part 20 on the camera body side is provided with the reference surface part 25a closer to the imaging unit 30 than the claw part 23. Therefore, the claw part 72 and the reference surface part 71a of the mount part 70 of the lens barrel 2 are provided. Corresponding to this, as shown in FIG. 3, the lens barrel 2 is disposed on the image plane side with respect to the claw portion 23 on the camera body 1 side in the mounted state.

The mount portion 20 of the camera body 1 and the mount portion 70 of the lens barrel 2 in this embodiment are a kind of bayonet type mount mechanism, and the mounting procedure of the lens barrel 2 to the camera body 1 is a known bayonet type mount mechanism. Is almost the same.
That is, after the camera body 1 and the lens barrel 2 are relatively moved in the optical axis direction and the claw portion 72 of the lens barrel 2 is inserted between the claw portions 23 of the camera body 1, the lens barrel 2 and the camera are inserted. The body 1 is rotated relative to the optical axis. As a result, the claw portion 72 is inserted between the claw portion 23 and the mount base portion 21 to restrict relative movement of the camera body 1 and the lens barrel 2 in the optical axis direction. Further, the latch pin 27 provided in the camera body 1 is inserted into the latch hole 74 provided in the lens barrel 2, and the lens barrel 2 and the camera body 1 are fastened. In this fastened state, the claw portion 72 is pressed against the reference surface portion 25a by the holding spring 24 fixed to the claw portion 23, and the reference surface portion 71a of the lens barrel 2 and the reference surface portion 25a of the camera body 1 are in close contact with each other. The play of the lens barrel 2 relative to the camera body 1 in the optical axis direction is suppressed.

Next, the effect of the mount mechanism of the embodiment will be described in comparison with the mount mechanism of the comparative form.
FIG. 4 is a diagram showing the comparison of the mount mechanism of the comparative form (FIG. 4A) and the mount mechanism of the embodiment (FIG. 4B).
4A is a well-known bayonet-type mount portion, and a reference surface portion 171a is provided closer to the subject side in the optical axis direction than the claw portion 172. The mount portion 170 provided in the comparative lens barrel 102 shown in FIG. It has been.

Here, for example, a motor M that drives a lens group for focusing, a CPU that controls the motor M, an image blur correction unit, and the like are accommodated in the lens barrel 102 (other than the motor is shown in the figure). (Omitted).
The conventional lens barrel 102 has a smaller radial dimension r in a region closer to the camera body than the reference surface portion 171a in order to form the reference surface portion 171a. Therefore, the region in which the motor M and the like can be substantially accommodated is limited to the region from the distal end portion on the subject side to the reference surface portion 171a (denoted by reference sign L in FIG. 4A).

  On the other hand, in the lens barrel 2 of the embodiment shown in FIG. 4B, the reference surface portion 71a is formed on the end surface on the camera body 1 side, and the radial dimension (diameter R) is the whole of the barrel. It is almost the same over. Therefore, compared with the lens barrel 102 of the comparative form, the motor M and the like can be arranged closer to the camera body 1 side. Accordingly, the lens barrel 2 of the embodiment can be reduced in size by reducing the overall length as compared with the lens barrel 102 of the comparative embodiment.

In addition, the mount portion 120 provided in the camera body 101 of the comparative form includes an annular front ornament ring 121 and a claw portion 122 that protrudes from the inner peripheral surface of the front ornament ring 121 toward the inner diameter side. ing. The mount 120 of this comparative embodiment functions as a reference surface 121a in which the surface of the front decoration ring 121 facing the subject in the optical axis direction defines the flange back length.
The width (a dimension in a direction parallel to the radial direction of the front ring) W1 of the reference surface portion 121a is a certain length (width) in order to stably and firmly fasten the camera body 101 and the lens barrel 102. Is required. In addition, the larger the width (contact area), the lower the contact pressure and the lower the wear resistance. As a result, the durability is improved.
On the other hand, since the front ornament ring 22 does not have a function as a reference surface portion, the mount portion 20 provided in the camera body 1 of the embodiment has a narrow width (reference numeral in FIG. 4B). (See W2), and the external appearance of the camera mount portion can be reduced.

Moreover, according to the camera body 1 of the embodiment, the following effects can be obtained.
(1) Since the camera body 1 of the embodiment includes the barrier device 40, it is not necessary to attach a body cap even when the lens barrel 2 is not attached.
Here, the conventional mount portion 120 provided in the camera body 101 of the comparative form is formed so that the reference surface portion 121a projects to the subject side with respect to the housing 110. Therefore, when the body cap is not attached, the reference surface portion 121a. It is easy to be damaged.
On the other hand, since the mount portion 20 of the present embodiment has the reference surface portion 25a housed inside the housing 10, the possibility of damage to the reference surface portion 25a is reduced without mounting a body cap. it can.
Also, if the barrier device 40 is not provided, it is necessary to attach a body cap. However, in the case of the mounting portion 120 of the comparative form, the outer diameter dimension of the body cap is approximately the same as the outer diameter dimension of the front decoration ring 121. Need to be formed.
On the other hand, in the mount portion 20 of the embodiment, since the reference surface defining portion 25 is disposed on the inner diameter side of the front decoration ring 22, the outer diameter of the body cap may be about the inner diameter dimension of the front decoration ring 22. Cap can be downsized.
(2) Since the front decoration ring 22 provided in the camera body 1 does not function as a reference surface portion, it is not necessary to form it with high dimensional accuracy. Further, since it is not necessary to bring the front decoration ring 22 and the lens barrel 2 into contact with each other, even if the front decoration ring 22 is painted, the coating is not peeled off by repeatedly attaching and detaching the lens barrel 2. In addition, designs such as engravings and irregularities can be formed on the front decoration ring 22.

[Deformation]
The present invention is not limited to the embodiment described above, and various modifications and changes as shown below are possible, and these are also included in the technical scope of the present invention.
(1) In the embodiment, the camera accessory attached to the camera is an interchangeable lens barrel provided with a photographing lens. However, the camera accessory is not limited thereto, and includes, for example, a conversion lens, a close-up ring, a body cap, and the like. It may be. Also, the type of camera is not particularly limited, and may be a still camera or a movie camera. Furthermore, in the case of a still camera, a single-lens reflex camera equipped with an optical viewfinder or a camera equipped with an electronic viewfinder may be used.
(2) In the lens barrel of the embodiment, the surface portion of the claw portion facing the camera body side and the reference surface portion form the same plane, but the arrangement position of the reference surface portion is not limited to this, and the optical axis direction As long as the position of the position overlaps the claw portion, the position may be a position closer to the tip than the embodiment. Further, the configuration of the mount portion on the camera body side may be a shape corresponding to this. Specifically, the arrangement position of the claw portion in the optical axis direction (see symbol A in FIG. 3A) and the arrangement position of the reference surface portion in the optical axis direction (see symbol B in FIG. 3A) overlap. May be.
(3) In the embodiment, the mount mechanism for fastening the camera body and the lens barrel is a bayonet type mount mechanism, but is not limited thereto, and may be, for example, a screw (screw-in) type mount. . In such a screw-type mount, the screw thread functions as a limiting portion. In the case of a bayonet mount, the bayonet mount is not limited to the three-claw type described in the embodiment, and may be a four-claw type, for example.
(4) In the camera body of the embodiment, an inner claw type having a claw portion protruding from the front ring to the inner diameter side is formed, but the claw portion may protrude to the outer diameter side (outside Nail type). Further, when the outer claw type is used as described above, the reference surface portion may be arranged on the outer diameter side of the claw portion.

It is a perspective view which shows the camera body and lens barrel of embodiment. It is a perspective view which shows the mount part of the lens-barrel shown in FIG. It is sectional drawing containing the optical axis of the camera body and lens barrel shown in FIG. It is a figure which compares and shows the mount mechanism of embodiment and a comparison form.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Camera body: 2 Lens barrel: 20 Mount part 21a Mount opening: 23 nail part: 25a Reference surface part: 70 Mount part: 71a Reference surface part: 72 Nail part

Claims (4)

The accessory-side mount portion and the mount are provided in a mount portion having a mount opening through which subject light passes, and mechanically engaged with an accessory-side mount portion provided in an accessory attached to the mount portion. A limiting unit that limits relative movement of the subject light in the optical axis direction with respect to the unit,
A front decorative ring integrally formed with the restriction portion;
A reference surface provided on the mount and defining a flange back length;
A camera comprising:
The mount portion has the reference surface portion housed in a camera housing,
Position of the reference surface, in the optical axis direction, a position overlapping the limiting portion, or wherein the subject light than limiting portion is Ri position der image plane side of the imaging,
The front decoration ring does not function as a reference plane . The camera of claim 1,
The camera according to claim 1, wherein the mount part is a bayonet mount having a plurality of claw parts as the restricting part. The camera according to claim 1 or 2,
The camera according to claim 1, wherein the reference surface portion is provided in a region closer to the center of the optical path of the subject light than the restriction portion. A camera accessory comprising a bayonet-type accessory-side mount that is detachable from the camera mount according to any one of claims 1 to 3,
In the accessory side mount part,
An accessory side restricting portion for restricting relative movement of the accessory side mount portion and the mount portion of the camera in the optical axis direction in an engaged state of the accessory side mount portion with the mount portion of the camera; ,
In the engaged state, an accessory-side reference surface portion that contacts the reference surface portion of the camera;
Is provided,
The arrangement position of the reference surface part on the accessory side is a position that overlaps the restriction part on the accessory side in the optical axis direction or a position on the camera side with respect to the restriction part on the accessory side. Accessories for cameras.

Images