Accessory device

An accessory device of the present invention is configured to be mounted on an accessory shoe of an image pickup apparatus. The accessory device includes an insertion member configured to be inserted in an engagement space between a first engagement part and a second engagement part of the accessory shoe, an operating member configured to perform an operation for fixing the accessory device on the accessory shoe, and a moving member configured to move in a second direction intersecting with a first direction in which the insertion member is inserted in the engagement space. The moving member is provided with a protrusion part which is in contact with at least one of the first engagement part and the second engagement part so that the insertion member is not removed from the engagement space by a movement of the moving member in the second direction.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an accessory device such as a video light and a microphone, and more particularly to an accessory device equipped with a connection mechanism which is connected to and fixed on an image pickup apparatus such as a video camera.

2. Description of the Related Art

Conventionally, various types of connection mechanisms which are configured to connect an external accessory device to an accessory shoe of a camera main body (hereinafter referred to as an “accessory shoe”) to be fixed have been proposed.

The connection mechanism connected to and fixed on the accessory shoe has a function as a communication means for communicating various kinds of signals with the camera main body, in addition to a mechanical function which fixes the accessory device itself on the camera main body. Therefore, in order to ensure a reliable communication path, with regard to the connection mechanism of the accessory device, the connection position relation with the accessory shoe with high accuracy needs to be maintained.

In order to prevent the connection state between the connection mechanism of the accessory device and the accessory shoe from easily being released, for example, the following configuration is adopted as a connection mechanism.

First, in order to perform a positioning of the accessory device, a locking pin which can be removably inserted into a joint hole formed on the accessory shoe is provided. Second, a shoe locknut which sets a firm fixing state is provided by the screw connection with respect to a shoe base provided on the lower part of the accessory device which constitutes the connection mechanism and by moving in an upward and downward direction by rotation to fasten the accessory shoe.

FIG. 17shows a main cross-sectional view of a connection mechanism in a conventional accessory device.

InFIG. 17, shoe locknut3is connected by a screw with respect to a shoe base2fixed on a lower part of a main body1of an accessory device. The shoe locknut3itself moves in an upward and downward direction by rotation of the shoe locknut3.

A locking pin4inserted into a joint hole formed on an accessory shoe (not shown) is provided movably in an upward and downward direction in a through hole which is configured to pass through the shoe base2in an upward and downward direction. One end part4ais connected to one end part5aof a spring5in the main body1.

A base part5bof the spring5is fixed on the main body1and always biases the locking pin4in a direction where the other end part4bprotrudes outside the shoe base2, i.e. in a direction where the other end part4bprotrudes outside the shoe base2and is inserted into an engagement hole formed on the accessory shoe.

A protrusion6passes through a lower part of the main body1and is positioned between the shoe locknut3and the spring5. One end part6aof the protrusion6protrudes outside the main body1in accordance with the relation of the position where it is in contact with an upper end surface of the shoe locknut3. The other end part6bof the protrusion6is provided so as to be in contact with the spring5. When the shoe locknut3is rotated so as to move in an upward direction for releasing the connection, the upper end surface is in contact with the one end part6aof the protrusion6.

When the shoe locknut3is further rotated so as to move in the upward direction in this contact state, the protrusion6presses the spring5against its biasing force via the other end part6bin the upward direction. The locking pin4connected to the one end part5aof the spring5moves in the upward direction by the spring5pressed in the upward direction. As a result, the joint with the joint hole which is formed on the accessory shoe is released.

On the other hand, when the shoe locknut3is rotated in a direction opposite to the case described above, the shoe locknut3moves in a downward direction.

The spring5moves the protrusion6and the locking pin4in the downward direction by its elastic force. Therefore, the one end part4bof the locking pin4is protruded outside the shoe base2and is inserted into the joint hole formed on the accessory shoe (not shown). Thus, the position relationship between the accessory device and the camera main body is set in a specific state.

In this case, in accordance with the movement of the above shoe locknut3in the downward direction, a part of the accessory shoe (not shown) is clipped by the shoe base2to be fastened. Therefore, the shoe base2is fixed on the accessory shoe and the accessory device is firmly fixed on the camera main body.

In other words, the locking pin4moves in the upward and downward direction via the elastic force of the spring5in conjunction with the movement of the shoe locknut3in the upward and downward direction. Therefore, the accessory device is positioned with respect to the camera main body by the locking pin4and the joint hole formed on the accessory shoe.

Reference numeral7denotes a plurality of signal pins which are electrically connected to each kind of signal terminals formed on the accessory shoe (not shown).

On the other hand, since the shoe locknut3rotates to move in the upward direction and an end surface of the shoe locknut3is in contact with an end surface of the main body1, further rotation of the shoe locknut3is limited.

When a rotational force which moves the shoe locknut3in the upward direction is further added to the shoe locknut3, a bite unnecessary for the screw connection between the shoe locknut3and the shoe base2may occurs. If the bite unnecessary for the screw connection occurs, the shoe locknut3can not rotate there and it may take a long time for the release of the rotation disable state in the next movement in the downward direction.

In order to avoid such an inconvenience, for example, the configuration of a stopper mechanism as disclosed in Japanese Examined Utility Model Application Publication No. 57-29045 has been proposed. This stopper mechanism (not shown) has the following configuration. In other words, it includes a C-shaped groove formed on either one of an end surface of the facing shoe locknut and an end surface of the main body1(a groove that is planarly formed in a C-shape where a circumferentially-formed groove is partially blocked) and a protrusion provided on the end surface of the other one. Here, when the end surface of the shoe locknut gets close to the end surface of the main body1, the rotation of the shoe locknut stops by contact of the protrusion on an end wall part in the C-shaped groove.

By the way, according to the connection mechanism in the conventional accessory device shown inFIG. 17, the accessory device and the camera main body can maintain the relationship of the connection position with high accuracy and can be firmly connected to each other.

However, since each of the locking pin4, the spring5, and the protrusion6is an independent part, a plane area to some extent is necessary for the arrangement of the parts and the miniaturization of the connection mechanism is limited.

Since the locking pin4and the like are independent parts, the influence of the variation in size of each of the parts is large. For example, it is difficult to maintain the operating position of the shoe locknut3that is an operating member and the moving state of the locking pin4to be in a desired relation with high accuracy.

Furthermore, if the configuration for avoiding the bite as disclosed in Japanese Examined Utility Model Application Publication No. 57-29045 attempts to be provided as it is, it is necessary to ensure an arrangement space for the protrusion6or a protrusion which is in contact with an end surface of a C-shaped groove between an end surface of the shoe locknut3and an end surface of the main body1.

Accordingly, as described above, in conjunction with the need of the plane area to some extent, the shape of the connection mechanism may grow in size. Therefore, it was a large problem in view of the miniaturization of devices.

On the other hand, Japanese Patent Laid-Open No. discloses that the operation of moving up and down of the locking pin is performed using a cam. However, in this configuration, a cam member other than the shoe locknut needs to be prepared. Therefore, the number of the parts can not be drastically reduced.

BRIEF SUMMARY OF THE INVENTION

The present invention provides an accessory device which is equipped with a highly reliable connection part. The present invention also provides an accessory device which is configured to be reliably connected to an accessory shoe with a simple configuration.

An accessory device as one aspect of the present invention is configured to be mounted on an accessory shoe of an image pickup apparatus. The accessory device includes an insertion member configured to be inserted in an engagement space between a first engagement part and a second engagement part of the accessory shoe, an operating member configured to perform an operation for fixing the accessory device on the accessory shoe in a state where the insertion member is inserted in the engagement space, and a moving member configured to move in a second direction intersecting with a first direction in which the insertion member is inserted in the engagement space by the operation of the operating member. The moving member is provided with a protrusion part which is in contact with at least one of the first engagement part and the second engagement part so that the insertion member is not removed from the engagement space by a movement of the moving member in the second direction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Exemplary embodiments of the present invention will be described below with reference to the accompanied drawings.

FIG. 1is an appearance view of a video camera in the present embodiment. In the present embodiment, the video camera is shown as one example of an image pickup apparatus. In the description of the present embodiment, with regard to components at a side of the video camera, each name will be preceded by the words “camera side”. On the other hand, with regard to components at a side of the accessory device, each name will be preceded by the words “accessory side”.

InFIG. 1, reference numeral100denotes a video camera main body. Reference numeral101denotes a camera side engagement plate. Reference numeral102denotes a camera side contact holding member. The detail of the configuration, the function, and the like, of the camera side engagement plate101and the camera side contact holding member102will be described later.

FIG. 2is an exploded perspective view of an accessory shoe in the present embodiment.FIGS. 3 to 5are perspective views of the accessory shoe in an assembling completed state.FIG. 3is a perspective view of the accessory shoe when viewed from a front side.FIG. 4is a perspective view of the accessory shoe when viewed from a back side.FIG. 5is a perspective view of the accessory shoe when viewed from underneath. Thus,FIGS. 3 to 5show the accessory shoe when viewed from different directions. The accessory shoe is attached to the video camera main body100in a state as shown inFIGS. 3 to 5.

FIG. 6shows a cross-sectional view of the accessory shoe in the present embodiment. In the following description of the present embodiment, the left side direction of the cross section inFIG. 6is referred to as a “front”, and the right side direction inFIG. 6is referred to as a “back”. The “front” indicates an object direction of the video camera main body100or a mounting direction (at a mounting side) in which the accessory device is slidable to be mounted on the video camera main body100.

InFIGS. 1 to 6, reference numeral101denotes a camera side engagement plate as an engagement member. The camera side engagement plate101is made of a steel plate such as SPCC and SUS. The camera side engagement plate101is integrally formed by a punching process and/or a bending process.

Reference numeral102denotes a camera side contact holding member. The camera side contact holding member102is made of a thermoplastic resin material such as PBT and PA. Generally, the camera side contact holding member102is integrally formed by injection molding.

Reference numeral103denotes a camera side contact. The camera side contact103is made of a metal material such as phosphor bronze or copper-titanium alloy which has superior spring characteristics and conductivity, and is integrally formed by the punching process and/or the bending process. A surface treatment such as nickel plating or gold plating is performed on the camera side contact103. The camera side contact103is held by the camera side contact holding member102.

The camera side engagement plate101has a planar sliding part (a mounting base surface)101d. The camera side engagement plate101has a pair of camera side engagement parts (a first engagement part and a second engagement part)101aand101bwhich are positioned sandwiching a sliding space (an engagement space)101sthat is an upper side space of the sliding part101d.

First, the camera side engagement parts101aand101bare bent upward with respect to the sliding part101d. Next, the camera side engagement parts101aand101bbent upward is bent in parallel to the sliding part101dso that end parts of them are protruded into the inner side of the sliding space101s(so that the first engagement part and the second engagement part face each other).

Concave parts101uand101vare provided at each of inside end surfaces of the camera engagement parts101aand101b. A click feel is generated by an end part of a click spring605described later falling into the concave parts101uand101v.

In the following description of the present embodiment, an arrangement direction of the camera side engagement parts101aand101b(a direction in which the sliding space101sis sandwiched) is referred to as a shoe width direction.

A camera side engagement part (a third engagement part)101cis formed at a position anterior to the camera side engagement parts101aand101bof the camera side engagement plate101in a mounting direction (at a mounting side).

First, the camera side engagement part101cis bent upward with respect to the sliding part101d. Next, the camera side engagement part101cbent upward is bent in parallel to the sliding part101dso that an end part of it is protruded backward (in a direction opposite to the mounting direction, or so as to face the camera side engagement parts101aand101b).

An opening101eis formed under the camera side engagement part101cof the camera side engagement plate101. A front part of the camera side contact holding member102(hereinafter referred to as “a contact holding part102x”) is inserted from under the camera side engagement plate101into the opening101e.

Thus, the end part bent in parallel to the sliding part101dof the camera side engagement part101c(hereinafter referred to as “a bent end part”) and the contact holding part102xof the camera side contact holding member102are placed to face each other in an upward and downward direction.

An engagement space101twhich is connected to the sliding space101sis formed between the bent end part of the camera side engagement part101cand the contact holding part102xof the camera side contact holding member102. The contact holding part102xof the camera side contact holding member102and an upper surface of a camera side contact103held here (a contact part103adescribed later) are exposed inside the engagement space101tthrough the opening101efrom outside the engagement space101t.

A camera side connector (a connector at a side of an image pickup apparatus) which is electrically connected to an accessory side connector described later is constituted by the contact holding part102xof the camera side contact holding member102and the camera side contact103held here.

Positioning holes101fand101gand fixing screw holes101h,101i,101j, and101kare formed on the sliding part101dof the camera side engagement plate101. The positioning holes101fand101gperform a positioning of the camera side engagement plate101and the camera side contact holding member102by inserting protrusions102aand102bformed on the upper surface of the camera side contact holding member102from underneath. Screws111a,111b,111c, and111dfor fixing the camera side engagement plate101with respect to the video camera main body100are inserted into the fixing screw holes101h,101i,101j, and101kfrom above, respectively.

The camera side contact holding member102holds a plurality of camera side contacts103with the heights uniform in the shoe width direction at predetermined pitches for supplying power to the accessory device or for exchanging communication signals with the accessory device.

Partition walls are provided between adjacent camera side contacts103on the camera side contact holding member102. The partition walls prevent the adjacent camera side contacts103from shorting circuits.

As shown inFIG. 6, a contact engagement part102e, contact locking parts102fand102g, and a contact removal preventing part102kare formed on the contact holding part102xof the camera side contact holding member102. The contact engagement part102eholds the camera side contact103by engaging inside a crotch part103eon the camera side contact103formed in a biforked shape. The contact locking parts102fand102gengage with end parts103fand103gof contact parts103aand103bso as to hold the contact parts (two leg parts)103aand103bof the camera side contact103in a charge stage (an elastic deformation state).

The contact part103ais in contact with an accessory side contact603described later and communicates various kinds of signals with the accessory device. Therefore, the contact part103acan obtain a stable contact pressure (a biasing force) when it is in contact with the accessory side contact603by being charged in a non-contact state (an initial state) with the accessory side contact603.

On the other hand, the contact part103bis in contact with an FPC (a flexible printed board), which is not shown, at the side of the video camera main body100, and communicates various kinds of signals with the video camera main body100. Therefore, the contact part103bcan obtain a stable contact pressure (a biasing force) when it is in contact with the FPC by being charged in a non-contact state with the FPC.

The contact removal preventing part102khas a wedged cross sectional shape. It prevents the camera side contact103from falling from the camera side contact holding member102when the accessory device is attached or removed.

An upper surface102lof the camera side contact holding member102is in contact with a lower surface of the camera side engagement plate101. The upper surface102lis provided with the protrusions102aand102bdescribed above. A lower surface102mof the camera side contact holding member102is provided with positioning protrusions102cand102dwith respect to the video camera main body100.

Furthermore, the camera side contact holding member102is provided with fixing screw holes102h,102i,102j, and102k. The screws111a,111b,111c, and111ddescribed above are inserted into these fixing screw holes102h,102i,102j, and102k.

The upper surface102lof the contact holding part102xof the camera side contact holding member102is provided with guide wall surfaces102nand102o. The guide wall surfaces102nand102oare formed so as to sandwich a plurality of the contact parts103aof the camera side contacts103and the engagement space101tdescribed above in the shoe width direction and so as to extend them in a frontward and backward direction.

When an accessory side contact holding member601described later is inserted into the engagement space101tdescribed above, the guide wall surfaces102nand102oguide guide wall surfaces601nand601oof the accessory side contact holding part601. Thus, a displacement or a jounce between the camera side contact holding member102and the accessory side contact holding member601in the shoe width direction is avoided. In other words, the camera side contact103held by the camera side contact holding member102can be accurately in contact with the accessory side contact603corresponding to the camera side contact103, which is held by the accessory side contact holding member601.

FIG. 7is an exploded perspective view of a connection part (a shoe mounting part)600of the accessory device which is mounted on the accessory shoe of the present embodiment.FIGS. 8 to 10show the connection part600of the accessory device when viewed from different directions.FIGS. 8 and 9are perspective views of the connection part600of the accessory device when viewed from a front side.FIG. 10is a perspective view of the connection part600of the accessory device when viewed from underneath.

FIG. 11is a cross-sectional view of the connection part of the accessory device.FIG. 12is a cross-sectional view showing the state where the connection part (the shoe mounting part)600of the accessory device is mounted on the accessory shoe of the video camera main body100.

In the following description, a direction corresponding to a left side of the cross section ofFIGS. 11 and 12(a first direction) is referred to as a “front”, and a direction corresponding to a right side ofFIGS. 11 and 12(a second direction) is referred to as a “back”. Here, the “front” is a direction corresponding to an object direction for the video camera main body100(the first direction), and shows a mounting direction in which the connection part600of the accessory device slides to be mounted on the accessory shoe.

A video light or a flash light for illuminating the object, the microphone can be used for recording voices and be used for recording images, or a GPS device is used as the accessory device. The accessory device is not limited to this, and other accessory devices can also be used.

InFIGS. 7 to 11, reference numeral601denotes an accessory side contact holding member, and is made of a thermoplastic resin material such as PBT or PA. Generally, the accessory side contact holding member601is integrally formed by injection molding.

The accessory side contact holding member601(an insertion member) holds an accessory side contact603described later, and is configured to be inserted in a first direction with respect to the sliding space101sbetween a first engagement part and a second engagement part of the accessory shoe. The first direction is a direction in which the accessory device slides for connecting the accessory device with the accessory shoe. Therefore, the camera side engagement part (a third engagement part)101cis placed at a position anterior to the camera side engagement part (the first engagement part)101aand the camera side engagement part (the second engagement part)101bin the first direction.

Reference numeral602denotes an accessory side cover member, and similarly to the accessory side contact holding member601, is made of a thermoplastic resin material such as PBT or PA. Generally, the accessory side cover member602is integrally formed by injection molding.

Reference numeral603denotes an accessory side contact. The accessory side contact603is made of a metal material such as phosphor bronze or copper-titanium alloy which has superior spring characteristics and conductivity. The accessory side contact603is integrally formed by the punching process and/or the bending process. After that, a surface treatment such as nickel plating or gold plating is performed. The accessory side contact603is a contact for electrically connecting the video camera main body100(the image pickup apparatus).

Hereinafter, the configuration of the connection part600of the accessory device will be described in more detail.

The accessory side contact holding member601is provided with accessory side engagement parts601a,601b,601c, and601das well as a contact holding part601xwhich holds the accessory side contact603.

The accessory side engagement parts601aand601bare provided at the right and the left of the back part of the accessory side contact holding member601. Here, “the right and the left” is a direction corresponding to the shoe width direction described above. In the following description, this direction is referred to as an accessory width direction.

The accessory side engagement parts601aand601bare inserted between end parts of the camera side engagement parts101aand101bextending in parallel to the sliding part101d(hereinafter referred to as a “bent end part”) and the sliding part101d. The accessory side engagement parts601aand601bengage with the camera side engagement parts101aand101bby being inserted between the bent end parts of the camera side engagement parts101aand101band the sliding part101d.

Thus, the back part of the accessory side holding part601is held by the accessory shoe (the camera side engagement plate101), and the motion in the accessory width direction and the accessory height direction is limited.

The contact holding part601xis provided at a front part of the accessory side contact holding member601. The contact holding part601xis provided with partition walls for preventing adjacent accessory side contacts603from shorting circuit and holds the accessory side contacts603at predetermined pitches in the accessory width direction.

Guide wall surfaces601nand601oare formed on both side surfaces of the contact holding part601xin the accessory width direction. The guide wall surfaces601nand601oare wall surfaces which straight extend from a position where the accessory side engagement parts601aand601bare formed to the front. In other words, the guide wall surfaces601nand601oextend in a front direction with a predetermined width in parallel to the guide wall surfaces of the accessory side engagement parts601aand601bin the accessory width direction.

Furthermore, accessory side engagement parts601cand601dare formed on an upper part of both sides in the accessory width direction of the contact holding part601xwhich sandwiches the plurality of accessory side contacts603. The accessory side engagement parts601cand601dare inserted in an engagement space101tformed under the camera side engagement part101cwith the contact holding part601xand engage with the camera side engagement part101c.

As described above, an accessory side connector is constituted by the contact holding part601xand the accessory side contact603, and the front part of the accessory side contact holding part601is held by the accessory shoe (the camera side engagement plate101).

A concave part601zis formed on the lower surface at the front side of the accessory side contact holding member601. The concave part601zis provided with a plurality of holes601vwhich expose contact parts603aof the plurality of accessory side contacts603.

A pair of convex parts601uis formed on the upper surface at a back end of the accessory side contact holding member601. When the connection part600of the accessory device attempts to be inserted in a direction opposite to a correct direction with respect to the camera side engagement plate101, the insertion is prevented by contact on hack edge surfaces of the camera side engagement parts101aand101b.

The accessory side cover member602is attached to the accessory side contact holding member601so as to cover upper surfaces of the contact holding part601xand the accessory side contacts603. The accessory side cover member602protects the accessory side contacts603and prevents the accessory side contacts603from being removed.

The accessory side contact603is provided with a contact part603awhich is in contact with the camera side contact103(the contact part103a) at one end, and is provided with a contact part603bwhich is in contact with an FPC604described later at the other end. The accessory side contact603is in contact with the FPC604described later and has a role of supplying power to a control board inside the accessory device and exchanging communication signals. The contact part603ais in contact with the contact part103adescribed above at a predetermined contact pressure, and the contact part603bis in contact with the FPC604at a predetermined contact pressure.

The FPC604supplies a power supply voltage supplied from a side of the video camera main body100to a control board (not shown) provided in the accessory device, and exchanges communication signals between the control board and the video camera main body100.

Reference numeral605denotes a substantially M-shaped click spring. The click spring605is made of a metal material such as SUS or beryllium copper which has superior spring characteristics, and is integrally formed by the punching process and/or the bending process. The click spring605is stored in a storage part601yprovided at the accessory side contact holding member601. The lower end part of the click spring605is protruded to the upper parts of the accessory side engagement parts601aand601bthrough an opening601tformed on the lower surface of the storage part601y.

When the connection part600of the accessory device is mounted on (inserted in) the accessory shoe, the click spring605is in contact with the end surfaces of the bent end parts of the camera side engagement parts101aand101band is elastically deformed to slide on the inner end surface.

When the connection part600of the accessory device is inserted up to a predetermined mounting position with respect to the accessory shoe, a click feel is generated by falling the click spring605into the concave parts101uand101vprovided in the vicinity of the camera side engagement parts101aand101b. Therefore, a user can recognize that the connection part600of the accessory device is inserted up to a predetermined position with respect to the accessory shoe, and a mounting error can be avoided.

Reference numeral606denotes a locking member (a moving member). The locking member606is made of a thermoplastic resin material such as PC or ABS, and generally is integrally formed by injection molding. The locking member606is provided with a plurality of protrusions606a,606b,606c, and606d(contact surfaces) and a plurality of small protrusions606eand606f(protrusion parts).

In the present embodiment, all of the contact surfaces and the protrusion parts are integrally formed with the locking member606, but is not limited to this. The protrusions606aand606bamong the contact surfaces are provided with small protrusions606eand606f(protrusion parts), respectively. Thus, in the present embodiment, the protrusion parts are protruded from the contact surfaces. However, instead of this, the protrusion parts can also be formed differently from the contact surfaces.

A guide surface (not shown) provided inside the locking member606(the moving member) engages with a guide surface which is provided on the accessory side contact holding member601and the accessory side cover member602. Thus, the locking member606is linearly movable only in a substantially upward and downward direction.

Reference numeral608denotes a locknut (an operating member) which is rotatable. The locknut608is made of a thermoplastic resin material such as PC or ABS, and generally is integrally formed by injection molding. Furthermore, what is called, a knurled part608ais formed at the upper side of the outer periphery for improving the operability by a user, and a female screw608gis formed at the inner periphery.

Reference numeral607denotes an intermediate member which is positioned by engaging with a positioning dowel provided on each of upper surfaces of the accessory side contact holding member601and the accessory side cover member602. The intermediate member607limits the movement of the locknut608in a downward direction, and it enables the locknut608to move only in a rotational direction.

A male screw606gis formed at the outer periphery of the locking member606and is screwed into the female screw608gwhich is formed on the inner periphery surface of the locknut608. By such a configuration, the locking member606is movable in an upward and downward direction by the rotation of the locknut608. The upward and downward direction inFIG. 7is, in other words, a direction (a second direction) which intersects with a direction (a first direction) in which the accessory side contact holding member601is inserted with respect to the accessory shoe.

When the locknut608is rotatably operated and the locking member606is linearly moved in a third direction (in a downward direction which is closer to the accessory shoe), the protrusions606a,606b,606c, and606d(the contact surfaces) are in contact with the upper surfaces of the camera side engagement parts101a,101b, and101c. In the present embodiment, the protrusion606aamong the contact surfaces is in contact with the camera side engagement part101a(a first engagement part), and the protrusion606bis in contact with the camera side engagement part101b(a second engagement part). The protrusions606cand606damong the contact surfaces are in contact with the camera side engagement part101c(a third engagement part).

The protrusions606a,606b,606c, and606d(the contact surfaces) are tightly in contact with the upper surfaces of the camera side engagement parts101a,101b, and101cby further fastening the locknut608in this state.

On the other hand, the small protrusions606eand606f(the protrusion parts) fall in a groove G which is formed between the camera side engagement parts101aand101band the camera side engagement part101c(protrude into the groove). Therefore, even if the fixing strength is loosened and the accessory device attempts to slide in the second direction, the sliding in the second direction is prevented because the protrusion parts are in contact with the side surfaces of the first engagement part and the second engagement part. Thus, the protrusion parts of the accessory device of the present embodiment are in contact with the first engagement part and the second engagement part so as to prevent the accessory device from sliding in the second direction.

The small protrusion606eof the present embodiment protrudes between the camera side engagement part101a(the first engagement part) and the camera side engagement part101c(the third engagement part) by the locking member606moving in a direction of closer to the accessory shoe (a third direction). Similarly, the small protrusion606fprotrudes between the camera side engagement part101b(the second engagement part) and the camera side engagement part101c(the third engagement part).

Thus, even if the locknut608is rather loosened, it does not happen that the connection part600of the accessory device is removed from the camera side engagement plate101and the accessory device falls. Therefore, the accessory device can be stably reliably mounted.

Reference numeral609denotes a connection member. The connection member609is made of a thermoplastic resin material such as PC or ABS, and generally is integrally formed by injection molding. A positioning engagement hole for the intermediate member607and through holes that fixing screws610aand601bpass through are provided inside the connection member609. By the configuration, a position relation of the connection member609relative to the intermediate member607is determined, and the connection member609is fixed on the accessory side contact holding member601and the accessory side cover member602.

A fixing dowel which is used for the attachment to a main body of the accessory device is formed on the upper part of the connection member609, and it is connected to and fixed on the main body of the accessory device (not shown). When the connection member609is fixed on the accessory side contact holding member601and the accessory side cover member602, the movement of the locknut608in an upward direction is limited. In this case, the locknut608is movable only in a rotational direction.

A shoe mounting part (a connection part600of the accessory device) constituted as described above is mounted on the accessory shoe of the video camera main body100as shown inFIGS. 12 to 14.FIG. 12is a cross-sectional view showing a state where the connection part of the accessory device is mounted on the video camera.FIG. 13is a side view showing a sliding completed state of the connection part of the accessory device.FIG. 14is a side view showing a mounting completed state of the connection part of the accessory device. InFIGS. 13 and 14, the outline of an accessory device main body700(a video light) is shown by a dotted line.

Next, a procedure of mounting the shoe mounting part (the connection part600of the accessory device) for the accessory shoe will be described.

First, the lock member606moves up to a predetermined position in an upward direction (a direction away from the accessory shoe) by the rotational operation of the locknut608before the shoe mounting part (the connection part600of the accessory device) is mounted on the accessory shoe. The predetermined position is a position where the locknut608can not be rotated any more after the rotational operation of the locknut608.

This state is shown inFIGS. 15 and 16.FIG. 15is a perspective view of the connection member609. As shown inFIG. 15, the connection member609is provided with a first rotation stopper609a.FIG. 16Ais a plan view of the connection part of the accessory device at the predetermined position described above, andFIG. 16Bis a side view of the connection part.FIG. 16Ashows a cross-sectional plane which is cut at A-A inFIG. 16B. The first rotation stopper609aof the connection member609is in contact with a second rotation stopper608bof the locknut608. Therefore, the locknut can not rotate any more.

As shown inFIG. 13, at the predetermined position described above, the small protrusions606eand606fprovided on the locking member606are positioned over the camera side engagement plate101. Therefore, the small protrusions606eand606fdo not protrude between the camera side engagement part101a(the first engagement part) and the camera side engagement part101c(the third engagement part) and between the camera side engagement part101b(the second engagement part) and the camera side engagement part101c(the third engagement part) In other words, the small protrusions606eand606fare not in contact with a front side end surface of the camera side engagement parts101aand101b. Therefore, the connection part600of the accessory device can be inserted into the camera side engagement plate101.

Next, the positions of the accessory side contact holding member601and the accessory shoe are positioned so that a lower surface601mof the accessory side contact holding member601faces the sliding part101dprovided at the camera side engagement plate101. In this case, an accessory side connector (a front part of the accessory side contact holding member601) is positioned over the sliding space101sbetween the camera side engagement parts101aand101b. Thus, the accessory side engagement parts601aand601bare positioned at the slightly back and upper side. Hereinafter, this state is referred to as a pre-mounting preparation state.

As shown inFIG. 4, a gap between the camera side engagement parts101aand101bof the accessory shoe in the shoe width direction (a gap between the bent end parts of the camera side engagement parts101aand101b, hereinafter referred to as a “gap of the camera side engagement parts”) is represented as W1. A width of the camera side connector (the contact holding member102xand the camera side contact103) in the shoe width direction, i.e. a width between the guide wall surfaces102nand102o(hereinafter referred to as a “width of the camera side connector”) is represented as W2. Furthermore, a length from a back end of the guide wall surfaces102nand102oto a back end of the camera side engagement parts101aand101bin a frontward and backward direction (hereinafter referred to as a “sliding space length”) is represented as L1.

On the other hand, as shown inFIG. 8, a width of the accessory side connector (the contact holding part601xand the accessory side contact603) in an accessory width direction, i.e. a width between the guide wall surfaces601nand601o(hereinafter referred to as a “width of the accessory side connector”) is represented as W2′. Furthermore, a length from a front end of the accessory side engagement parts601aand601bof the accessory side contact holding member601to a front end of the accessory side connector (hereinafter referred to as a “length of the accessory side connector”) is represented as L′.

In this case, the width of the camera side connector W2and the width of the accessory side connector W2′ are set to, what is called, a fitting dimension. The gap of the camera side engagement parts W1is set to be greater than the width of the accessory side connector W2′, i.e. greater than the width of the camera side connector W2. The sliding space length L1is set to be slightly shorter than the length of the accessory side connector L1′.

Thus, in the present embodiment, the gap of the camera side engagement parts W1is set to be greater than the width of the accessory side connector W2′.

Therefore, when the shoe mounting part moves from the pre-mounting preparation state described above to a downward direction (a direction of closer to the accessory shoe), the accessory side connector passes a space between the camera side engagement parts101aand102band is inserted into the sliding space101s.

Since the length of the accessory side connector L1′ is slightly longer relative to the sliding space length L1, the front end of the accessory side connector can also be close to the camera side engagement part101c. Hereinafter, this state is referred to as a “pre-sliding state”.

In other words, the gap of the camera side engagement parts W1is set to a width where the accessory side connector having the width of the accessory side connector W2′ can pass. Therefore, the overlap of the shoe mounting part in the pre-mounting preparation state and the pre-sliding state and the accessory shoe can be enlarged.

The accessory side connector is inserted into the engagement space101tformed between the camera side engagement part101cand the camera side connector and engages with the camera side engagement part101cby sliding the shoe mounting part at the pre-sliding state in a frontward direction. The accessory side engagement parts601aand601bare inserted between the camera side engagement parts101aand101band the sliding part101dand engage with the camera side engagement parts101aand101b.

When the accessory side connector is inserted in the engagement space101tcompletely and is in contact with a part of a front wall of the camera side engagement part101c, the contact part603aof the accessory side contact603is in contact with the contact part103aof the camera side contact103.

As shown inFIG. 12, in the above state, the end part of the accessory side connector is immediately beneath the opening101e. Therefore, even if a force which tips the accessory device backward is applied for example, it will not happen that only the camera side engagement part101cdeforms.

Furthermore, since the click feel is generated by the click spring605, the user can learn that the accessory device is adequately mounted.

Subsequently, the locking member606moves in a downward direction (a direction of closer to the accessory shoe) by the rotational operation of the locknut608. Therefore, the protrusions606a,606b,606c, and606dprovided on the lower surface of the locking member606press each of the upper surfaces of the camera side engagement parts101a,101b, and101c.

With the motion described above, the small protrusions606eand606fare protruded into grooves which are formed between the camera side engagement parts101aand101band the camera side engagement part101c, and are inserted into the grooves. Therefore, even if the accessory device attempts to move in a backward direction, the movement is prevented by the small protrusions606eand606f. The state in this case is shown inFIG. 14.

In accordance with the operation described above, mounting the accessory device on the video camera main body100is completed.

Subsequently, the video camera main body100recognizes that the accessory device is mounted, and the power supply from the video camera main body100to the accessory device and the communication of signals between them start. If the accessory device needs to be removed from the video camera main body100, an operation opposite to the above operation may be performed.

As described above, in the present embodiment, the protrusions606a,606b,606c, and606dare pressed and fixed on the camera side engagement parts101aand101bby the rotational operation of the locknut608to move the locking member606in a downward direction. In addition, in the fixing state described above, the small protrusions606eand606fare protruded into the grooves which are formed between the camera side engagement parts101aand101band the camera side engagement part101cand are inserted into the grooves.

Therefore, even if the locknut608is not adequately fastened or it is somewhat loosened during use of the accessory device, the accessory device is effectively prevented from falling from the video camera main body100. As a result, the accessory device can be stably reliably mounted.

The present embodiment describes an example that two small protrusions606eand606fare inserted into grooves formed between the camera side engagement parts101aand101band the camera side engagement part101c. However, the same effect can be obtained even when the locking member606is provided with only the small protrusion606fand the small protrusion606fis inserted into the groove formed between the camera side engagement part101band the camera side engagement part101c, instead of the above example.

Unlike the construction of the conventional shoe mounting part, the locknut608that is a rotational operation part is not configured to be fastened to the camera side engagement plate101. Therefore, for example, it can be applicable even when the camera side engagement plate101is buried in the video camera main body100. Accordingly, the design freedom of the video camera main body100is dramatically improved and the video camera main body100can be miniaturized.

As described above, according to the present embodiment, an accessory device which is configured to be reliably connected to an accessory shoe with a simple configuration can be provided. Even if the rotational member of the accessory device is somewhat loosened, the accessory device does not easily fall. Therefore, according to the present embodiment, an accessory device equipped with a highly reliable connection part can be provided.

The present invention can also be applied to other image pickup apparatuses such as a single-lens reflex camera and a compact camera, which are apparatuses other than a video camera equipped with an accessory shoe.

This application claims the benefit of Japanese Patent Application No. 2007-333410, filed on Dec. 26, 2007, which is hereby incorporated by reference herein in its entirety.