Lens hood, and imaging device

A lens hood with lens covers that need not be attached to and detached from a lens unit and are easily openable and closable relative to each other. The lens hood includes a hood body attached to the front of a lens to prevent unnecessary light from being incident upon the lens, a pair of lens covers installed inside the hood body to be pivotable about an axis perpendicular to the optical axis of the lens and movable between a closed position where they will cover the lens and an opened position where they will be outside the field of view of the lens, and a cover operating mechanism that operates in conjunction with the sliding of an operator installed slidably to the hood body to pivot the lens covers in opposite directions, respectively, and to pivot the pair of lens covers between the opened and closed positions.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a lens hood attached to the front of a lens to prevent unnecessary light from being incident upon the lens, and an imaging device provided with the lens hood.

This application claims the priority of the Japanese Patent Application No. 2003-180022 filed on Jun. 24, 2003, the entirety of which is incorporated by reference herein.

2. Description of the Related Art

Conventionally, a lens hood is attached to the front of a lens in an imaging device such as a still camera, video camera or the like, as necessary, to prevent unnecessary light from being incident upon the lens during photography (cf. the Japanese Published Unexamined Patent Application No. 2000-180918). Also, a lens cover is attached to the camera device after completion of an intended series of photography to protect the lens so that the lens will not be damaged or no dust or the like will adhere to the lens surface (cf. the Japanese Published Unexamined Patent Application No. 1992-94271).

FIG. 1shows a conventional camera/video recorder (will be referred to as “video camera” hereunder), for example. The video camera is generally indicated with a reference200. As shown, the video camera200includes a body unit201, a lens unit202provided at the front of the body unit201with a field lens included in the lens unit202, facing forward, and a viewfinder203provided at the rear top of the body unit201and facing backward (in a direction opposite to that of the field lens in the lens unit202). Gripping a holder204provided at one lateral side of the body unit201, the photographer (will be referred to as “user” hereunder) peeps into the viewfinder203to see a field of view the video camera is going to capture. A lens hood205is attached to the front of the lens unit202, and further a lens cover206is removably attached to the lens hood205.

Attaching and detaching of the lens cover to the lens hood before and after making a photography with the aforementioned camera device are very troublesome. Especially, in the case of the video camera200, it is difficult for the user to detach the lens cover206from the front of the lens hood205with the eye being set to the viewfinder203while holding the holder204of the body unit201by gripping. So, to attach or detach the lens cover206, the user has to re-hold the video camera200once to direct the lens hood205toward himself or herself. Also, making sure whether the lens cover206is attached in place as well as re-holding the video camera200is very troublesome.

Also, in the case of the video camera200, the lens cover206is connected to the body unit201with a string207to prevent the detached lens cover206from being missing, as shown inFIG. 1. However, the lens cover206detached for making a photography will depend from the body unit201, which will interfere with and bother the user.

On the other hand, some of small camera devices using a small lens include a camera whose lens cover is automatically slid to a position outside the lens and a camera whose lens cover is opened to outside. In a conventional camera of a type whose lens unit is projected largely forward, like the lens unit202in the video camera200, and a conventional camera of a type whose lens hood is to be attached to the front of the camera, like the lens hood205of the video camera200, however, there is not provided any mechanism to operate (open and close) a lens cover (like the lens cover206) because such a mechanism will lead to a larger front portion of the camera. Most of the conventional camera devices of such types have a lens cover (like the lens cover206) that is to be attached and detached at each time of photography, which is very inconvenient.

OBJECT AND SUMMARY OF THE INVENTION

It is therefore an object of the present invention to overcome the above-mentioned drawbacks of the related art by providing a lens hood having lens covers easily openable from each other and closable to each other and which have not to be attached and detached at each photography.

Also the present invention has another object to provide an imaging device provided with the above-mentioned lens hood with the lens covers, according to the present invention, to assure an improved operability of the imaging device.

The above object can be attained by providing a lens hood including, according to the present invention, a hood body attached to the front of a lens to prevent unnecessary light from being incident upon the lens; a pair of lens covers installed inside the hood body to be pivotable about an axis perpendicular to the optical axis of the lens and between a closed position where they will cover the lens and an opened position where they will be outside the field of view of the lens; and a cover operating mechanism which operates in conjunction with sliding of an operator installed slidably to the hood body to pivot the lens covers in pair in opposite directions, respectively, to pivot the pair of lens covers between the opened and closed positions.

In the above lens hood according to the present invention, the pair of lens covers provided inside the hood body can easily be opened from each other and closed to each other by sliding the operator of the cover operating mechanism provided on the hood body. With the pair of lens covers being placed in the opened position, the hood body prevents unnecessary light from being incident upon the lens. The pair of lens covers set in the closed position will protect the lens by covering the latter.

Also, the above object can be attained by providing an imaging device including, according to the present invention, a device body; a lens unit provided at the front of the device body for a field lens to face forward; and a lens hood attached to the front of the lens unit, the lens hood including a hood body attached to the front of a lens to prevent unnecessary light from being incident upon the lens; a pair of lens covers installed inside the hood body to be pivotable about an axis perpendicular to the optical axis of the lens and between a closed position where they will cover the lens and an opened position where they will be outside the field of view of the lens; and a cover operating mechanism which operates in conjunction with sliding of an operator installed slidably to the hood body to pivot the lens covers in pair in opposite directions, respectively, to pivot the pair of lens covers between the opened and closed positions.

In the above imaging device, the lens hood is attached to the front of the lens unit provided at the front of the device body, and the pair of lens covers provided inside the hood body can easily be opened from each other, and closed to each other, by sliding the operator of the cover operating mechanism provided on the hood body. Therefore, it is possible to save the labor and time for attaching and detaching the lens covers before and after making a photography with the imaging device. During photography, the hood body can prevent unnecessary light from being incident upon the lens, and after making a photography, the pair of lens covers can protect the lens by covering the latter.

These objects and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments of the present invention when taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The lens hood and imaging device according to the present invention will be described in detail concerning their embodiments with reference to the accompanying drawings.

First the imaging device to which the lens hood according to the present invention is installed will be described.

Referring now toFIGS. 2 and 3, for example, there are schematically illustrated in the form of perspective views a camera/video recorder (will be referred to as “video camera” hereunder) as an embodiment of the present invention. The video camera is generally indicated with a reference1. As shown, the video camera1includes a camera body2formed to have a generally rectangular-parallelepiped shape. The camera body2has provided therein an imaging unit to take a picture of an object, a display unit to display the captured image, a sound recording unit to record sounds, a recording/playback unit to record and reproduce video and audio signals from the imaging unit and sound recording unit, respectively, control buttons and switches for controlling various operations of the video camera1.

A lens unit3having a field lens facing forward is fixed to the front of the camera body2, and a lens hood50according to the present invention, which will be described in detail later), is removably attached to the front of the lens unit3. To the rear of the camera body2, there is fixed a viewfinder4in which the photographer (will be referred to as “user” hereunder) peeps to see a field of view through the field lens. Also, to one lateral side of the camera body2, there is fixed a holder6the user will grip when holding the video camera1. The holder6has a gripping belt5provided thereon. To the side of the camera body2opposite to the side where the holder6is fixed, there is fixed a display unit7which is openable and closable, as shown inFIGS. 3 and 4. When placed in an closed position as shown inFIG. 3, the display unit7is received in a panel housing concavity8formed at the lateral side of the camera body2. When in an opened position as shown inFIG. 4, a liquid crystal display (LCD) panel9of the display unit7, provided on the main side of the latter opposite to the panel housing concavity8, will display an image captured through the field lens. Of course, this image can also be viewed through the viewfinder4.

Thus, the user can make a photography while peeping, with one of his or her eyes, into the viewfinder4at the back of the camera body2while gripping, with the single hand, the holder6provided at the one lateral side of the camera body2, or while watching the LCD panel9of the display unit7opened at the other lateral side of the camera body2.

Next, the lens hood50with lens covers according to the present invention will be illustrated and described.

As shown inFIGS. 5 and 6, the lens hood50includes a hood body51installed removably to the front of the lens unit3, an upper lens cover52and lower lens cover53in pair, installed inside the hood body51to be openable from each other and closable to each other, and a cover operating mechanism56which opens the pair of lens covers, upper and lower,52and53from each other, and also closes them to each other, by sliding an operating projection55protruding out of a sliding hole54formed in the hood body51.

The hood body51is located before the field lens of the lens unit3to prevent unnecessary light from being obliquely incident upon the field lens. It is an assembly of a front hood member57and read cover member58.

The front hood member57is shaped to have a larger diameter from the base end thereof in which a circular opening57athe field lens of the lend unit3faces toward the free end thereof. To the front side of the front hood member57, there is fixed a light-shielding plate59having a rectangular opening59aformed therein and which prevents unnecessary light from being incident upon the field lens from front. A flat, generally circular, inner wall57bdefining an opening57ais formed on the back of the front hood member57, and a flat, generally rectangular, outer wall57cdefining the lateral side of the hood body51is formed outside the inner wall57b. Both the inner and outer walls57band57care rising. Also, a projecting positioning pin60is formed at the back of the front hood member57and in each of three corners between the inner and outer walls57band57c. A screw hole60ais formed in the center of the positioning pin60.

The rear cover member58is formed to have a generally rectangular box-like shape and has a circular opening58aformed nearly in the bottom center thereof correspondingly to the opening57ain the front hood member57. A flat, generally circular, inner wall58bforming an opening58ais formed on the bottom of the rear cover member58, and a flat, generally rectangular, outer wall58cforming the lateral side of the hood body51is formed outside the inner wall58b. Both the inner and outer walls58band58care rising. Also, correspondingly to the positioning pin60on the front hood member57, a projecting positioning cap (not shown) is formed at the bottom of the read cover member58and in each of three corners between the inner and outer walls58band58c. There is formed in the bottom of the positioning cap at through-hole61through which a screw62is passed. Also, a cut defining the sliding hole54is formed in the outer wall58cof the rear cover member58.

The above front hood member57and rear cover member58are joined integrally to each other by fitting the positioning pin60into the positioning cap with the inner walls57band58bbeing made to abut each other and the outer walls57cand58cbeing made to abut each other, respectively, and driving the screw62into the screw hole60ain the positioning pin60through the through-hole61in the positioning cap. Thus, the hood body51is formed to define between the inner walls57band58band outer walls57cand58ca space in which the cover operating mechanism56, which will be described in detail later, is to be housed.

A set screw63is installed rotatably at the bottom of the hood body51as shown inFIGS. 3 and 4. By driving the set screw63into a screw hole (not shown) formed in the bottom of the lens unit3, the lens hood50can be attached to the front of the lens unit3.

As shown inFIGS. 6 to 10, the upper lens cover52is formed to have a generally semi-circular shape to cover the upper half of the field lens facing forward through the openings57aand58ain the hood body51, and has a rotating shaft64formed integrally at the base end thereof. On the other hand, the front hood member57has formed therein a pair of shaft recesses65in which the rotating shaft64is pivoted at opposite ends thereof, and has also formed thereon a pair of positioning portions66which limit the rotating shaft64from moving in the axial direction. With the rotating shaft64being engaged in the pair of shaft recesses65, the upper lens cover52is supported rotatably in a direction perpendicular to the optical axis. Also, the upper lens cover52has formed at the free end thereof a stepped overlapping portion67which overlaps the free end portion of the lower lens cover53. Also, the rotating shaft64has provided at one end thereof an arm portion68extending in a direction perpendicular to the rotating shaft64and which has an outwardly projecting boss69formed at the free end of the arm portion68.

The lower lens cover53is formed to have a generally semi-circular shape to cover the lower half of the field lens facing forward through the openings57aand58ain the hood body51, and has a rotating shaft70formed integrally at the base end thereof. On the other hand, the front hood member57has also formed therein a pair of shaft recesses71in which the rotating shaft70is pivoted at opposite ends thereof, and has formed thereon a pair of positioning portions72which limit the rotating shaft70from moving in the axial direction. With the rotating shaft70being engaged in the pair of shaft recesses71, the lower lens cover53is supported rotatably in a direction perpendicular to the optical axis. Also, the rotating shaft70has provided at one end thereof an arm portion73extending in a direction perpendicular to the rotating shaft70and which has an outwardly projecting boss74formed at the free end thereof.

Also, when the front hood member57and rear cover member58being joined integrally to each other, the rotating shafts64and70of the upper and lower lens covers52and53, respectively, will be supported at the rear sides thereof on the inner walls58bof the rear cover member58. Thus, the rotating shafts64and70of the upper and lower lens covers52and53, respectively, can positively be pivoted to provide a structure which can withstand an impact applied from the front.

As best shown inFIGS. 6,8and10, the cover operating mechanism56includes, inside the hood body51, a ring-shaped member75fitted on the inner wall57bof the front hood member57, a pair of coupling members76to provide a coupling between the ring-shaped member75and arm portions68and73of the upper and lower lens covers52and53, respectively, and a pair of helical extension springs77to force the upper and lower lens covers52and53in their pivoting directions, respectively.

The ring-shaped member75is installed to be pivotable about the optical axis while sliding on the inner wall57bof the front hood member57. Also, on the outer surface of the ring-shaped member75, there is formed a pair of bosses78projecting outwardly from opposite positions, respectively. Also, on the outer surface of the ring-shaped member75, there is formed integrally an operating projection55facing the outside through the aforementioned sliding hole54in the hood body51.

The coupling members76have formed therein boss holes79aand79b, respectively, in which there are engaged the bosses69and74formed on the arm portions68and73of the upper and lower lens covers52and53, respectively, and boss holes80aand80b, respectively, in which the bosses78on the ring-shaped member75are engaged, respectively.

The spiral extension springs77are hooked at one end thereof on the bosses69and74, respectively, formed on the arm portions68and73, respectively, of the upper and lower lens covers52and53, respectively, and at the other end thereof on hook pins81, respectively, each provided at each of the rear corners of the front hood member57, opposite to each other.

In the cover operating mechanism56, as the operating projection55facing the outside through the sliding hole54in the hood body51is slid about the optical axis, the upper and lower lens covers52and53will be pivoted about the rotating shafts64and70, respectively, in opposite directions, respectively, as shown inFIGS. 7 to 10.

Since the upper and lower lens covers52and53are pivoted by the cover operating mechanism56in the same manner except for their pivoting in opposite directions, respectively, only the operation of the cover operating mechanism56for pivoting the lower lens cover53will be described by way of example herebelow.

First, when the operating projection55is slid upward starting with the lower lens cover53being closed as shown inFIG. 11, the ring-shaped member75will be pivoted counterclockwise inFIG. 11, resulting in engagement of the boss78aon the ring-shaped member75in the boss hole80bin the coupling member76, which engagement will cause the coupling member76to pivot upward. Then, the boss74on the arm portion73is engaged into the boss hole79bin the coupling member76, so that the arm portion73will be pulled upward against the force of the spiral extension spring77. Thus, the rotating shaft70will be pivoted in a direction in which the lower lens cover53is opened.

On the other hand, when the operating projection55is slid downward starting with the lower lens cover53being opened as shown inFIG. 12, the ring-shaped member75is pivoted clockwise inFIG. 12, resulting in engagement of the boss78aon the ring-shaped member75in the boss hole80bin the coupling member76, which engagement will cause the coupling member76to be pivoted downward. Then, the boss74on the arm portion73is engaged into the boss hole79bin the coupling member76, so that the arm portion73will be pushed down against the force of the spiral extension spring77. Thus, the rotating shaft70will be pivoted in a direction in which the lower lens cover53is closed.

As schematically illustrated inFIG. 13, the spiral extension spring77forms a toggle mechanism. More specifically, depending upon at which side of a straight line S connecting the hook pin81on which the spiral extension spring77is hooked at the other end thereof and the center of rotation of the rotating shaft70of the lower lens cover53the boss74on the arm portion73on which the spiral extension spring77is hooked at one end thereof is positioned, the direction of the force applied to the free end of the arm portion73will be switched between a direction in which the lens cover is pivoted toward the closed position and a direction in which the lens cover is pivoted toward the opened position.

Then in the cover operating mechanism56, the range of an angle in which each of the upper and lower lens covers52and53is pivotable is set to 100 deg. and the directions in which the arm portions68and73of the rotating shafts64and70, respectively, are extended, respectively, are set for the above-mentioned straight line S to be parallel with the optical axis.

Also in the cover operating mechanism56, the boss holes80aand80bin the coupling members76, respectively, are elongated ones different in length from each other. More particularly, the boss hole80ain the coupling member76coupled to the upper lens cover52is shaped to be about 1.5 mm longer than the boss hole80bin the coupling member76coupled to the lower lens cover53. Thus, the boss78in the ring-shaped member75will first touch the boss hole80bin the coupling member76coupled to the lower lens cover53.

Therefore, when closing the lens covers52and53, the lower lens cover53will be closed by the cover operating mechanism56more early than the upper lens cover52so that the stepped overlapping portion67of the upper lens cover52can positively be made to overlap the free end of the lower lens cover53. It should be noted that the upper and lower lens covers52and53will be opened simultaneously by the cover operating mechanism56.

In the video camera1provided with the aforementioned lens hood50, the upper and lower lens covers52and53housed inside the hood body51can easily be opened and closed by sliding the operating projection55of the cover operating mechanism56provided on the hood body51.

With the lens covers52and53being closed as shown inFIGS. 7 and 14, they can positively protect the field lens3aof the lens unit3against any damage to the field lens3aand adhesion of dust to the field lens3aby covering the field lens3aof the lens unit3.

On the other hand, when the upper and lower lens covers52and53are opened from each other as shown inFIGS. 9 and 15, the hood body51will be moved to outside the field of view of the field lens3aand hence can appropriately prevent unnecessary light from being incident upon the field lens3a.

As having been described above, in the video camera1provided with the aforementioned lens hood50, the lens covers52and53will not have to be attached or detached before or after each use of the video camera1, the lens covers52and53will not interfere with the preparative operation of the video camera1for a photography, and the lens covers52and53can easily be opened and closed, which will further assure an improved operability of the video camera1.

Especially, in case the video camera1is provided with the lens hood50, the user can easily open and close the lens covers52and53by sliding the operating projection55located at the other lateral side of the lens hood50even while gripping the holder6of the device body2and peeping into the viewfinder4, and can easily check whether the lens covers52and53are opened or closed. Therefore, the user quickly start an intended photography with the video camera1without having to re-holding the latter once.

Also, since the lens hood50can have the lens covers52and53thereof opened and closed inside the hood body51, so it will not esthetically be spoiled and can be designed compact and lightweight.

Also, in the lens hood50, since the lens covers52and53to be opened from each other are forced by the toggle mechanism formed by the spiral extension spring77in a direction in which they are pivoted toward the opened position while the lens covers52and53to be closed are forced by the toggle mechanism in a direction in which they are pivoted toward the closed position, so it is possible to prevent the lens covers52and53from being inadvertently opened or closed in the course of a photography or while the video camera1is being carried.

Also, the lens hood50can easily be attached to and detached from the video camera1. For example, a conversion lens or the like installed to the lens unit3can be detected along with the lens covers52and53from the lens unit3. Also, a filter or the like can be installed to the lens unit3with the lens hood50being left installed to the video camera1.

Note that the present invention is not limited to the aforementioned lens hood50provided with the cover operating mechanism56which pivots the aforementioned upper and lower lens covers52and53between the opened and closed positions as the user slides the operating projection55about the optical axis of the field lens3a(or in a direction perpendicular to the optical axis).

For example, the lens hood50may be modified to be a lens hood100shown inFIG. 16. The lens hood100includes the hood body51having a sliding hole101formed therein, and a cover operating mechanism103adapted to pivot the aforementioned lower and upper lens covers52and53between the opened and closed positions by sliding an operating projection102provided in the cover operating mechanism103to face the outside through the sliding hole101in the direction of the optical axis of the field lens3a.

More specifically, the cover operating mechanism103includes a sliding member104having the operating projection102provided thereon, and a pair of coupling members105to provide a coupling between the sliding member104and the upper and lower lens covers52and53, as shown inFIG. 17.

The sliding member104has a pair of coupling member106provided at one sliding-directional side thereof and projected in parallel to each other. Each of the coupling members106has formed at the free end thereof a boss107projected outwardly.

Each of the coupling members105in pair has formed therein a coupling hole109in which a coupling pin108projected outwardly from one lateral side of each of the upper and lower lens covers52and53, and a boss hole110in which a corresponding one of the bosses107formed on the sliding member104is engaged.

Therefore, in the cover operating mechanism103constructed as above, as the coupling members105in pair are pivoted in opposite directions, respectively, about the bosses107, respectively, in conjunction with sliding of the operating projection102in the optical-axial direction, the aforementioned upper and lower lens covers52and53can appropriately be pivoted in opposite directions, respectively, between the opened and closed positions.

Also, although the upper and lower lens covers52and53in the closed position are opened outwardly as having been mentioned above, the lens hood may be designed so that the lens covers52and53in the closed position are opened inwardly.

Note that according to the present invention, the lens hood may be adapted so that a single circular lens cover housed in the hood body can be pivoted by the cover operating mechanism between a closed position where it will cover the lens and an opened position where it will be outside the field of view of the lens.

Also note that the present invention is not limited to the aforementioned video camera1but is widely applicable to imaging devices such as a still camera, to which a lens hood can be attached.

In the foregoing, the present invention has been described in detail concerning certain preferred embodiments thereof as examples with reference to the accompanying drawings. However, it should be understood by those ordinarily skilled in the art that the present invention is not limited to the embodiments but can be modified in various manners, constructed alternatively or embodied in various other forms without departing from the scope and spirit thereof as set forth and defined in the appended claims.