JP2003167181A - Camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem that if a lens barrel unit is directly fixed on a camera body, a high load is applied on the lens barrel unit (inside) when external force is applied on the lens barrel unit. <P>SOLUTION: The camera is provided with the camera body and the lens barrel unit for storing an optical system for forming an object luminous flux on an image pickup surface in the camera body, and the lens barrel unit 21 is connected to the camera body 1 through an elastic member 2. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for holding a lens barrel unit in a camera such as a silver salt camera, a video camera, a digital camera or the like.

[0002]

2. Description of the Related Art A lens barrel unit is fixed by screws while being positioned with respect to a main chassis (camera body). The barrel unit is composed of a plurality of barrels, and when receiving power from a drive source provided in the camera body, the barrel barrel unit is extended or retracted in the optical axis direction by a cam engagement action of the barrels. Further, the lens barrel unit accommodates an optical system for forming a subject light flux on the image pickup surface in the camera body, and the focal length can be changed by retracting and retracting the lens barrel unit.

[0003]

However, if the lens barrel unit is directly fixed to the main chassis with screws as in the above-mentioned prior art, when a force from the outside is applied to the lens barrel unit in the extended state, the mirror unit is A high load is applied to the inside of the barrel unit, for example, the engaging portion of each barrel of the plurality of barrels forming the barrel unit.

Therefore, an object of the present invention is to reduce the load on the lens barrel unit (inside) when an external force is applied to the lens barrel unit. Another object of the present invention is to realize a camera structure that is excellent in drip-proof and dust-proof by keeping the clearance between the lens barrel unit and the camera body uniform.

[0005]

The present invention has a camera body and a lens barrel unit for housing an optical system for forming a subject light flux on an image pickup surface in the camera body. , And is connected to the camera body via an elastic member.

By thus coupling the lens barrel unit to the camera body via the elastic member, even if an external force is applied to the lens barrel unit, the elastic member can be elastically deformed to absorb the external force. The load on the lens barrel unit can be reduced.

Here, the lens barrel unit and the exterior member constituting the exterior of the camera body may be radially fitted to each other to suppress the movement of the lens barrel unit in the direction orthogonal to the optical axis. When the lens barrel unit is coupled to the camera body via the elastic member, the elastic member is elastically deformed by an external force or the like and the lens barrel unit moves in the direction orthogonal to the optical axis. It is possible to prevent the movement of the lens barrel unit in the plane orthogonal to the optical axis by fitting the two.

The diameter fitting portions of the lens barrel unit and the exterior member are prevented from being disengaged from each other even if the lens barrel unit is displaced in the optical axis direction by the deformation of the elastic member. You may comprise. With this configuration, the clearance between the lens barrel unit and the exterior member can be kept constant.

Further, the diameter fitting portion may be composed of a lens barrel unit and a ring member forming a part of the exterior member.
Further, the ring member may be made of an elastic material having an elastic coefficient higher than that of the material forming the elastic member.

By thus forming the ring member with an elastic material, the ring member and the lens barrel unit can be brought into close contact with each other, and water droplets and dust are prevented from entering the camera body from the diameter fitting portion of the ring member and the lens barrel unit. The lens barrel unit can be positioned in the plane orthogonal to the optical axis by preventing the lens barrel unit from entering and by making the elastic coefficient of the ring member higher than that of the elastic member.

[0011]

1 is an exploded perspective view of a lens barrel unit in a camera which is an embodiment of the present invention.

Reference numeral 21 denotes a CC which is a base of the lens barrel unit.
It is a D holder. Reference numeral 22 denotes an optical LPF and an infrared cut filter (hereinafter referred to as LPF), which is incorporated in the CCD holder 21. Reference numeral 23 denotes a CCD rubber, which is incorporated in the CCD holder 21 and seals between the LPF 22 and the CCD 8.

Reference numeral 24 is a CCD mounting plate to which the CCD 8 is adhered and incorporated in the CCD holder 21. Reference numeral 25 denotes a third group lens barrel having a focusing function, in which a lens group is arranged on the inner circumference, and a third group cap is provided via a guide bar 26 and a sub guide bar (not shown) formed on the third group cap 27. It is held at 27. The third group lens barrel 25 can be moved in the optical axis direction by the guide bar 26 and the guide bars of the third group cap 27, and focusing can be performed by the movement in the optical axis direction.

Reference numeral 40 is a focus motor unit, and a known stepping motor is incorporated in this unit. A lead screw 40a constitutes a part of the focus motor unit and is engaged with a nut (not shown) incorporated in the third group lens barrel 25. The rotation of the stepping motor rotates the lead screw 40a, and the engagement between the lead screw 40a and the nut moves the third lens barrel 25 forward and backward in the optical axis direction.

The third group lens barrel 25 is provided with a rib 25a (not shown) for blocking the detection light of a known photo interrupter. The position control of the third group lens barrel 25 is performed by counting the pulses output from the photo interrupter. Specifically, the position control of the third group lens barrel 25 is performed based on the number of pulses counted when the third group lens barrel 25 moves in the optical axis direction from the predetermined position where the pulse number is reset to zero.

Reference numeral 28 is a coil spring that pushes the third group lens barrel 25 in the optical axis direction. Reference numeral 27 denotes a third group cap for holding the tip of the guide bar 26 and the tip of the lead screw 40a, which is incorporated in the CCD holder 21.

Reference numeral 29 denotes a second group lens barrel having a zoom function, in which a lens group is arranged on the inner circumference. The second-group barrel is incorporated in the diaphragm / shutter 30 and moves integrally with the diaphragm / shutter 30. A shutter 30 also serves as a diaphragm, and three follower pins 3 are provided at an outer circumference of this shutter at intervals of 120 degrees.
0a is formed.

Reference numeral 31 denotes a first-group lens barrel having a zoom function, in which a lens group is arranged on the inner circumference and three follower pins 31a are formed on the outer circumference at intervals of 120 degrees. Here, the zooming operation of the camera in the present embodiment is performed by the first group lens barrels 31 and 2
This is performed by changing the positional relationship of the group barrel 29 in the optical axis direction.

Reference numeral 32 denotes a straight-moving guide cylinder, which has straight-moving grooves 32b and 32c extending in the optical axis direction, and moves integrally with a moving cam cylinder 33 described later. The follower pin 31a of the first-group lens barrel 31 penetrates the rectilinear groove 32b, and the follower pin 30a of the diaphragm / shutter 30 penetrates the rectilinear groove 32c. As a result, the straight-ahead guide cylinder 32 restricts the rotation of the first-group lens barrel 31 and the shutter 30 that also serves as the diaphragm around the optical axis, and linearly moves only in the optical axis direction.

Three keys 32a are formed on the outer circumference of the straight guide cylinder 32 at intervals of 120 degrees. Key 32a
Engages with a straight-movement key groove provided on the inner circumference of the fixed barrel 34, so that the straight-movement guide barrel 32 can be moved only in the optical axis direction.

Numeral 33 is a moving cam barrel, which has a first-group cam groove and a second-group cam groove formed on its inner circumference. The follower pin 31a of the first-group lens barrel 31 penetrating the rectilinear groove 32b of the rectilinear guide cylinder 32 is engaged with the first-group cam groove, and the second-group cam groove also serves as a diaphragm penetrating the rectilinear groove 32c of the rectilinear guide cylinder 32. The follower pin 30a of the shutter 30 is engaged.

Three follower pins 33a are formed on the outer circumference of the moving cam barrel 33 at intervals of 120 degrees.
Three drive pins 33b are formed at intervals of 120 degrees.

The drive pin 33b penetrates a hole (not shown) formed in the fixed cylinder 34 and engages with a groove (not shown) formed in the inner peripheral surface of the drive cylinder 35.

Reference numeral 34 is a fixed cylinder, and a cam groove (not shown) which engages with the follower pin 33a of the movable cam cylinder 33 is formed on the inner periphery of the fixed cylinder.
Is formed, and is fixed to the CCD holder 21 while being positioned.

Reference numeral 35 denotes a drive cylinder, which is arranged on the outer periphery of the fixed cylinder 34. A gear portion that meshes with the output gear of the final stage of the zoom motor unit 20 is formed on the outer periphery of the drive barrel 35, and a cam that engages with a follower portion 36a of an LS drive lever 36 described later is formed. . The drive cylinder 35 is the zoom motor 20 of the zoom motor unit 20.
By receiving the rotational force of a, it becomes possible to rotate around the optical axis.

Reference numeral 36 is an LS drive lever, which is a drive cylinder 35.
Has a follower portion 36a that engages with the cam and a groove portion 36b that engages with the input shaft 39a of the potentiometer 39. 37 is an LS guide bar, which is an LS drive lever 36
To guide the LS drive lever 36 in the optical axis direction. The LS guide bar 37 is held by the CCD holder 21 and the fixed barrel 34.

In the configuration of the LS drive lever 36 described above, when the drive barrel 35 rotates around the optical axis, the LS drive lever 36 can move in the optical axis direction via the follower portion 36a and the LS guide bar 37. . With the movement of the LS drive lever 36 in the optical axis direction, the input shaft 39a of the potentiometer 39 moves in the optical axis direction, and the output value of the potentiometer 39 depends on the position of the LS drive lever 36 in the optical axis direction. Changes. That is, the rotation angle of the drive cylinder 35 can be detected based on the output value of the potentiometer 3.

Here, the rotation angle of the drive barrel 35 is the first group lens barrel 3
1 and the shutter / combined shutter 30 in the optical axis direction correspond to each other. Therefore, by detecting the output value of the potentiometer 39, whether the first group lens barrel 31 and the combined shutter 30 are in the retracted position, It is possible to determine whether it is in the zoom wide position, the zoom tele position, the position in the feed-in / retract region, or the position in the photographing region.

Reference numeral 38 denotes an LS spring, which is a tension coil spring hung between the LS drive lever 36 and the fixed barrel 34 in order to bias the play between the follower portion 36a of the LS drive lever 36 and the cam of the drive barrel 35. .

Next, the zoom operation of the camera of this embodiment will be described.

DC motor 2 of zoom motor unit 20
When 0a is rotationally driven, this rotational force is transmitted to the drive cylinder 35 via a gear train composed of spur gears (not shown), and the drive cylinder 3 is driven.
5 rotates around the optical axis.

Along with this, the drive pin 33b is used to drive the drive cylinder 35.
The movable cam cylinder 33 engaged with the shaft rotates around the optical axis.
Further, since the follower pin 33a is engaged with the cam groove formed on the inner circumference of the fixed barrel 34, the moving cam barrel 33 also moves in the optical axis direction along the locus of the cam groove.

When the moving cam cylinder 33 moves in the optical axis direction while rotating around the optical axis, the linear guide cylinder 32 integrally attached to the movable cam cylinder 33 also moves, but the linear guide cylinder 32 has the key 32a. Does not rotate around the optical axis because it is engaged with the straight groove formed on the inner circumference of the fixed barrel 34.

When the movable cam barrel 33 rotates in the optical axis direction while rotating around the optical axis, the follower pin 31a of the first-group barrel 31 is guided by the first-group cam groove of the movable cam barrel 33 in the optical axis direction. While moving, the follower pin 30a of the aperture / shutter 30 is guided by the second cam groove and moves in the optical axis direction. Here, the follower pin 31 a and the follower pin 30 a are respectively arranged in the straight-moving groove 32 of the straight-moving guide cylinder 32.
Since rotation around the optical axis is restricted by b and 32c, it is possible to move only in the optical axis direction.

In the camera of this embodiment, the first-group barrel 3
The distance from the image pickup surface of the lens group in 1 and the lens group in the shutter / shutter 30 is the driving amount of the moving cam barrel 33 by the cam groove provided on the inner periphery of the fixed barrel 34, and the moving cam barrel 3
It is determined based on the sum of the drive amounts of the first-group barrel 31 and the aperture / shutter 30 by the first-group cam and the second-group cam provided on the inner circumference of the third lens group 3. The above-described extension / retraction operation (zoom operation) of the lens barrel unit can be performed by switching the rotation direction of the DC motor 20a in the zoom motor unit 20.

Next, the structure when the above-mentioned lens barrel unit is incorporated in the camera body will be described with reference to FIGS. Here, FIG. 2 and FIG. 3 are longitudinal sectional views in the optical axis direction of the camera of this embodiment. 2 is a sectional view when the lens barrel unit is in the retracted position, and FIG. 3 is a sectional view when the lens barrel unit is in the extended position.

Reference numeral 1 denotes a main chassis, which is an internal structure inside the camera body to which the above-mentioned lens barrel unit is attached. In addition to the lens barrel unit, a battery case (not shown), various substrates, covers, etc. are attached to the main chassis 1. Reference numeral 2 is an elastically deformable damper rubber (elastic member described in the claims of the present application), which is arranged between the CCD holder 21 and the main chassis 1. The damper rubber 2
Alternatively, an elastically deformable member such as a spring may be used.

Reference numeral 3 is a step screw, which is screwed to the CCD holder 21 with the main chassis 1 and the damper rubber 2 sandwiched therebetween. The step screws 3 are arranged at three locations on the outer periphery of the opening 1c of the main chassis 1.

Here, the positioning of the CCD holder 21 and the main chassis 1 is performed by fitting the boss portion 21a of the CCD holder 21 into the hole portion 1a of the main chassis 1.

The boss portion 21a is fitted in the hole portion 1a with some play. In addition, step screw 3
Also, it is fitted into the hole 1b of the main chassis 1 with some play.

Since the damper rubber 2 is sandwiched between the main chassis 1 and the CCD holder 21, the lens barrel unit is screwed to the main chassis 1 with the step screw 3 (the front cover 4 and the decorative ring 5 are incorporated. 2), the lens barrel unit can be displaced in the arrow A direction (around the optical axis) and the arrow B direction (the optical axis direction) in FIG. In other words, the lens barrel unit is restricted from being displaced in the arrow C direction (optical axis direction) by tightening the stepped screw 3.

When the lens barrel unit receives a force in the arrow B direction, the lens barrel unit is displaced in the arrow B direction by elastic deformation (compression) of the damper rubber 2. Here, the CCD holder 21
Since the seat portion 21b is formed on the seat 21, the displacement amount of the lens barrel unit in the direction of the arrow B is until the seat portion 21b comes into contact with the main chassis 1. Therefore, by appropriately changing the position where the seat portion 21b is provided, the amount of displacement of the lens barrel unit in the direction of arrow B can be changed.

As described above, when an external impact is applied to the lens barrel unit, the damper rubber 2 is elastically deformed so that the lens barrel unit can be displaced in the arrow B direction.
It is possible to disperse external impacts and prevent a high load from being applied to the lens barrel unit (inside).

On the other hand, the lengths of the fixed barrel 34 and the decorative ring 5 in the optical axis direction are appropriately set according to the amount of displacement of the lens barrel unit in the arrow B direction. That is, the lengths of the fixed barrel 34 and the decorative ring 5 in the optical axis direction are set so that the engagement between the decorative ring 5 and the fixed barrel 34 is not disengaged even when the lens barrel unit is displaced in the direction of the arrow B. .

4 is a front cover, which is the main chassis 1
It is fixed in the state where it is positioned. A decorative ring 5 (a ring member described in the claims of the present application) is fixed to the front cover 4 while being positioned. The decorative ring 5 may be made of either a non-elastic material or an elastic material such as rubber. When an elastic material is used as the material of the decorative ring 5, it is preferable to use a material having a higher elastic coefficient than the material of the damper rubber 2.

The inner diameter of the rear end portion 5a of the decorative ring 5 (the diameter fitting portion described in the claims of the present application) is determined by the front end portion 34a of the fixed cylinder 34 (the diameter fitting portion of the claims of the present application).
It is formed so as to substantially match the outer diameter dimension of. Therefore, by incorporating the decorative ring 5 into the camera body, the lens barrel unit is positioned in the direction orthogonal to the optical axis, and the lens barrel unit can be displaced only in the optical axis direction.

Here, even when an elastic material is used as the material of the decorative ring 5, by using a material that is stiffer (having a higher elastic coefficient) than the material of the damper rubber 2 as the material of the decorative ring 5, the lens barrel The unit can be positioned in the plane orthogonal to the optical axis.

The inner diameter of the decorative ring 5 is set larger than the outer diameter of the moving cam ring 33. Therefore, when the moving cam ring 33 is extended, it does not interfere with the decorative ring 5.

As described above, even when the lens barrel unit is displaced by receiving an external force, the lens barrel unit (fixed cylinder 34) is prevented from being disengaged from the engagement with the decorative ring 5, so that the decorative ring 5 and the lens barrel unit can be prevented. Clearance (distance between the outer peripheral portion 34a of the fixed cylinder 34 and the inner peripheral portion 5a of the decorative ring 5)
Can be kept uniform, and this clearance can be kept to a minimum by making the outer diameter dimension at the front end portion 34a of the fixed cylinder 34 and the inner diameter dimension at the rear end portion 5a of the decorative ring 5 substantially match. .

In the above-mentioned structure, the head 3 of the step screw 3
By disposing an elastic member between a and the main chassis 1 and configuring the decorative ring 5 with an elastic material, a state in which all the connecting portions between the lens barrel unit and the camera body are coupled via the elastic member Therefore, it is possible to absorb the vibration when the lens barrel unit operates (extend and retract), reduce the propagation due to this vibration, and prevent noise from entering the microphone or the like.

Further, even if an external force is applied to the lens barrel unit in the extended state from any direction, this elastic force can be absorbed by elastic deformation of the lens barrel unit, and a high load is applied to the lens barrel unit (inside). This can be prevented.

Further, by forming the decorative ring 5 from an elastic material, the rear end portion 5a of the decorative ring 5 can be brought into close contact with the front end portion 34a of the fixed barrel 34, so that it is formed on the inner peripheral side of the decorative ring 5. It is possible to completely prevent water droplets, dust, etc. from entering the camera body through the formed gap 5 ′, and it is possible to improve the reliability of the product.

[0053]

According to the present invention, by disposing the elastic member between the lens barrel unit and the camera body, even if an external force is applied to the lens barrel unit, the elastic member elastically deforms to absorb this external force. Therefore, the load applied to the lens barrel unit can be reduced.

When the lens barrel unit is connected to the camera body via the elastic member, the elastic member is elastically deformed by an external force or the like, and the lens barrel unit moves in the direction orthogonal to the optical axis. It is possible to prevent the movement of the lens barrel unit in the plane orthogonal to the optical axis by radially fitting the barrel unit and the exterior member.

In addition, the diameter fitting portions of the lens barrel unit and the exterior member should not be disengaged from each other even if the lens barrel unit is displaced in the optical axis direction by the deformation of the elastic member. With this configuration, the clearance between the lens barrel unit and the exterior member can be kept constant.

Further, the diameter fitting portion is constituted by the lens barrel unit and a ring member forming a part of the exterior member, and the ring member is made of an elastic material to bring the ring member and the lens barrel unit into close contact with each other. It is possible to prevent water droplets and dust from entering the camera body from the diameter fitting portion of the ring member and the lens barrel unit, and to make the elastic coefficient of the ring member higher than that of the elastic member. Thus, the lens barrel unit can be positioned in the plane orthogonal to the optical axis.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a lens barrel unit.

FIG. 2 is a partial sectional view of the camera in a sunk state.

FIG. 3 is a partial cross-sectional view of the camera in a extended state.

[Explanation of symbols]

1 ... Main chassis 2 ... Damper rubber 3 ... Screw 4 ... Front cover 5 ... Makeup ring 21 ... CCD holder 34 ... Fixed tube

Claims (5)

[Claims] 1. A camera body, and a lens barrel unit for accommodating an optical system for forming a light flux of a subject on an image pickup surface in the camera body, wherein the lens barrel unit includes an elastic member for the camera. A camera characterized by being connected to the main body. 2. The lens barrel unit according to claim 1, wherein movement of the lens barrel unit in a direction orthogonal to the optical axis is suppressed by radial fitting with an exterior member forming an exterior of the camera body. camera. 3. The diameter fitting portion of the lens barrel unit and the outer casing member fits the lens barrel unit and the outer casing member even if the lens barrel unit is displaced in the optical axis direction due to deformation of the elastic member. The camera according to claim 2, wherein the camera is configured so as not to be out of alignment. 4. The camera according to claim 3, wherein the diameter fitting portion includes the barrel unit and a ring member that forms a part of the exterior member. 5. The camera according to claim 4, wherein the ring member is formed of an elastic material having an elastic coefficient higher than that of a material forming the elastic member.