JP3008741B2 - Camera barrel structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera lens barrel structure.

[0002]

2. Description of the Related Art FIG. 3 is a partial cross-sectional view showing a lens barrel structure of a conventional camera. Reference numeral 101 denotes a driving ring, and 102 denotes a fixed cylinder in which the driving ring 101 is fitted on an outer peripheral surface and fixed to a camera body. , 103 is a differential cylinder which is located on the inner peripheral portion of the fixed cylinder 102 and is fed while rotating with respect to the fixed cylinder. 104 is a key groove which is fed integrally with the differential cylinder 103 and provided in the fixed cylinder 102. A rectilinear guide 105 in which the rotation direction is regulated by engaging an engagement projection (not shown)
Is a drive pin which is screw-coupled to the differential barrel 103, engages with a cam groove 102a provided on the fixed barrel 102, and further engages a distal end thereof with a linear groove 101a of the drive ring 101.

Each lens group holding member (not shown) includes a linear groove (not shown) of the linear guide 104 and the differential cylinder 1.
The position of the driving pin 101 is regulated by a cam groove (not shown) formed on the inner peripheral portion of the driving pin 103.
5 is extended along the cam groove 102a of the fixed cylinder 102, and as a result, the differential cylinder 103 is extended while rotating.

At this time, the rectilinear guide 104 is fixed to the drive pin 105, and one end thereof is fed out together with the differential cylinder 103 by the action of an L-shaped stopper member 106. Are engaged with the linear guide keyway of the fixed cylinder 102, so that they are fed out integrally with the differential cylinder 103 without rotating. Due to the relative rotation of the differential barrel 103 and the linear guide 104, each lens group holding member is further extended in the differential barrel, and so-called differential zoom is performed.

[0005] Fig. 4 shows that the straight guide 104 is provided with a flange 104a, and the straight guide guide retaining member 106 is screwed into a screw hole 104c provided in the flange 104a.
7, and is fixed.

FIG. 5 is a partial cross-sectional view showing another conventional example.
FIG. 6 is an exploded perspective view thereof.

[0007] In FIGS. 5 and 6 in which the same parts as those in FIG.
Reference numeral 04 denotes an inner peripheral portion of the one-lens group holding member 107, and the key groove 107a of the one-lens group holding member 107 and the projection 104a of the rectilinear guide 104 are key-coupled, so that the rotation of the one-lens group holding member 107 is restricted. Is being done.

Similarly, two lens group holding members 111 and 3
The lens group holding member 112 also has the respective key groove portions 111.
a, 112a are protrusions 104a of the straight guide 104;
The rotation is regulated by key combination.

Reference numeral 108 denotes a decorative plate attached to the front end of the one-lens group holding member 107, 109 denotes a holder for the one-lens group 110, and 113, 114, and 115 denote one-lens group holding members 10.
7, 2 lens group holding member 111, 3 lens group holding member 1
12 and the projections 113, 11
Reference numerals 4 and 115 are engaged with concave portions formed on the inner surface of the differential cylinder 103.

[0010]

However, in the above conventional example, (1) a retaining member 106 fixed to the drive pin 105;
However, there is a problem that the number of parts and the number of assembling steps increase.

(2) In particular, in the conventional examples shown in FIGS. 5 and 6, (a) the one lens group holding member 107 has a notched key groove 107a on the inner peripheral surface thereof, and the two and three lens group holding members 11
Key grooves 111a, 11
Since 2a is required, the space cannot be used effectively.

(B) The straight guide 104 does not have a leading end connected in a ring shape. Therefore, in order to restrict the rotation of each lens group at the front end, it is necessary to increase the thickness of the root portion 104b, which is disadvantageous in terms of space. In addition, there is a problem that it is difficult to obtain the dimensional accuracy of the component because the tip portion is not connected in a ring shape.

(3) Cam groove 1 formed in fixed cylinder 102
In mold 02a, a so-called mold split portion is formed in the middle of the cam groove to avoid undercut due to the mold structure, and a step occurs at that portion, so that the optical position at that position cannot be guaranteed. Then, it is necessary to post-process the cam groove, and there has been a problem that parts are expensive.

(4) In order to solve the above-mentioned problem (2), as shown in FIG. 7, the linear guide 104 is connected to the first lens group holding member 107, the second lens group holding member 111 and the third lens group holding member 112. Pins 116, 1 located on the outer periphery
17 and 118 are inserted into the linear groove 10 of the linear guide 104.
4a and the cam groove portions 103a, 103b of the differential cylinder 103,
In the case of engaging with the lever 103c and defining its position, the following problem occurs.

When the tip of the one lens group holding member 107 hits a desk or the like while carrying the camera, the impact force is received by the pin 116 and the cam groove 103a. At this time, a portion for receiving the impact force and the pin 116 are screwed to the one lens group holding member 107.
7a, since the thickness of the straight guide 104 is separated, a moment force is applied to the screw portion in addition to the impact force,
There is a problem in strength when coupling only the thick portion of the one lens group holding member 107.

Further, in order to solve this problem, a nut is arranged on the inner periphery of the one lens group holding member 107,
If the structure is such that the one lens group holding member 107 is interposed between the nut 16 and a nut (not shown), the number of parts increases, the cost increases, and the number of cutouts for escaping the nut is two.
Since it is necessary for the lens group holding member 111, the above (2)
As described above, there is a problem in space efficiency.

An object of the present invention is to provide a lens barrel structure for a camera that solves the above-mentioned problems.

[0018]

According to the first aspect of the present invention, a fixed barrel that holds a photographic lens optical system and is fixed to a camera body, and is rotatably held on the inner peripheral surface of the fixed barrel. In addition, a differential cylinder whose optical axis direction position is defined by its rotation phase, and an optical axis direction position located on the inner peripheral side of the differential cylinder and defined corresponding to the position of the differential cylinder A linear guide whose rotation phase is defined by the fixed cylinder, a drive pin located on the outer peripheral portion of the fixed cylinder and fixed to the differential cylinder, and a drive ring for applying a rotational force to the drive pin. A projection that engages with a circumferential groove provided on the rectilinear guide to rotatably hold the rectilinear guide with respect to the differential cylinder and that prevents a protrusion from coming off. Cost reduction and assembly Reduction of man-hours is possible.

According to the second aspect of the present invention, the fixed barrel that holds the photographic lens optical system and is fixed to the camera body, is rotatably held on the inner peripheral surface of the fixed barrel, and has a rotation phase that is A differential tube whose position in the optical axis direction is defined; and an optical axis direction position which is located on the inner peripheral side of the differential tube and is defined corresponding to the position of the differential tube, and the rotational phase is fixed. A linear guide defined by a cylinder, and at least two optical elements whose rotation is regulated by the linear guide and whose optical position is defined by a cam groove formed in the differential cylinder.
In the camera having the two lens group holding members, the straight guide has a straight groove for regulating the rotation of the lens group holding member, and a key part for regulating the rotation of the straight guide itself is formed in phase with the straight groove. By doing so, it is possible to improve space efficiency, improve component accuracy, and improve productivity.

According to the third aspect of the present invention, the fixed barrel which holds the photographic lens optical system and is fixed to the camera body, is rotatably held on the inner peripheral surface of the fixed barrel, and has a rotational phase. A differential tube whose position in the optical axis direction is defined; and an optical axis direction position which is located on the inner peripheral side of the differential tube and is defined corresponding to the position of the differential tube, and the rotational phase is fixed. A camera having a linear guide defined by a cylinder, a drive pin positioned on an outer peripheral portion of the fixed cylinder and fixed to the differential cylinder, and a drive ring for applying a rotational force to the drive pin; The fixed cylinder and the differential cylinder are helicoid-coupled, and the fixed cylinder has a groove through which the drive pin penetrates, and the groove is formed so as not to be fitted with the drive pin, so that the impact resistance is improved. A camera that is excellent in quality

According to the fourth aspect of the present invention, the fixed barrel which holds the photographic lens optical system and is fixed to the camera body, is rotatably held on the inner peripheral surface of the fixed barrel, and has a rotational phase. A differential tube whose position in the optical axis direction is defined; and an optical axis direction position which is located on the inner peripheral side of the differential tube and is defined corresponding to the position of the differential tube, and the rotational phase is fixed. An optical position is defined by engaging a pin formed on an outer peripheral portion of a linear guide defined by a cylinder, a linear groove formed in the linear guide, and a cam groove formed in the differential cylinder. In the camera having at least two lens group holding members, the pin is formed integrally with the lens group holding member at least up to a portion that engages with the linear guide, so that the pin has excellent impact resistance. ,
A camera that is advantageous in terms of space can be realized.

[0022]

1 is a sectional view of an essential part showing an embodiment of the present invention, and FIG. 2 is an exploded perspective view thereof.

In FIG. 1 and FIG. 2, reference numeral 1 denotes a driving ring which rotates by being supplied with a force from a driving source (not shown) through a known power transmission means (not shown).
The rectilinear grooves 1a, 1b, 1c provided in the above-mentioned portions engage with the driving pins 5 to be described later to apply a rotational force. Reference numeral 2 denotes a fixed barrel fixed to a camera body (not shown). The drive ring 1 is rotatably fitted and held on the outer peripheral surface of the fixed barrel 2, and three female helicoids 2a are formed.

Reference numeral 3 denotes a differential cylinder fitted inside the fixed cylinder 2. This differential cylinder 3 has female helicoids 2 corresponding to three male helicoids 3a formed on the outer surface of the end.
is helicoid-bonded to a. The fixed cylinder 2 has a groove 2b through which the drive pin 5 penetrates, and the drive pin 5 penetrates the groove, and the tip of the drive pin 5 fits into the linear groove 1a of the drive ring 1.

Reference numeral 4 denotes a linear guide which is rotatably fitted and held on the inner peripheral portion of the differential cylinder 3. Reference numeral 5 denotes a drive pin which is threaded into the screw hole 3b of the differential cylinder 3 through the straight groove 1a of the drive ring 1 and the groove 2b of the fixed cylinder 2, and a screw tip of the drive pin 5 which has passed through the screw hole 3b. Projection 5a formed on the part
Are engaged with three circumferential grooves 4 a formed near the rear end of the linear guide 4.

Accordingly, the straight guide 4 is extended in conjunction with the differential cylinder 3. At this time, three projections 4c formed at the rear end of the straight guide 4 in the same phase as the straight groove 4b of the straight guide 4 are engaged with the straight groove 2c formed on the inner peripheral portion of the fixed cylinder 2. It moves in the optical axis direction in conjunction with the differential cylinder 3 without rotating.

Reference numeral 6 denotes a one-lens-group holding member for holding one lens group (not shown). At a substantially rear end of the one-lens-group holding member 6, three lenses which engage with the rectilinear grooves 4b of the rectilinear guide 4 are provided. And a pin 7 that engages with a not-shown well-known cam groove formed on the inner peripheral portion of the differential cylinder 3 is fitted into the distal end of the cylindrical projection 6a. .

Reference numeral 8 denotes a two-lens group holding member including a known shutter driving unit and a lens driving unit for focusing on a subject. Similar to the lens group holding member 6, a substantially cylindrical projection 8a engaging with the rectilinear groove 4b of the rectilinear guide 4 and a pin 8b engaging with a cam groove (not shown) formed on the inner peripheral portion of the differential cylinder 3 are integrally formed. Is formed.

Reference numeral 9 denotes a three-lens-group holding member for holding the three-lens group. A substantially cylindrical projection 9a and a pin 9 similar to the two-lens-group holding member 8 are provided on the outer periphery of the three-lens-group holding member.
b is formed integrally.

Then, the one lens group holding members 6, 2
The substantially columnar projections and pins of the lens group holding members 8 and the three lens group holding members 9 are incorporated from behind so as to pass through the inner diameter cutouts 4d of the projections 4c of the linear guide 4. At this time, a cam groove (not shown) formed on the inner peripheral surface of the differential cylinder 3 extends to the rear end in the optical axis direction so that the respective lens group holding members can be incorporated from behind. The phase for incorporating each lens group holding member is outside the zoom range of the camera.

Next, a description will be given of the zooming operation of the zoom lens barrel having the above-described configuration.

When the driving ring 1 is rotated by receiving a driving force from a driving source (not shown), the driving pin 5 engaged with the rectilinear groove 1a is rotated, and at the same time, the differential cylinder 3 is rotated. Since the male helicoid part 3a of the differential cylinder 3 and the female helicoid part 2a of the fixed cylinder 2 are helicoid-coupled, the differential cylinder 3 is extended to the fixed cylinder 2 along the helicoid.

At this time, since the screw tip 5a of the drive pin 5 is engaged with the circumferential groove 4a, the linear guide 4 is extended in conjunction with the differential cylinder 3. The differential cylinder 3 is extended while being rotated with respect to the fixed cylinder 2. However, the linear guide 4 is engaged with the linear groove 2 c formed on the inner periphery of the fixed cylinder 2. 2 will be fed out without rotating.

As a result, the differential cylinder 3 and the rectilinear guide 4 rotate relatively. Each lens group holding member 6,
The rotation of the cylindrical projections 8 and 9 is regulated by the engagement of the columnar projections 6a, 8a and 9a with the rectilinear grooves 4b of the rectilinear guide 4.
Further, since the pins 7, 8b, 9b are engaged with cam grooves (not shown) formed on the inner peripheral surface of the differential cylinder 3, their positions in the optical axis direction are defined.

Therefore, each lens group moves in the optical axis direction along the locus of a cam groove formed in the differential cylinder 3 by the relative rotation of the linear guide 4 and the differential cylinder 3. At this time, the amount obtained by adding the extension amount of the differential cylinder 3 becomes the movement amount of each lens group, and the cam groove on the inner peripheral surface of the differential cylinder is adjusted so that this amount coincides with the amount determined by optical design. Is formed. By the above operation, each lens group performs a predetermined zoom operation.

In the above embodiment, the pins 7, 8b, 9b provided on the lens group holding members 6, 8, 9 are tapered conical rollers. Rollers and other shapes may be used.

In the above embodiment, the substantially columnar projections 6a, 8 formed on the respective lens group holding members 6, 8, 9 are provided.
A and 9a may be square pillars or other shapes as long as they can be engaged with the rectilinear grooves 4b of the rectilinear guide 4.

[0038]

As described above, according to the first aspect of the present invention, a protrusion is provided at the tip of the screw of the drive pin to engage with the circumferential groove of the linear guide to prevent the linear guide from coming off. With such a configuration, it is possible to reduce the number of parts, reduce costs and reduce the number of assembly steps.

According to the second aspect of the present invention, the rectilinear groove of the rectilinear guide is formed to the rear end so that each lens group holding member can be assembled from behind, and the rotation of the rectilinear guide itself is substantially at the rear end of the rectilinear guide. A key-shaped protrusion that regulates the air flow is formed, and the protrusion allows the meat to be connected to the rectilinear groove, so that it is possible to improve the space efficiency, improve the precision of parts, and improve the productivity. .

According to the third aspect of the present invention, the fixed cylinder and the differential cylinder are helicoid-coupled, and the fixed cylinder is formed with an escape groove that matches the helicoid lead and through which the drive pin penetrates. This solves the problem of the mold structure for improving the optical performance. Also, when carrying the camera, when the helicoid comes off due to the impact force when hitting the tip of the camera barrel with a desk or the like, the drive pin contacts the escape groove of the fixed cylinder to absorb the impact force. A camera excellent in impact resistance can be realized, and even if a dent due to the drive pin remains in the escape groove due to the impact force, there is no problem in optical performance.

According to the fourth aspect of the present invention, the pin formed on the outer peripheral portion of the lens holding member is engaged with the rectilinear groove formed in the rectilinear guide. It is excellent and does not require a nut for increasing strength, and is advantageous in terms of space.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing a lens barrel structure of a camera embodying the present invention.

FIG. 2 is an exploded perspective view of the main part.

FIG. 3 is a partial cross-sectional view showing a lens barrel structure of a conventional camera.

FIG. 4 is a cross-sectional view in which a part of FIG. 3 is modified;

FIG. 5 is a partial cross-sectional view showing another lens barrel structure of a conventional camera.

FIG. 6 is an exploded perspective view of FIG. 5;

FIG. 7 is a partial cross-sectional view showing still another lens barrel structure of a conventional camera.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drive ring 2 Fixed cylinder 3 Differential cylinder 4 Linear guide 5 Drive pin 6 1 Lens group holding member 7, 8b, 9b Pin 8 2 Lens group holding member 9 3 Lens group holding member

Claims (4)

(57) [Claims] 1. A fixed barrel that holds a photographic lens optical system and is fixed to a camera body, and is rotatably held on an inner peripheral surface of the fixed barrel, and its rotational phase defines its optical axis direction position. And a linear guide which is positioned on the inner peripheral side of the differential cylinder and whose optical axis direction position is defined corresponding to the position of the differential cylinder, and whose rotational phase is defined by the fixed cylinder. And a drive pin located on the outer peripheral portion of the fixed barrel and fixed to the differential barrel, and a drive ring for applying a rotational force to the drive pin, a circle provided on the rectilinear guide. A lens barrel structure for a camera, wherein a projection for engaging the circumferential groove and rotatably holding the linear guide with respect to the differential barrel and for preventing the linear guide from coming off is provided at the tip of the drive pin. . 2. A fixed barrel that holds a photographic lens optical system and is fixed to a camera body, and is rotatably held on the inner peripheral surface of the fixed barrel, and its rotational phase defines its position in the optical axis direction. And a linear guide which is positioned on the inner peripheral side of the differential cylinder and whose optical axis direction position is defined corresponding to the position of the differential cylinder, and whose rotational phase is defined by the fixed cylinder. And at least two lens group holding members whose rotation is regulated by the rectilinear guide and whose optical position is defined by a cam groove formed in the differential cylinder, wherein the rectilinear guide is the lens group. A lens barrel structure for a camera, comprising a rectilinear groove for restricting rotation of the holding member, and a key for restricting rotation of the rectilinear guide itself being formed in phase with the rectilinear groove. 3. A fixed barrel fixed to a camera body and holding a photographic lens optical system, and held rotatably on the inner peripheral surface of the fixed barrel, and its rotational phase defines its position in the optical axis direction. And a linear guide which is positioned on the inner peripheral side of the differential cylinder and whose optical axis direction position is defined corresponding to the position of the differential cylinder, and whose rotational phase is defined by the fixed cylinder. And a drive pin located on the outer peripheral portion of the fixed barrel and fixed to the differential barrel, and a drive ring that applies a rotational force to the drive pin, wherein the fixed barrel and the differential barrel are A lens barrel structure for a camera, wherein the fixed barrel is helicoidally coupled and has a groove through which the drive pin passes, and the groove is formed so as not to fit with the drive pin. 4. A fixed barrel that holds a photographic lens optical system and is fixed to a camera body, and is rotatably held by an inner peripheral surface of the fixed barrel, and its rotational phase defines its position in the optical axis direction. And a linear guide which is positioned on the inner peripheral side of the differential cylinder and whose optical axis direction position is defined corresponding to the position of the differential cylinder, and whose rotational phase is defined by the fixed cylinder. And a straight groove formed in the straight guide,
In a camera having at least two lens group holding members whose optical position is defined by engaging a pin formed on an outer peripheral portion thereof with a cam groove formed on the differential cylinder, the pin is at least A lens barrel structure for a camera, wherein a part up to a portion engaged with a rectilinear guide is formed integrally with the lens group holding member.