CN1096624C

CN1096624C - Zoom lens barrel

Info

Publication number: CN1096624C
Application number: CN95101468A
Authority: CN
Inventors: 若林央; 町田清贞; 西村知贵
Original assignee: Nikon Corp
Current assignee: Nikon Corp
Priority date: 1994-02-04
Filing date: 1995-01-28
Publication date: 2002-12-18
Anticipated expiration: 2015-01-28
Also published as: CN1115391A; TW265423B; CN1347000A; KR950033629A; MY118937A; KR100296681B1

Abstract

A zoom lens barrel includes at least two lens groups, a linear movement guide tube for guiding a linear movement of the lens groups along the optical axis and a cam tube for reciprocating the lens groups along the optical axis. The guide tube has a guiding portion formed on a film side end portion of the guide tube and extends in parallel with a film surface.

Description

Varifocus lens barrel

The present invention relates to have the Varifocus lens barrel of varifocal type meniscus camera lens (hereinafter referred to as zoom lens), it is convenient to look in the distance and wide-angle is taken a picture apart from scalable between a plurality of lens combination by making.

The recent vest-pocket camera with multiple function, having adopted can be at the zoom lens of freely taking a picture to the scope of wide-angle position from the position of looking in the distance.In addition, wherein the zoom lens retraction camera that can move in camera body has obtained adopting widely, camera is diminished and the requirement of attenuation to satisfy.

Such zoom lens has such structure, and promptly at least two group lens combination are set in the lens drum in the mode that can move back and forth, and changing compound focal length by the distance that changes between the lens combination, thereby can photograph with any zooming rate.

Traditional Varifocus lens barrel with such zoom lens, as among Japanese Patent Application Laid-Open No.4-278932 number announce, comprising: be arranged on the side of camera body and have gathering sill on a plurality of axially extended, outer periphery surfaces of being formed on guide pipe straight line mobile guide pipe; A plurality of lens combination that kept by corresponding lens carrier, this support have the contact pin that inserts in the gathering sill and move back and forth along optical axis; And, be contained in the varifocal cam ring on the outer periphery surface of straight line mobile guide pipe rotationally, and be provided with a plurality of cam paths in this outer periphery surface, these grooves are inserted in the gathering sill respectively with respect to the engagement contact pin of inclined light shaft and wherein corresponding lens carrier.

In order to realize that photography fast and improvement are provided with the operability of the vest-pocket camera of this Varifocus lens barrel, this zoom lens carries out the varifocal operation by this way, be that the CD-ROM drive motor that the varifocal cam ring is assembled in the photography body is rotated, so that lens combination is with the lens carrier to-and-fro movement, thereby changes the distance between the lens combination and change compound focal length.

Figure 15 is the displayed map of this zoom lens cam ring, has shown gathering sill and the shape of cam path and the relation between them of this Varifocus lens barrel.Varifocal cam ring 1 with circumferential length A is used to make two lens combination reciprocating, and has a plurality of cam paths (such as three first cam paths 2 and three second cam paths 3) that are arranged on the periphery surface and are arranged alternately along circumferencial direction.

First cam path 2 is used for making near along first gathering sill 4 of linear movement guide pipe corresponding one of corresponding first lens combination of thing setting and moves back and forth, and forms with the predetermined angle and the tilt zoom groove of optical axis intersection.Be arranged on each engagement contact pin 5 on the lens carrier that is used to keep first lens combination, be meshed with corresponding cam groove 2 and corresponding gathering sill 4.Each second cam path 3 is used for making being arranged on from thing second lens combination far away corresponding along second gathering sill 6 of linear movement guide pipe and moves back and forth.

Each second cam path 3 bends to a shallow V-arrangement so that it comprise one parallel with the film surface of around varifocal cam ring 1, extending the tube retraction slot part 3a of setting and at a predetermined angle with the varifocal groove 3b of optical axis intersection.

Be arranged on each engagement contact pin 7 on the lens carrier that is used to support second lens combination, be meshed with corresponding second cam path 3 by corresponding gathering sill 6.The tube retraction slot part 3a of each second cam path 3 is formed on the side of the wide-angle side of varifocal cam ring 1.

Tube retraction slot part 3a is apart from varifocal groove 3b end far away, is set at first cam path 2 and is positioned on the end on the side of retraction tube, promptly is positioned at first cam path 2 from thing end far away.This makes that when body is photographed in Varifocus lens barrel retraction under the situation of not photographing the distance between two lens combination is as much as possible little, thereby makes camera can be done very little very thinly.

The pitch angle of each varifocal groove 3b (angle between varifocal groove 3b and the film surface) is set greater than the incident angle β of first cam path 2.First gathering sill 4 and second gathering sill 6 are formed on to close proximity each other on the periphery of linear movement guide pipe and are parallel with optical axis, thereby make them limit the rotation of lens combination and define the movement travel of lens combination.

Under the non-photography situation of lens combination retraction photography body, engagement contact pin 5 and 7 is set at first and

second cam paths

2 and 3 ends far away apart from thing, i.e. tube retraction end position a, as shown in figure 15.When varifocal cam ring 1 under this state when the direction shown in the arrow 8 is rotated, engagement contact pin 5 and 7 is moved to wide-angle side (wide-angle position) b, with the distance between two lens combination of zoom lens cam ring.Shift to when looking in the distance photography end (camera positions of looking in the distance) c from wide-angle side b when engagement contact pin 5 and 7, the distance between the lens combination diminishes once more.

Arrow 9 has shown the direction towards thing, i.e. the direction of zoom lens extension.

Up till now, cam ring with for example be connected or the like the urceolus that is arranged on the outside and be meshed by spiral.In the case, for between the tube of removing rotation and the urceolus because spiral is connected or the like the gap of generation, the force application part that is provided with between rotary cylinder and the urceolus such as compression helical spring etc. is set, giving the rotary cylinder application of force, thereby rotary cylinder is contacted in the pressure lower part with urceolus along predetermined direction.

Generally having elastomeric material by stainless steel etc. such as this force application part of compression helical spring makes.Because this extensible material is difficult to processing, the cutting out section of this material has big plastic deformation, thereby is easy to generate tip, burr or the like on this cutting out section.

On the other hand and since the cutting out section of compression helical spring near play a part surface in contact with rotary cylinder or urceolus, most advanced and sophisticated or the like if cutting out section has, rotary cylinder or urceolus will be thrust sometimes in then this tip.Its result, rotary cylinder can not rotate smoothly.

In having the vest-pocket camera of above-mentioned zoom lens, wish that the distance between two lens combination is as best one can little, and more specifically, this distance is substantially zero preferably under the tube retraction state when non-photography, to make the camera of Bao Erxiao.Yet owing to structural reason, being difficult to make the difference between the lens combination as a rule is zero.In these reasons one is to have bigger length with the retraction tube 3a that each second cam path 3 forms.When lens combination have the big retraction length that begins from wide-angle side position b maybe when the stroke zoom lens cam ring that begins from wide-angle side position b so that photography body attenuation and when making the camera compactness, even the stroke and the angle of rotation of first and second cam paths are equal to each other, the length of tube retraction slot part 3a shown in Figure 16 is also greater than shown in Figure 15, this makes the tube retraction side a of each first cam path 2 disturb mutually with the wide-angle side b of corresponding tube retraction slot part 3a, thereby feasiblely is difficult to stretch out and withdraw lens combination.

If the diameter that reduces lens drum is so that the camera compactness, then varifocal cam ring 1 ' as shown in figure 17, around length B become shorter too much than varifocal cam ring shown in Figure 15 1.When first and second cam paths 2 shown in Figure 17 with 3 with shown in Figure 15 when identical, it is big that the angle of rotation of varifocal cam ring 1 ' becomes.In addition, first and

second cam paths

2 and 3 pitch smaller, and their tube retraction side a thereby produced interference each other.

When the angle of inclination beta on first cam path 2 and film surface be set greatly when addressing these problems, the angle of rotation of varifocal cam ring 1 ' can be very little in whole stroke, and can prevent that first and

second cam paths

2 and 3 from producing interference each other.Yet, in the case, big angle of inclination beta zoom lens cam ring the rotation load that varifocal cam ring 1 ' is rotated.Therefore, the CD-ROM drive motor of big driving power need be provided, thereby stop the miniaturization of having harmed camera.This do not meet reduce lens diameter so that the purpose of camera compactness.

The present invention makes in this case, and one object of the present invention, provide a kind of having simply and the Varifocus lens barrel of compact structure, and this Varifocus lens barrel can be by shortening or not adopting the tube retraction slot part of each cam path to prevent interference between the cam path, and can reduce to drive load.

In order to achieve this end, in this Varifocus lens barrel, change distance between a plurality of lens combination along the optical axis to-and-fro movement by making lens combination, change compound focal length; This Varifocus lens barrel comprises: at least two lens combination; Be used for guiding the straight-line linear movement guide pipe of described lens combination along optical axis; Make described lens combination along the reciprocating cam ring of described optical axis with being used to; And the targeting part that guide pipe has that the film side that is formed on this guide pipe is partly gone up and extend abreast with the film surface.

In the present invention, from the parallel slot that gathering sill extends, formed tube retraction slot part basically.Therefore, cam groove drum retraction amount can access shortening, and can prevent the interference between the adjacent cam path.

Because the parallel slot of Varifocus lens barrel of the present invention extends from the film end of the gathering sill of linear movement guide pipe, with with film surface at least one lens combination that leads abreast, and each parallel slot has cam path film end corresponding with each gathering sill when the tube retraction, so tube retraction slot part can be shortened.Therefore, even between wide-angle side position and the tube retraction end position apart from the zoom lens cam ring so that the camera attenuation, also can prevent the interference between the cam path, thereby still can guarantee the extension and the contraction of the length that is shortened between a retraction slot part and the lens combination.Need reduce the external diameter of lens drum so that the size decreases of camera particularly makes its height and width diminish.Because the interference between the cam path can not take place in the present invention, so the decrease of the external diameter of lens drum can equal a decrease of retraction slot part.Little external diameter has reduced the load of varifocal cam ring.This diminishes CD-ROM drive motor, thereby can obtain compactness and light camera.

Second purpose of the present invention is by a kind of Varifocus lens barrel being provided, further improving above-mentioned the present invention; In this Varifocus lens barrel, the engagement contact pin is successfully moving between linear travel slot and a parallel slot with little driving power.

The invention provides a kind of Varifocus lens barrel, be used for changing compound focal length by moving a plurality of lens combination forward and backward with respect to optical axis direction with the distance that changes between the described lens combination, this Varifocus lens barrel comprises:

A plurality of lens carrier parts are used for supporting respectively described a plurality of lens combination;

A linear movement guide pipe, being fixed is provided with to be meshed with described a plurality of lens carrier parts respectively and to have a plurality of linear travel slot of extending along parallel with optical axis basically direction; And

The varifocal cam ring, it has a plurality of cam paths, these cam paths are respectively with described a plurality of lens carrier parts engagement, incline towards each other and have the rearmost end part that the end in the film side stops towards optical axis direction, and this varifocal cam ring is contained in the described linear movement guide pipe rotationally so that can move to a varifocal position and a tube retracted position

Wherein said guide pipe has a parallel slot, this parallel slot be parallel to film surface and be connected with the distolateral dwell section of film of at least one gathering sill of described a plurality of linear travel slot, vertical with the axle of described guide pipe, also when described cam ring is in a tin retraction state and the film side final end of respective cams groove divide overlaid.

The well width of the coupling part between described linear travel slot and described parallel slot, more preferably greater than described linear travel slot or width or the width of described parallel slot.

On the periphery of the coupling part between described linear travel slot and the described parallel slot, be preferably formed as an inside circumference part that is substantially arc.

By above-mentioned Varifocus lens barrel according to the present invention, when mate moves by the coupling part between linear travel slot and the parallel slot, to compare with the situation that two grooves intersect each other, the resistance that the engaging piece branch applies reduces.Therefore, mate can successfully move between linear travel slot and parallel slot, and can rotate the varifocal cam ring by enough little driving powers.

Another aspect of the present invention relates to successfully rotates a rotating cylinder in a lens drum; This lens drum utilizes a force application part to this rotating cylinder application of force.

To achieve these goals, a lens drum according to the present invention comprises: a rotating cylinder, and it rotates on optical axis to support photographic optical system; A force application part is used for along predetermined direction described rotating cylinder being carried out the application of force; A receiving-member is used to receive described force application part; And, intermediary's parts, it is set between described force application part and described rotating cylinder and/or described force application part and the described receiving-member, to be resisted against on described rotating cylinder and/or the described receiving-member by described force application part and can be free to slide with respect to described force application part and/or described receiving-member.

Described intermediary parts comprise that one is used to block from the light of a part of incident light of described photographic optical system incident and blocks parts.Described force application part is a compression helical spring.

Described photographic optical system is a focus lens group or forms at least one group in a plurality of groups of zoom lens group.

According to the present invention, these intermediary's parts be set at force application part or the contacted rotating cylinder at least of receiving-member on.If on the end of force application part and rotating cylinder, have most advanced and sophisticated or the like and rotating cylinder therein force application part be inserted in its parts that contact with it,, then intermediary's parts, rotating cylinder and/or receiving-member are relatively rotated.Therefore, can successfully rotate rotating cylinder.

Fig. 1 is the overall longitudinal sectional view of an embodiment when being in the retraction state according to Varifocus lens barrel of the present invention;

Fig. 2 is the overall longitudinal sectional view of the embodiment of Fig. 1 when being in the wide-angle state;

Fig. 3 is that the embodiment of Fig. 1 is in the overall pattern when looking in the distance state.

Fig. 4 is the varifocal cam ring of Varifocus lens barrel of Fig. 1 and the displayed map of linear movement guide pipe, has shown the shape of gathering sill and cam path and the relation between them;

Fig. 5 is the linear movement guide pipe of Fig. 4 and the varifocal cam ring synoptic diagram when being in the wide-angle state;

Fig. 6 is according to the varifocal cam ring of another embodiment of Varifocus lens barrel of the present invention and the synoptic diagram of linear movement guide pipe, has shown gathering sill and cam path shape and the relation between them;

Fig. 7 is varifocal cam ring shown in Figure 5 and the linear movement guide pipe synoptic diagram when being in the wide-angle state;

Fig. 8 has shown the relation between the them when shape of gathering sill and cam path and they are in a tin retraction state;

Fig. 9 has shown the wide-angle state of Fig. 8;

Figure 10 A to 10C has shown another embodiment, has shown the shape of coupling part 25;

Figure 11 is a cut-open view, has shown the setting of first embodiment of camera, has wherein used lens drum of the present invention;

Figure 12 is a cut-open view, has shown to be in a setting of the camera of retraction state, has wherein used second embodiment of lens drum of the present invention;

Figure 13 has shown the situation the when camera in the cut-open view of Figure 12 is in the wide-angle state;

Figure 14 has shown that the camera in the cut-open view of Figure 12 is in the situation when looking in the distance state;

Figure 15 is cam path and the shape of gathering sill and the synoptic diagram of the relation between them of traditional Varifocus lens barrel;

Figure 16 has shown that traditional zoom is apart from the interference between the cam path of lens drum;

Figure 17 has shown that the another kind between the cam path of traditional Varifocus lens barrel disturbs.

In conjunction with the accompanying drawings and by most preferred embodiment the present invention is described now.

Fig. 1 is the overall longitudinal sectional view of an embodiment according to Varifocus lens barrel of the present invention when being in a tin retraction state.

Fig. 2 is the overall longitudinal sectional view of this Varifocus lens barrel when being in the wide-angle state.

Fig. 3 is that this Varifocus lens barrel is in the overall longitudinal sectional view when looking in the distance state.

Figure 4 and 5 are synoptic diagram, have shown gathering sill and the shape of cam path and the relation between them of this Varifocus lens barrel.Fig. 4 has shown that their tube retraction state and Fig. 5 have shown their wide-angle state.

In Fig. 1 to 3, comprise a main photograph machine frame 11, Varifocus lens barrel 12, a photographic roll film 13 and constitute first and

second lens combination

14 and 15 of the zoom lens of photographic optical system by the camera body of 10 expressions.

At the core of main photograph machine frame 11, be formed with a shutter 16, and a tubular linear movement guide pipe 17 that is connected with shutter 16 is integrally formed on the main photograph machine frame 11 and from its rear end and stretches out forward.After shutter 16, be provided with film passage 18, film 13 is advanced by it.

Varifocus lens barrel 12 comprises the linear movement guide pipe 17 that stretches out from main photograph machine frame 11, is arranged on first and

second lens combination

14 and 15 the linear movement guide pipe 17, is contained in the varifocal cam ring 19 on the outer periphery surface of linear movement guide pipe 17 and be used to rotate the CD-ROM drive motor (not shown) of varifocal cam ring 19 rotationally in reciprocating mode.

On the periphery surface of linear movement guide pipe 17, be provided with many group gathering sills (being three

first gathering sills

20 and 3 second gathering sills 21 in the case) equidistantly along circumference.Each first gathering sill 20 comprises the straight-line groove that be arranged in parallel with optical axis L and limits the rotation of first lens combination 14 and define its movement travel.Each second gathering sill 21 comprise a straight-line groove parallel similarly with optical axis L and be formed on corresponding first gathering sill 20 near.

As shown in Figure 4, one with the vertical and parallel parallel slot 22 of the axle of linear movement guide pipe 17 with photographic roll film 13, from the film side 21a of each second gathering sill 21 along with towards the opposite direction extension of adjacent first gathering sill 20.This set is different with each traditional direction groove 6, as shown in Figure 8.Referring to Fig. 4, each parallel slot 22 has suitable length, thereby makes the tube retraction side a of tube retraction side of second that its front end and each will be described below, as to constitute varifocal cam ring 19 cam path 24 overlapping.

As shown in Figure 1, first lens combination 14 is set in first lens carrier 26 by light hurdle 27.First lens carrier 26 is inserted in the linear movement guide pipe 17 slidably.Three engagement contact pins 28 from the rearward end of first lens carrier 26 outer periphery surface stretch out, and be meshed with first gathering sill 20 in being formed on linear movement guide pipe 17, move thereby first lens carrier 26 is inserted in the linear movement guide pipe 17 and along optical axis L slidably, but its rotation is restricted (Fig. 4).

Second lens combination 15 supports and is set at after first lens combination 14 by second lens carrier 29.Second lens carrier 29 is placed on the rear side of first lens carrier 26 and is inserted into slidably in the linear movement guide pipe 17.Three engagement contact pins 30 stretch out and are inserted in second gathering sill 21 that is formed on the linear movement guide pipe 17 from the rearward end of second lens carrier 29, thereby second support 29 is moved but its rotation is restricted along optical axis L.Between first lens carrier 26 and second lens carrier 29, be provided with a compression helical spring 32, this spring is given second lens combination, 15 application of forces backward, shakes to prevent it.

Varifocal cam ring 19 is contained on the outer periphery surface of linear movement guide pipe 17 rotationally, and be set on the film side end of its outer periphery surface, and a flange portion 19a is slidably to be supported by the front end of an annular support member 33 and main photograph machine frame 11 with rotating mode.

On the close part of flange portion 19a of the outer periphery surface of varifocal cam ring 19, be provided with gear 34.Three first cam paths 23 and three second cam paths 24 alternately also are formed on the inner periphery surface of varifocal cam ring 19 equidistantly.

First cam path 23 has formed the tilt zoom groove with respect to optical axis L, is used to receive the end of engagement contact pin 28 and be used to make first gathering sill 20 to-and-fro movements of first lens combination 14 along linear movement guide pipe 17.Second cam path 24 is used to make second gathering sill 21 to-and-fro movements of second lens combination 15 along linear movement guide pipe 17, and its each all be made into shallow V-shaped groove, they comprise first retraction slot part 24a that extends along the circumference of the varifocal cam ring 19 parallel with the film surface and the second zooming slot 24b that tilts at a predetermined angle with respect to optical axis L.Engagement contact pin 30 is inserted in corresponding second cam path 24 by the end of corresponding second gathering sill 21.First and second cam paths 23 are identical with tradition first and

second cam paths

2 and 3 shown in Figure 15 with 24, and the tube retraction groove 24a that is second cam path 24 of the present invention is shorter than the length of the parallel slot 22 of the second traditional cam path 3.

As shown in Figure 1, support component 33 is fixed on the front surface of main photograph machine frame 11 by a bolt 35, and supports a gear 36 that is meshed with the gear 34 of varifocal cam ring 19 rotationally.In the varifocal operation, gear 36 obtains by the CD-ROM drive motor (not shown) rotating, to stretch out selectively and the varifocal cam ring 19 of withdrawing.

Have the retraction cartridge type camera of aforesaid Varifocus lens barrel 12, have suitable structure, thereby under tube retraction state as shown in Figure 1, first lens carrier 26 is moved in the linear movement guide pipe 17 of camera body 1 fully.Under tube retraction state as shown in Figure 4, each engagement contact pin 28 is positioned at the film side end of first gathering sill 20, and each engagement contact pin 30 of second lens carrier 29 is positioned at the front end of parallel slot 22 of corresponding gathering sill 21 and the film side end a of corresponding second cam path 24.

When varifocal cam ring 19 when the bearing of trend of the varifocal cam ring 19 shown in the arrow 40 of Fig. 4 rotates, first cam path 23 is shifted to the left side and is arrived state shown in Figure 5 from the state of Fig. 4.Each engagement contact pin 28 is upwards pushed away by the lower surface of corresponding first groove 23 in Fig. 4, and the axial component that is pressed in the power of engagement on the contact pin 28 makes engagement contact pin 28 move towards thing along corresponding first gathering sill 20.Therefore, first lens combination 14 is advanced with first lens carrier 26 and is reached outside the camera body 10 from linear movement guide pipe 17.

When varifocal cam ring 19 when the bearing of trend of varifocal cam ring 19 rotates, second cam path 24 is moved to the left.Therefore, each engagement contact pin 30 is moved toward wide-angle side position b and is in the equitant state of respective barrel retraction slot part 24a of parallel slot wherein 22 and corresponding second cam path 24.Because each parallel slot 22 is parallel with the film surface with tube retraction slot part 24a, engagement contact pin 30 can not advance along second gathering sill 21, and second lens combination 15 is maintained at a retracted position.Varifocal cam ring 19 rotates the corresponding angle of length with first retraction slot part 24a, thereby make engagement contact pin 30 can move to the wide-angle side b of retraction slot part 24a, thereby make first and

second lens combination

14 and 15 be placed in the wide-angle state, as shown in Figure 2.

When varifocal cam ring 19 when the bearing of trend along varifocal cam ring 19 rotates from the wide-angle state,

engagement contact pin

28 and 30 moves towards thing along first and

second gathering sills

20 and 21, and stop at the position c that looks in the distance, thereby make first and

second lens combination

14 and 15 get the state of looking in the distance, as shown in Figure 3.

When CD-ROM drive motor along being activated in the opposite direction with when the direction of withdrawal is rotated varifocal cam ring 19 with above-mentioned side,

engagement contact pin

28 and 30 is shifted to film along the gathering

sill

20 and 21 of first and second gathering sills 20 and 21.First and

second lens combination

14 and 15 are withdrawn in the linear movement guide pipe 17, thereby turn back to a retraction state.

In the present embodiment, each parallel slot 22 vertical with optical axis L is from the film side end extension of corresponding second gathering sill 21.Because each parallel slot 22 has the identical functions with tube retraction slot part 24a, the length of each retraction slot part 24a can be shortened the length of each parallel slot 22.In this lens combination under the big situation of the tube retraction amount of wide-angle side position b, or the stroke from wide-angle position b to the tube retracted position increases under the situation of the compactness so that camera body is thin therein, even the angle of rotation of first cam path 23 and stroke equate with second cam path 24, also can prevent the interference between

cam path

23 and 24 surely.Therefore, first and

second lens combination

14 and 15 can be stretched out surely and withdraw.Because each parallel slot 22 plays a part a retraction slot part, it is big that the distance between first and

second lens combination

14 and 15 can not become when the tube retraction.

The tube retraction slot part 24a of each second cam path 24 and separating of corresponding first cam path 23 are than the length of separating big parallel slot 22 between the tube retraction slot part 3a of second cam path 3 of Figure 15 and first cam path 2.Therefore, the camera compactness even the diameter of this lens drum is reduced does not need to increase the angle of inclination beta between first cam path 23 and the film surface yet, thereby has prevented the interference between first and second cam paths 23 and 24.When angle of inclination beta hour, the rotation load that is used to rotate varifocal cam ring 19 is also little.Therefore, can adopt little CD-ROM drive motor.

During moving from tube retracted position a to wide-angle position b, engagement contact pin 30 will shake by the circumferencial direction along varifocal cam ring 19 in parallel slot 22, and

lens carrier

28 and 29 will rotate.Yet second lens 15 do not change its position and shape when being subjected to external force, because second lens combination 15 is set in the linear movement guide pipe 17.In addition, engagement the shaking of contact pin 30, by by a spring and along a direction to its application of force, and can be eliminated.

Fig. 6 and 7 is synoptic diagram of another embodiment of the present invention, has shown the relation between gathering sill and the cam path.Fig. 6 has shown that tube retraction state and Fig. 7 have shown the wide-angle state.In this embodiment, 24 of each second cam paths are made of a straight line zooming slot with respect to inclined light shaft, and a tube retraction slot part 24a shown in Figure 4 has been omitted.A parallel slot 22 extends to the film side end of corresponding second cam path 24 from the film side end of each second gathering sill 21, thereby makes parallel slot 22 be used as a retraction slot part.Other structures of second embodiment are basically the same as those in the first embodiment.

In a second embodiment, second cam path 24 does not have a retraction slot part.What therefore, the pitch angle a of second cam path 24 of second embodiment can be than first embodiment is little.Load when little pitch angle a can reduce to drive the varifocal cam ring, and make the motor miniaturization.Because the second zooming slot 24b pitch angle a diminishes, the length of cam can be increased and the precision of cam is improved.When second cam path 24 did not have a tin retraction slot part, engagement contact pin 30 did not shake, and has prevented the rotation of

lens carrier

28 and 29.

Embodiment by Varifocus lens barrel has described the present invention, and its each embodiment has two

lens combination

14 and 15, but the present invention is not limited only to this.Naturally, the present invention can be applied to and have three or the Varifocus lens barrel of poly-lens group more.

By above-mentioned setting, even the stroke from wide-angle position to the tube retracted position increases, also can prevent the interference between

cam path

23 and 24, the thickness of camera can access and reduce, and the external diameter of lens drum can access and reduces.

Yet, because when varifocal cam ring 19 rotates and mesh 90 ° of the direction flip-floies that contact pin 30 moves along the direction of arrow 40 when parallel slot 22 is shifted to gathering sill 21 (Fig. 6), in some cases, according to the gap value of parallel slot 22, the sliding resistance that is added on the engagement contact pin 30 becomes big.Therefore, need to set the driving power that is used for varifocal cam ring 19 carries out the CD-ROM drive motor of rotating drive greatlyyer to a certain extent.Its result can not use small-sized CD-ROM drive motor, and this has harmed the compactness of device.

Following embodiment proposes for addressing this problem, and will in conjunction with Fig. 8,9 and Figure 10 A to 10C described.With described different settings is set, identical with being provided with of describing in the aforementioned embodiment.

Fig. 8 and 9 is respectively the synoptic diagram of linear movement guide pipe 17 and varifocal cam ring 19 under a retraction state and the wide-angle state, is used to show the shape of guide cam and cam path and the relation between them.

Referring to Fig. 8, first and

second gathering sills

20 and 21 are formed on the periphery surface of linear movement guide pipe 17 equidistantly along circumferencial direction (right side and the left in the figure respectively).Though in Fig. 8, do not show, formed a plurality of first and second gathering sills 20 and 21 (for example three) respectively along circumferencial direction.

The inside circumference of the coupling part 25 between the film side end of the side of first gathering sill 20 of parallel slot 22 and second gathering sill 21, be made into to be essentially arc, under first gathering sill 21 and situation that the inside circumference of parallel slot 22 is perpendicular to one another basically, to be positioned on the interior location beyond the intersection location.Therefore, the well width of coupling part 25 is bigger than the well width of first gathering sill 21 or parallel slot 22.Present embodiment is different with previous embodiment, only is the setting of this coupling part.

In the present embodiment, because the inside circumference of the coupling part 25 between second gathering sill 21 and the parallel slot 22 is essentially arc and well width coupling part 25 is increased, so when engagement contact pin 30 passed through coupling part 25, the sliding resistance of engagement contact pin 30 reduced.Therefore, the load when varifocal cam ring 19 is driven on it is reduced, thereby the varifocal cam ring can more successfully be rotated.

On the other hand, owing to have only the inside circumference of coupling part 25 to be made into arc basically, the gap between engagement contact pin 30 and the coupling part 25 becomes bigger near wide-angle side.Yet, after Varifocus lens barrel 12 is moved by the varifocal operation, Varifocus lens barrel is along the direction of varifocal cam ring 19 tension first lens carrier 26 and stopped surely, with for varifocal cam ring 19 is controlled and eliminated it and shake.Therefore, engagement contact pin 30 is resisted against on the neighboring (outside) of coupling part 25, with the unevenness that prevents to shake the position of second lens combination 15 that causes owing to described.

Figure 10 A to 10C has shown the correction shape of coupling part 25.Figure 10 A has shown the neighboring that is formed the coupling part 25 of arc in the mode identical with inside circumference substantially.Therefore, in this example, the well width of second gathering sill 21, coupling part 25 and parallel slot 22 is substantially the same.Figure 10 B has shown the inside circumference that is made into coupling part 25 straight and that tilt with respect to gathering sill 21 and parallel slot 22 substantially.Figure 10 C has shown the coupling part 25 that has Figure 10 B that is essentially rectilinear inclination neighboring.

Even when coupling part 25 is formed in such a manner, engagement contact pin 30 also can successfully move between second gathering sill 21 and parallel slot 22.

Present embodiment is to form like this, even the resistance that proper mate is added on the mate when advancing by the coupling part between linear travel slot and the parallel slot can be less, mate can successfully move and can rotate the varifocal cam ring with little driving power.In this way, the size of CD-ROM drive motor can be reduced, and camera can be compact and light.

Below, another embodiment of the present invention will be described, wherein rotating cylinder can access more smoothly and rotate.

Referring to Figure 11, urceolus 57 can obtain camera main frame 56 rotationally and be fixed to the support of the pressing plate 58 on the camera main frame 56 by a mounting screw 59 around optical axis L.The inside circumference of urceolus 57 is provided with a female screw face 57a, and its neighboring is provided with a driven wheel 57b.Driven wheel 57b is meshed with the gear 61 that is arranged on urceolus 57 outsides.

On the part of the neighboring of inner core 60, be provided with a male screw face 60a, and the female screw face of the latter and urceolus 57 mutually spiral connect.The rotation of inner core 60 is by pin 56a restriction, and pin 56a extends from camera main frame 56.

At inner core 60 internal fixation a light hurdle part 53 is arranged.The inside circumference of light hurdle part 53 partly is provided with a female screw face 53a.

And, on the part of the neighboring of lens carrier 52, be provided with a male screw face 52a, be used to support photographic lens 51 and with the female screw face 53a of light hurdle part 53 mutually spiral connect.

Between a receiving unit 53b of the rearward end 52b of lens carrier 52 and light hurdle part 53, be provided with a compression helical spring 62.Compression helical spring 62 is subjected to the application of force by this way, so that the receiving unit 53b of the rearward end 52b of lens carrier 52 and light hurdle part 53 is isolated.Its result, lens carrier 52 is subjected to the application of force along the direction of optical axis (left to the figure), to remove the gap that produces between female screw face 53a and male screw face 52a.

In addition, between the receiving unit 53b of compression helical spring 62 and light hurdle part 53, accompany a pad 63.Pad 63 comprises a rising part 63a and a smooth part 63b, and compression helical spring 62 is pressed on the smooth part 63b, thereby makes pad 63 contact with receiving unit 63 basically under the effect of pressure and can successfully slide with respect to receiving unit 63b by the application of force of compression helical spring 62.

When gear 61 was rotated by the driving operation of CD-ROM drive motor (not shown), urceolus 57 rotated around optical axis L, thereby the rotation of inner core 60 is restricted, and moved thereby inner core is slided along the direction of optical axis L.

In addition, light hurdle part 53, in response to the signal distance of the thing that will photograph of expression, that send from a distant journey measurement mechanism (not shown), rotate lens carrier 52, and photographic lens 51 rotates mobile under the guiding of sun and

female screw face

52a and 53a along the direction of optical axis L, thereby carries out focusing operation.

Here, when lens carrier 52 rotates and when the direction of optical axis L moves, the end of compression helical spring 62 has the inhomogeneous of tip or other and bites or adhered to the rearward end 52b or the pad 63 of lens carrier 52.When these two parts can not be relative to smooth moving, between the receiving unit 53b of pad 63 and light hurdle part 53, produced a relative slip.Therefore, lens carrier 52 always can successfully rotate around optical axis L.

Figure 12 to 14 is cut-open views, has shown the setting of the camera of having used another embodiment of the present invention; Rotating cylinder can successfully rotate at the wide-angle state and the state of looking in the distance respectively in this embodiment.

The embodiment of Figure 12 to 14 is different with the embodiment's shown in Fig. 1 to 3, is that it comprises: a receiving-member, and it receives the force application part that is used for the rotating cylinder application of force; And intermediary's parts, it is set between this force application part and this receiving-member, and is resisted against on the receiving-member by this force application part, and can slide with respect to receiving-member.The embodiment's of other setting and Fig. 1 to 3 is identical.Below above-mentioned difference will be described.

Between first lens carrier 26 and second lens carrier 29, be provided with a compression helical spring 32 by pad 40.Compression helical spring 32 is upwards to second lens combination, 15 application of forces, to prevent shaking of this second lens combination 15.Pad 40 can successfully slide with respect to second lens carrier 29, and by the application of force of compression helical spring 32 and closely contact with second lens carrier 29.

If there is not pad 40, then in some cases can be by the rotation of second lens carrier 29 and bites or attached to the base 26a or the flange 29a of first lens carrier 26 in the end of the base of compression helical spring 32.Therefore can not obtain the smooth rotation of second lens carrier 29.At this moment, when pad 40 is set between second lens carrier 29 and the compression helical spring 32, even produced any interlock between the end of the position 26a of first lens carrier 26 and compression helical spring 32 or between the end of pad 40 and compression helical spring 32 or adhere to fashionable, between the pad 40 and second lens carrier 29, produced slip, and second lens carrier 29 can rotate around optical axis L successfully.

In the embodiment shown in fig. 11, between the receiving unit 53b of compression helical spring 62 and light hurdle part 53, be provided with pad 63.Yet the position of this pad is not limited only to this.This pad can be set between the rearward end 52b of compression helical spring 62 and lens carrier 52.In the case, this pad can be set up in these positions, or can be arranged on these two positions simultaneously.In an identical manner, in the embodiment shown in Figure 12 to 14, pad 40 can be set between the position 26a of the compression helical spring 32 and first lens carrier 26.

In addition, the smooth part 63b of pad 63 extends along the direction of optical axis in the embodiment shown in fig. 11, perhaps the smooth part of pad 40 extends to the inside circumference part 26b of first lens carrier 26 in a second embodiment, blocks parts thereby make described smooth part can be used as light.

By the lens drum shown in Figure 11 to 14, by intermediary's parts are set, even at force application part by interlock or adhere under the situation that is combined in relative parts, also can successfully rotate rotating cylinder.In this way, the positional precision of rotating cylinder can be further improved in the rotating drive operation.

Claims

1. a Varifocus lens barrel comprises: two lens combination at least; Be used for guiding the straight-line linear movement guide pipe of described lens combination along optical axis; Make described lens combination along the reciprocating cam ring of described optical axis with being used to; And the targeting part that guide pipe has that the film side that is formed on this guide pipe is partly gone up and extend abreast with the film surface.

2. a Varifocus lens barrel is used for changing compound focal length by moving a plurality of lens combination forward and backward with respect to optical axis direction with the distance that changes between the described lens combination, and this Varifocus lens barrel comprises:

3. according to the Varifocus lens barrel of claim 2, wherein at least one inside circumference of the periphery of the coupling part between described linear travel slot and described parallel slot partly is positioned on the inboard, rather than is positioned on the intersection location that described linear travel slot intersects with described parallel slot substantially.

4. according to the Varifocus lens barrel of claim 2, the well width of the coupling part between wherein said linear travel slot and the described parallel slot is greater than the width of described linear travel slot or the width of described parallel slot.

5. according to the Varifocus lens barrel of claim 2, at least one inside circumference part of the periphery of the coupling part between wherein said linear travel slot and the described parallel slot is made into arc substantially.

6. according to the Varifocus lens barrel of claim 3, at least one inside circumference part of the periphery of the coupling part between wherein said linear travel slot and the described parallel slot is made into arc substantially.

7. according to the lens drum of claim 2, further comprise:

Force application part is used for along predetermined direction the described lens carrier parts application of force;

Receiving-member is used to receive described force application part; And

Intermediary's parts, it is set between described force application part and the described cam ring and/or between described force application part and the described receiving-member, be resisted against on described cam ring and/or the described receiving-member, and can be free to slide with respect to described cam ring and/or described receiving-member by described force application part.

8. according to the lens drum of claim 7, wherein said intermediary parts have the shading light part that is used to block the incident light that a part enters by described lens combination.

9. according to the lens drum of claim 7, wherein said force application part is a compression helical spring.