CN2114179U

CN2114179U - Sunshade for zoom lenses

Info

Publication number: CN2114179U
Application number: CN 92203583
Authority: CN
Inventors: 高成华
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-02-29
Filing date: 1992-02-29
Publication date: 1992-08-26

Abstract

The utility model relates to a lens hood for zoom lenses. The hood body is formed by the lap of a plurality of laminas. Under the function of a uniform-distributing external force, all the laminas can synchronously changes the flare angles corresponding to the shaft line of the hood body. When the flare angles become bigger, the conicity of the hood body also becomes bigger and the shading angle becomes bigger with the conicity of the hood body. When the flare angles become smaller, the conicity of the hood body also becomes smaller and the shading angle becomes smaller with the conicity of the hood body. The process of the transition of the hood body from the extreme of the positive cone to the extreme of the negative cone realizes the light shade from the ultra wide angle to the ultra long focal length. Whereas, the exertion of the uniform-distributing external force only rotates the adjusting ring for the flare angles of the lens hood. If the lens hood for zoom lenses and the zoom lens ring of the video camera are added a connecting mechanism, the pursuing and follow-up action of the shading angle and the viewing angle can be realized. The utility model can be multi-functional in accordance with the replacement of lens hood bases of different sizes or structures of the lens.

Description

Sunshade for zoom lenses

The utility model relates to the dimmer that is exclusively used in the photography purposes, particularly eliminates the light shield of harmful light from camera lens.

At present, the light shield of selling on the market, using all is the fixing device that is attached to certain close-up, wide-angle lens and telephoto lens, because the requirement of its field angle, each can only use its affiliated special-purpose assorted light shield.The camera of being furnished with several camera lenses must dispose several corresponding light shields, not so, is not influence picture complete, does not have interception exactly.When using zoom lens, in fact need a kind of can be with camera lens at wide-angle to the adjustable light shield that changes between the long burnt state, the video camera of particularly big multiple proportions zoom, often continually that camera lens is burnt to length from the wide-angle push-and-pull, the servo-actuated light shield particularly is suitable for and is necessary.Yet the light shield of existing zoom lens all is to design for prerequisite with the field angle of not blocking minimum focus, and therefore, such light shield can only work when camera lens works in the wide-angle state, when length is burnt, has not had shaded effect.The shown invention main points of CN88204404 last disclosed " variable light shield " though can deacclimatize the duty of camera lens by flexible light shield length, in only being applicable to, the camera lens of long-focus, and are wanted adapted shade or shading aperture at its front end.This not only still can not solve from wide-angle to the shading problem of the more frequent scope of this section of Jiao camera lens work, and troublesome poeration.

The purpose of this utility model, to make camera lens exactly, the camera lens of particularly big multiple proportions zoom, work under any state between overlength Jiao or during at super wide-angle in this interval frequent changes duty, it is complete that light shield can both neither influence picture, injecting of blocking harmful light to greatest extent again, and realize of the tracking servo-actuated of required lamp shielding angle to the lens focus frequent variations.

The technical solution of the utility model is: some blades are overlapping successively, fuse with flexible material in root, become a closed lighttight cover body with moving vane, under the effect of uniform external force, form the blade of cover body and can be synchronously change its subtended angle with respect to the axis of cover body, when subtended angle became big, it is big that the cover body tapering also becomes, lamp shielding angle becomes greatly thereupon, otherwise promptly anti-.Cover body carries out the transition to minimum taper from maximum taper, promptly carries out the transition to the process of the back taper limit from the positive cone limit, has just realized the shading from super wide-angle to overlength Jiao.See accompanying drawing 3.When the size of mirror head outer shell or structure not for the moment, only need to change the web member of lens hood and camera lens, just can shared same light shield.Increase the interlinked mechanism of light shield, just can realize the servo-actuated of the lamp shielding angle and the angle of view to video camera zoom ring.

A kind of light shield that is used for zoom lens described in the utility model, the scope of application is big, good shading effect, easy and simple to handle, and can realize step-less adjustment, both can use separately on camera, respective seat is changed in the realization servo-actuated that can be connected with video camera again, also can a cover uses.

Fig. 1 is the axial cut-open view of this light shield.

Fig. 2 is this light shield radial cross-section.

Fig. 3 is this light shield work synoptic diagram.

Below in conjunction with accompanying drawing, talk an embodiment.

Plurality of rubber blade 9 is overlapped into a closed lighttight cylindrical shell successively, and all blades 9 fuse in root, are fixed between main base frame 2 and the trim ring 7.Trim ring 7 is used thread connection with main base frame 2.In the outside of main base frame 2, uniform 3 keyways are equipped with the lifting circle 4 with corresponding feather key, and on each blade 9 of main base frame 2 one ends, a pre-buried hinged-support 8 respectively by connecting rod 10, links to each other with the hinged-support 8 of relevant position on the lifting circle 4.With screw 13 subtended angle adjusting ring 6 is axially fixed between cover plate 5 and the main base frame 2, turn subtended angle adjusting ring 6, lifting circle 4 rely on the screw thread of itself and subtended angle adjusting ring 6 to pay, and realize moving up and down.The result that lifting circle 4 moves up and down is drawing blade 9 relative cover body axial wobbles, thereby realizes the variation of cover body lamp shielding angle.Base 12 1 ends connect with cover body, and the other end connects with camera lens 19, with the end that base 12 combines with camera lens 19, make the various forms that adapts with camera lens, when the size of mirror head outer shell or structure not for the moment, change corresponding base 12 and just can accomplish that a cover more and use.Base 12 with connecting of cover body is, spring 3 and sliding plug 1 are placed two symmetric positions of main base frame 2, and sliding plug 1 passes trim ring 7 and inserts in the water jacket of bases 12 under the effect of spring 3, add that trim ring 7 and key, the groove of base 12 limit, base 12 is positioned and is locked on the cover body.When need are driven lower bottom base 12, promote to be installed in the shifting block 11 of main base frame 2, its other end promptly rotates around its binding site with main base frame 2, until making sliding 1 groove that withdraws from base 12 fully of filling in, can deviate from base 12 through sliding plug 1 compression spring 3.When using big multiple proportions zoom shot machine, for reaching the tracking servo-actuated of lamp shielding angle and field angle, will increase by one between light shield and video camera can be at the connect mechanism of axial stretching, this mechanism is by trace 14 and interlock fork 15, nut 16, packing ring 17 is formed, trace 14 and interlock fork 15 is respectively fixed on the zoom ring 18 of the subtended angle adjusting ring 6 of light shield and video camera, turn zoom ring 18 just can be realized the function of servo-actuated.

Claims

1, a kind of light shield that is used for zoom lens, mainly by cover body, base is formed, it is characterized in that, cover body is by the overlapping successively closed shape that forms of some blades, all blades fuse with flexible material in root, be fixed between main base frame and the trim ring, trim ring and main base frame thread connection, in the outside of main base frame, have with it can only axial displacement the lifting circle, on each blade of cover body outer lower end, fixed-hinged support is arranged, respectively, link to each other, the subtended angle adjusting ring is axially fixed between cover plate and the main base frame with the hinged-support of relevant position on the lifting circle by connecting rod, the lifting circle relies on the screw thread of itself and subtended angle adjusting ring to pay, and realizes moving up and down.

2, a kind of light shield that is used for zoom lens according to claim 1 is characterized in that, cover body connects with base, adopts screw thread to pay.

3, a kind of light shield that is used for zoom lens according to claim 1 is characterized in that, cover body connects with base, is realized by the spring compression sliding plug, apart from the appropriate location that above-mentioned spring and sliding plug are installed one rotation shifting block is arranged on main base frame.

According to claim 1,2,3 described a kind of light shields that are used for the thing zoom lens, it is characterized in that 4, between the subtended angle adjusting ring of light shield and the zoom ring of video camera, having can be in the bindiny mechanism of axial stretching.