A kind of automatic focusing mechanism and camera
Technical field
The utility model is related to automatic control technology field, more particularly to a kind of automatic focusing mechanism and application have it is described from
The camera of dynamic focusing mechanism.
Background technology
LCD screen is generally entered with automatic optics inspection technology (Automatic Optic Inspection) to its quality
Row evaluation.The size of common LCD screen, and then resolution ratio on different screen and corresponding pixel are not yet
It is identical.During using automatic optics inspection technical optics detection LCD screen, to ensure Detection accuracy, it is desirable to tested
One pixel of the LCD screen of survey at least needs 9 pixels of corresponding detection camera, i.e. LCD screen imaging accounts for camera
The ratio of visual field is bigger, and accuracy of detection is also bigger, and Detection results are better.Due to the size and pixel number of liquid crystal display
Often correlation is measured, therefore, when detecting small size liquid crystal display, it is necessary to detect camera with detection faces apart from closely, that is, is needed
Will shorter object distance;When detecting Large-size LCD Screen, it is necessary to which the distance for detecting camera and detection faces is remote, that is, need longer object distance.
Traditional detection camera, often change a detected LCD screen and be required to adjust an object distance to meet detection essence
The requirement of degree.The industrial lens majority of traditional detection camera matching is tight shot, when the focal plane of tight shot falls in camera
Photosurface on when obtain optimal shooting effect, the focal plane referred to the focus of tight shot and perpendicular to the flat of primary optical axis
Face.After object distance is adjusted, the focal plane of the tight shot can no longer overlap with the photosurface of camera, and this will cause optical system
Defocus, image quality decrease, image blur are caused, directly affect follow-up image information extraction and processing work.
In order to meet the shooting demand under different object distances, tight shot needs external focusing adapter ring, by the mode of range estimation
Manual focusing is carried out, time-consuming for the operation, repeatability is small, while Adjustment precision is larger by personnel's subjective impact, can influence work
Industry produces and the efficiency of measurement.
Therefore, need badly a kind of focal plane that can automatically, fast and accurately adjust tight shot of exploitation fall it is photosensitive in camera
The focusing mechanism in face.
Utility model content
In order to overcome problem present in correlation technique, it is fast and accurately automatic that the utility model provides a kind of focusing
Focusing mechanism.To achieve the above object, the utility model employs following technical scheme:
A kind of automatic focusing mechanism, described device is applied on the tight shot 2 that is used cooperatively with camera 1, for automatic
The focal plane of adjustment tight shot 2 falls on the photosurface of camera 1, and described device includes supporting device, drive mechanism, position sense
Mechanism and controlling organization are answered,
The supporting device includes housing 3 and end cap 4, on the inwall of the housing 3, is offered along its circumference and housing
The annular groove 31 that 3 bottom end face is connected, the end cap 4 are annular disk, are removably mounted to the bottom of housing 3;
The drive mechanism includes motor 5 and driving gear component, and the driving gear component includes what is be meshed
Driving gear 6 and driven gear 7 and the screw shell 8 being arranged in inside driven gear 7,
The motor 5 is arranged on the outside of the housing 3, and the driving gear 6 is arranged on the output of motor 5
On axle, the output shaft rotating can be surrounded, relative place sets jagged, the driving gear to the housing 3 with driving gear 6
6 and driven gear 7 engaged by the breach,
The driven gear 7 is cylinder, and the external tooth 71 being meshed with driving gear 6 is provided with its outer wall, is set on inwall
There is the internal thread 72 coordinated with screw shell 8, the clamping of driven gear 7 is arranged in the annular groove 31 of housing 3 and is overlapped on
On the top surface of the end cap 4,
The screw shell 8 is to be fixedly mounted on the screw shell 8 with externally threaded cylinder, the tight shot 2
Cylinder interior,
The location sensitive mechanism includes spacer 9 and position sensor 10, and the spacer 9 is arranged on the thread bush
One end of cylinder 8, the position sensor 10 are arranged on the outer wall of the housing 3;
The controlling organization, for obtaining the image of the measured object in the visual field of tight shot 2, and according to described image
Judge the focal plane position of the tight shot 2, generation focusing is instructed and sent to the drive mechanism, so that the driving machine
Structure drives tight shot 2 to be moved along primary optical axis.
Optionally, the tight shot 2 is stairstepping cylinder, and being socketed with camera lens in its external stability fixes adapter ring 11, institute
Camera lens is stated to fix adapter ring 11 as cylinder and be fixedly connected with the inwall of screw shell 8.
Optionally, the line slide rail 12 of the threadingly axial direction of sleeve 8 is installed on the inwall of the housing 3,
The top of the screw shell 8 is provided with the support platform 81 extended radially outward, in the support platform 81
It is provided with neck,
The card of line slide rail 12 is set in the neck, and the screw shell 8 can be past along the line slide rail 12
Multiple motion, the top of the line slide rail 12, which is provided with, to be used to limit the limited block 121 that the screw shell 8 moves.
Optionally, the position sensor 10 is magnetic force induction device, and the spacer 9 is made of magnetic material.
Optionally, the supporting device also includes protective cover 13, and the cylinder of protective cover 13, end is fixedly mounted on end cap
4 side-wall outer side.
The utility model also provides a kind of camera, the camera 1 and the tight shot 2 for being provided with above-mentioned automatic focusing mechanism
It is used cooperatively, wherein, the camera 1 is connected by flange 14 with the housing 3 of described device.
Automatic focusing mechanism of the present utility model by the rotary motion of motor by being changed into tight shot and camera
Between linear motion, while coordinate with location sensitive mechanism and controlling organization, realize between tight shot and camera from
Dynamic focus process, focusing speed is fast, and accuracy rate is high, reduces cost of labor, also improves production efficiency.
Brief description of the drawings
In order to illustrate more clearly of the technical solution of the utility model, below by the required accompanying drawing used in embodiment
It is briefly described, it should be apparent that, for those of ordinary skills, do not paying the premise of creative labor
Under, other accompanying drawings can also be obtained according to these accompanying drawings.
Fig. 1 is camera overall structure diagram of the present utility model;
Fig. 2 is the structural representation of automatic focusing mechanism of the present utility model;
Fig. 3 is the transmission structures schematic diagram of automatic focusing mechanism of the present utility model;
Fig. 4 is the cross-sectional view of automatic focusing mechanism of the present utility model.
In figure:1- cameras, 2- tight shots, 3- housings, 31- annular grooves, 32- first through hole, 4- end caps, 5- driving electricity
Machine, 6- driving gears, 71- external tooths, 72- internal threads, 7- driven gears, 8- screw shells, 81- support platforms, 9- spacers,
10- position sensors, 11- camera lenses fixation adapter ring, 12- line slide rails, 121- limited blocks, the through holes of 122- second, 13- protective covers,
14- flanges.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the embodiment of the utility model is carried out
Clear, complete description.Obviously, described embodiment is only the utility model part of the embodiment, rather than whole
Embodiment.Based on the embodiment in the utility model, those of ordinary skill in the art are not under the premise of creative work is made
The every other embodiment obtained, belong to the scope of the utility model protection.
The utility model embodiment provides a kind of automatic focusing mechanism, and referring to Fig. 1 to Fig. 4, described device is applied to and phase
On the tight shot 2 that machine 1 is used cooperatively.The photosurface of the primary optical axis and camera 1 of the tight shot 2 is perpendicular, i.e., described fixed
The focal plane of zoom lens 2 and the photosurface of camera 1 are parallel to each other, by drive tight shot 2 with respect to camera 1 do closer or far from
Motion so that detect different object distances liquid crystal display when the tight shot 2 focal plane can fall in the photosensitive of camera 1
On face, reach clearly shooting effect, wherein, the camera 1 can be CCD camera.
Described device includes being used to protect and the supporting device of fixed tight shot 2, for adjust the tight shot 2 with
The drive mechanism of distance between camera 1, the location sensitive mechanism for determining the position of tight shot 2 and for sending focusing
The controlling organization of instruction.
Wherein, housing 3 and end cap 4 are included referring to Fig. 1 and Fig. 2, the supporting device, the housing 3 is cylinder, described
On the inwall of housing 3, the annular groove 31 being connected with the bottom end face of housing 3 is offered along its circumference.The end cap 4 is section
Class is annular disk, for example, the end cap 4 specifically may include along the platform being radially arranged of the housing 3 and in the platform
Axially arranged side wall of the lateral edges along the housing 3.The platform of the end cap 4, which such as is connected by screw at the mode, removably pacifies
It is connected mounted in the bottom of housing 3, and with annular groove 31.Certainly, the end cap 4 can also use other shapes, not do herein
Excessive limitation.
The supporting device can also include protective cover 13, and the protective cover 13 is cylinder, and end is fixedly mounted on described
The side-wall outer side of end cap 4.The protective cover 13 further can provide protection to tight shot 2.
The drive mechanism, including motor 5 and driving gear component, the driving gear component include driving gear
6th, the driven gear 7 being meshed with driving gear 6 and the screw shell 8 being arranged in inside driven gear 7.The drive mechanism energy
Enough linear motions that the rotary motion of motor is changed into tight shot 2.
The motor 5 is arranged on the outside of the housing 3, and the driving gear 6 is arranged on the output of motor 5
On axle, the output shaft rotating can be surrounded.Jagged, the driving gear 6 of the place's setting relative with driving gear of housing 3
It is meshed with driven gear 7 by the breach.
The driven gear 7 is the cylinder that can be rotated around central shaft, and its clamping is arranged on the annular groove 31 of the housing 3
In and be overlapped on the top surface of the end cap 4.Be provided with the outer wall of the driven gear 7 be meshed with driving gear 6 it is outer
Tooth 71, the internal thread 72 coordinated with screw shell 8 is provided with inwall.
The screw shell 8 is to be fixedly mounted on the screw shell 8 with externally threaded cylinder, the tight shot 2
Inside.Specifically, the tight shot 2 is stairstepping cylinder, being socketed with camera lens in its external stability fixes adapter ring 11, described
Camera lens fixes adapter ring 11 and is cylinder and is fixedly connected with the inwall of the screw shell 8.The camera lens fixes adapter ring 11 can basis
Different tight shot 2 selects different specifications, realizes that a variety of tight shots 2 in the installation of screw shell 8, add application
Popularity.
When the driving gear 6 rotates under the drive of motor 5,7 turns of the driven gear being meshed with driving gear 6
It is dynamic so that the screw shell 8 being meshed with internal thread 72 moves back and forth with respect to camera 1, and then drives and be arranged on the thread bush
Tight shot 2 in cylinder 8 moves back and forth along key light direction of principal axis, realizes the effect of focusing.
Wherein, the motor 5 can use servo planetary reducing motor, for example, using speed reducing ratio as 1:45 watch
It is 1 to take planetary reducing motor and gear ratio:2 driving and driven gear realizes the function of slowing down, while is 6mm's from pitch
Screw shell enters line translation, it is possible to achieve the control servo planetary reducing motor camera lens that often rotates a circle moves up and down 0.006mm, far
Much smaller than the requirement of the camera depth of field, it is possible to achieve clearly purpose of focusing.Certainly, it the foregoing is only a specific implementation
Example, can not do excessive restriction herein according to the suitable equipment of different application environmental selection and parameter in actual applications.
In addition, referring to Fig. 2 to Fig. 4, also it is installed with the inwall of the housing 3 at least one along the thread bush
The line slide rail 12 that 8 axial directions of cylinder are set, the screw shell 8 being capable of straight line cunnings described in the drive lower edge in motor 5
Rail 12 moves back and forth.
Specifically, offering first through hole 32 in the side wall of the housing 3, it is logical that second is offered on the line slide rail 12
Hole 122, the through hole 122 of first through hole 32 and second cooperate, and the mode such as are connected by screw and fix line slide rail 12
On the inwall of housing 3.The top of the screw shell 8 is provided with the support platform 81 extended radially outward, described
The first neck is provided with support platform 81, the card of line slide rail 12 is set in first neck and and thread bush
Certain gap be present between the external screw thread of cylinder 8, avoid influenceing the movement of screw shell 8.
Because the line slide rail 12 is integrally fixed on the inwall of housing 3, thus the screw shell 8 with driven tooth
Rotation will not be produced in the circumferential during the engaged transmission of wheel 7, but is moved back and forth only along line slide rail 12, and this can keep away
Exempt from focus process because the unstability that the rotating band of tight shot 2 comes, easy to operation.
Referring to Fig. 3 and Fig. 4, close to driven gear 7, top is provided with described for limiting for the bottom of the line slide rail 12
The limited block 121 for the extreme position that screw shell 8 moves in line slide rail 12.When the screw shell 8 moves to limited block 121
Stop motion during place, prevent the screw shell 8 from moving excessively and deviating from from line slide rail 12, influence the efficiency of focus process
And the degree of accuracy.
The location sensitive mechanism is used for the limit position of the initial position for determining tight shot 2 and tight shot motion
Put, it is for instance possible to use magnetic force induction device, including for characterizing the spacer 9 of the position of tight shot 2 and being positioned for sensing
The position sensor 10 of the position of piece 9, the spacer 9 are block structure made of magnetic material, and the position sensor 10 is
Magnetic force induction device.The second neck is provided with the support platform 81 of the screw shell 8, the insertion of spacer 9 is arranged on institute
State in the second neck.Outside the housing 3 corresponding with the position for two end points that the spacer 9 moves on line slide rail 12
Position sensor 10 is separately installed with wall, the position sensor 10 keeps synchronous positioning by sensing with tight shot 2
The position of piece 9, and then can determine the position of tight shot 2.
The location sensitive mechanism coordinates with the controlling organization to play a role, specifically, as shown in Figure 2, institute
It can be controlled by computer etc. to state controlling organization.Wherein, one is preset with before automatic focusing mechanism work to focus
The initial position of camera lens 2.When focus process starts, if tight shot 2 can not sent in initial position, the controlling organization
For the signal of one reply initial position to motor 5, the motor 5 drives the tight shot 2 to move, and passes through institute
Rheme puts induction mechanism and confirms whether tight shot 2 has reached initial position.
After tight shot 2 reaches default initial position, the controlling organization is obtained in the visual field of tight shot 2
The image of testee, and judge according to described image the focal plane position of the tight shot 2, and generate corresponding focusing and refer to
Order to the motor 5, the motor 5 rotates and drives tight shot 2 to be moved back and forth along key light direction of principal axis, until fixed
Image clearly in the visual field of zoom lens 2, and then focus process is completed.
Also include a kind of camera in the utility model, the camera 1 and be provided with above-mentioned automatic focusing mechanism focus mirror
First 2 are used cooperatively, wherein, the camera 1 is connected by flange 14 with the housing 3 of described device.The camera 1 is by focusing
Camera lens 2 is engaged, and the technique effect of auto-focusing can be realized in different production environments, is effectively improved production effect
Rate.
The rotary motion of motor can be changed into fixed by the drive mechanism in automatic focusing mechanism of the present utility model
The linear motion of zoom lens, whole focusing mechanism characteristics of compact layout can effectively save installing space.Meanwhile can be suitable by selecting
Motor and driving gear component, it is possible to achieve the distance that tight shot moves every time is in a very small scope
It is interior, much smaller than the depth of field requirement of camera, reach clearly focus effects.Meanwhile the utility model sends finger by controlling organization
Auto-focusing process is realized in order, can effectively improve efficiency, Adjustment precision is relatively stable, can effectively improve industrial production and survey
The efficiency of amount.
Those skilled in the art will readily occur to this practicality after considering specification and putting into practice utility model disclosed herein
New other embodiments.The utility model is intended to any modification, purposes or adaptations of the present utility model,
These modifications, purposes or adaptations follow general principle of the present utility model and undocumented including the utility model
Common knowledge or conventional techniques in the art.Description and embodiments are considered only as exemplary, and this practicality is new
The scope of type is only limited by appended claim.