CN201051174Y - Continuous zooming medical TV transfer lens - Google Patents

Abstract

A medical television switching lens capable of continuous magnification relates to optical lens devices, which is applicable to chemical fibre opic endoscope, gravity lens, microscope, telescope and the like which need to be connected with television picture pick-up devices. The utility model is characterized in that an entrance pupil and a retrofocus structure which is capable of continuous magnification and of which the emergent pupil tends to be axifugal are moved forward, the utility model is composed of two sealed glasses and seven lenses sequentially of a convex-concave negative lens, a convex-concave positive lens, a biconvex positive and negative lens, a convex-concave negative lens, a convex-concave positive lens, a biconcave negative lens and a biconvex negative lens, the third one and the fourth one compose a bind group, the first one and the second one compose a front group of lens with a combined focal length f' <> (front), lenses from the third one to the seventh one compose a rear group with a combined focal length f' <> (rear). The requirements are that -1.9< f' <.> (front)/f' <> (rear) < -1.8, 0.95< f' <> (front)/ f' <> (short) < 1.2, 0.005 < d <> (7) +d <> (8)/ f' <> (short) < 0.78, d <> (8) +1' = C, 1.57 < n <> (1) <1.60, 51< v <> (1) < 55, 1.69 < n <> (5)< 1.77, 50 < v <> (5) <56, 1.73 < n <> (7)< 1.78, 34 < v <> (7) < 38. The designed zoom value covers fixed focal length, and convenient operation and wider application are achieved.

Description

Zoom medical television switching mirror

Technical field:

The utility model relates to optical camera lens device.It is the relay optical camera lens that connects in observing system and the telephotography device.Be applicable to that fibre opic endoscope, gravity die mirror, eyepiece emergent pupil need install the switching device of TV or computer screen demonstration additional apart from long microscope and telescope etc.

Background technology:

The most fixed lens that adopt of existing medical television switching mirror in order to obtain the view image of suitable size, need the camera lens of multiple different focal to mate, and are difficult to displacement in the clinical use.In recent years, state is extrapolated can to see through the interval of adjusting optical element in the camera lens, realizes the focal length variations (claiming many focuses form abroad) of the discontinuous in the certain limit, and this camera lens has made things convenient for Medical Devices producer to adjust suitable focal length.But, medical treatment clinically the operator want to see the television image that amplifies or dwindle, group regulating ring and back group regulating ring are realized before can only adjusting respectively, need so repeatedly to adjust just can finish, and use not only inconvenience, also usually can lose view image.

In addition, the design of existing medical television switching mirror rear cut-off distance is short partially, and being difficult to be applicable to needs to adopt the high-resolution medical television observing system that colour splitting prism is arranged.

Summary of the invention:

The purpose of this utility model is to overcome above-mentioned defective, provide the back work distance of being convenient to adjustment of Medical Devices producer and medical clinical use to be tending towards " heart far away ", the medical television switching mirror of energy zoom (about zoom ratio 1.7) from length, entrance pupil reach, emergent pupil.

Scheme of the present utility model is: the utility model device of invention is made up of the sealing parallel plate glass of seven spherical lenses and two uniform thickness.The optical material of seven spherical lenses is in proper order: BaF₃, ZF₇, ZK₉, ZF₅, LaK₇, ZF₁₁, LaF₄Two parallel flat seal glass all adopt K₉Optical material.The profile of seven spherical lenses is successively: convex-concave negative lens, convex-concave positive lens, biconvex positive lens, concavo-convex negative lens, convex-concave positive lens, double-concave negative lens and biconvex positive lens.Wherein the 3rd lens and the 4th lens constitute the gummed group.First lens and second lens constitute preceding group of camera lens, and its complex focus is with f '_BeforeExpression; The 3rd to the 7th back group of constituting camera lens, f '_AfterRepresent its complex focus.The fixed light hurdle is located on the concave surface of second lens, makes on its size and the greatest axis of this face the light beam clear aperture the same.Preceding group and back group move by cam curve slot separately.During design, preceding group that makes camera lens is the compensation group of zoom lens, and it is by specific non-linear cam curve displacement; Back group of camera lens is that the change of zoom lens is doubly organized, and makes it by linear cam path displacement.By preceding group and the continuous variation of variation realization lens focus continuously one to one of back group spacing distance.

Two seal glass split the front and back of camera lens, and make them become the about 8 ° of angle lappings of reverse direction tiltedly (to eliminate the veiling glare that intraoral illumination may cause) with optical axis

The condition that optical devices must satisfy is as follows: (carrying out normalization by short burnt focal length value)

-1.9＜f '_Before/ f '_Short＜-1.8 ... (1)

0.95＜f '_After/ f '_Short＜1.2 ... (2)

0.005＜(d₇+ d₈)/f '_Short＜0.78 ... (3)

d₈+l′＝C ……………………………(4)

1.57＜n₁＜1.60，51＜ν₁＜55 ……………………(5)

1.69＜n₅＜1.77，50＜ν₅＜56 ……………………(6)

1.73＜n₇＜1.78，34＜ν₇＜38 ……………………(7)

Advantage of the present utility model is: adopted the zoom structure, make the operator only need rotate single regulating ring and just can be transferred to required value to focal length, and the image of observed thing has been clear all the time on display screen.The operator also can be earlier with big short focal length " search " target in visual field, and rotating adjustment ring amplifies (being transferred to the long end of focal length) continuously, to see the details of being inspected thing clearly.The minimum and maximum value of focal length of design has contained the scope in present medical fixed focal length switching border.Adopt the retrofocus type structure, elongated the rear cut-off distance of optical lens, meanwhile selected suitable f '_After, make the emergent pupil of camera lens be tending towards the heart far away, the quality that is beneficial to install the camera system of band colour splitting prism additional and improves color image.

The forward position of group before the light hurdle of novel switching mirror is arranged on so that the entrance pupil reach of switching mirror, makes it to overlap with the emergent pupil of preposition optical system such as endoscope, does not cut with the assurance visual field.

Description of drawings:

Fig. 1 is the optical schematic diagram that general fibre opic endoscope and telephotography device are transferred.A passes as light transmitting fiber among the figure, and B is the imaging fiber face, and C is the endoscope eyepiece, and D is that the emergent pupil of eyepiece also is the entrance pupil of switching mirror E, and F is CCD or CMOS picture pick-up device.

Fig. 2 adopts the optical schematic diagram of scheme for the utility model switching mirror.A passes as light transmitting fiber, and B is the imaging fiber face, and C is the endoscope eyepiece, and D is preceding group (negative lens), and E is the actual light hurdle, and E ' is that the emergent pupil of eyepiece also is the entrance pupil of switching mirror, and F is a back group (positive lens), and G is CCD or CMOS picture pick-up device.

Fig. 3 is the optical texture synoptic diagram of the utility model switching mirror.R is the radius-of-curvature of sphere among the figure, and d is the thickness of lens or the airspace between lens, and l ' is picture side's intercept of camera lens.

Fig. 4 be this example in f '=1, during entrance pupil diameter ψ=0.311,2 ω=25.04 °, the MTF curve map of different visual fields (on 1 ω, 0.707 ω, 0.5 ω, the axle).Horizontal ordinate unit is: line is right/and mm.

Fig. 5 be this example in f '=1.4, during entrance pupil diameter ψ=0.311,2 ω=18.2 °, the MTF curve map of different visual fields (on 1 ω, 0.707 ω, 0.5 ω, the axle).Horizontal ordinate unit is: line is right/and mm.

Fig. 6 be this example in f '=1.66, during entrance pupil diameter ψ=0.311,2 ω=15.8 °, the MTF curve map of different visual fields (on 1 ω, 0.707 ω, 0.5 ω, the axle).Horizontal ordinate unit is: line is right/and mm.

Fig. 7 is the structural representation of the utility model switching mirror.

Embodiment:

Embodiment: the utility model optical devices of invention are made up of the sealing parallel plate glass of seven spherical lenses and two uniform thickness.The optical material of seven spherical lenses is in proper order: BaF₃, ZF₇, ZK₉, ZF₅, LaK₇, ZF₁₁, LaF₄The profile of seven spherical lenses is successively: first (2) convex-concave negative lens, second (3) convex-concave positive lens, the 3rd (4) biconvex positive lens, the 4th (5) concavo-convex negative lens, the 5th (6) convex-concave positive lens, the 6th (7) double-concave negative lens and the 7th (8) biconvex positive lens.Wherein the 3rd (4) and the 4th (5) lens are formed the gummed group, and the parallel plane (9) of parallel plane of camera lens front (1) and camera lens back is the seal glass of camera lens.First (2) and second (3) constitute preceding group of the utility model camera lens, and its complex focus is with f '_BeforeExpression; The 3rd (4) to the 7th (8) constitute back group of camera lens, with f '_AfterRepresent its complex focus.The actual light hurdle of camera lens fixedly is located on the concave surface of second lens, and its size both had been the maximum transmission bore that the axle of this face is gone up light beam.Utility model of the present invention is that to make preceding group of camera lens be the compensation group of zoom lens, and it is by specific non-linear cam curve motion; Back group of camera lens is that the change of zoom lens is doubly organized, and makes it by linear cam groove telemechanical, changes continuously one to one by front and back group spacing distance, realizes the continuous variation of lens focus.During Design of Mechanical Structure, move by their edge cam paths separately by a regulating ring.Realize the purpose of continuous vari-focus.

The condition that optical devices must satisfy is as follows:

-1.9＜f '_Before/ f '_{Short burnt}＜-1.8 ... (1)

0.95＜f '_After/ f '_{Short burnt}＜1.2 ... (2)

0.005＜(d₇+ d₈)/f '_{Short burnt}＜0.78 ... (3)

d₈+ l '=C (field planting) ... (4)

1.57＜n₁＜1.60，51＜ν₁＜55 ………………………(5)

1.69＜n₅＜1.77，50＜ν₅＜56 ………………………(6)

1.73＜n₇＜1.78，34＜ν₇＜38 ………………………(7)

Setting the above-mentioned purpose that must satisfy condition is:

Condition 1: the purpose of setting is before and after guaranteeing under the little situation of group amount of movement, zoom ratio reach 1.7 left and right sides required and guarantee with back group combination after, the rear cut-off distance greater than switching mirror minimum focus value can be arranged.

The purpose thatcondition 2 is set is when making system that long rear cut-off distance be arranged, can accomplish that the optics length overall shortens (miniaturization), and makes emergent pupil image distance that the actual light hurdle becomes through its from being tending towards " heart far away ".

The purpose thatcondition 3 is set is to guarantee that preceding group of camera lens and back group are displaced to longly can not collide when burnt, limits the optics length overall simultaneously and is moving on to short length when burnt.

The purpose thatcondition 4 is set is when having only two unitized constructions to carry out zoom, guarantees the necessary condition of its imaging surface unanimity in the zoom process.

The purpose thatcondition 5 is set is effective correcting chromatic aberration.

The purpose thatcondition 6 andcondition 7 set is because the drift angle of going up beam angle through this axle of two is bigger, goes up for reducing the axle that is caused by them that the senior amount of spherical aberration sets.

Principal character of the present utility model is: according to the actual needs of medical clinical observation and easy to operate, this case has proposed to adopt the novel switching mirror structure of continuous vari-focus, make the operator can be transferred to required focal length easily, image keeps clear in the adjustment process, can realize " target " being searched for the short focal length of big visual field, can amplify " target " with long-focus again, see the details of " target " clearly.Owing to adopt anti-long distance version, elongated the rear cut-off distance of system, can satisfy the needs that behind the switching mirror, install colour splitting prism additional.Because the entrance pupil of novel switching mirror reach, make this scheme not only can be used for the long optical system of eyepiece emergent pupils such as fibre opic endoscope, gravity die mirror, also can be used for having the microscope and the telescope that grow interpupillary distance, guarantee that novel switching mirror is connected the phenomenon that the visual field cutting can not occur with them.

Table 1 is an example of the present utility model:

E.F.L=1～1.655, ψ_{Entrance pupil}(entrance pupil diameter)=0.311,2 ω=25.04～15.8, and colour killing spectral line d (F, C), l_Thing(object distance) ∞

Table 1: each eyeglass data d₈+ l '=1.260405

Sequence number	R (radius) (mm)	D (thickness at interval) (mm)	Nd (refractive index)	ν d (Abbe number)	Supplemental instruction
						1	∞	0.0555245	1.51637	64.1	K9(cover glass)
2	∞	0.1665734
						3	4.934237	0.0416434	1.579594	53.9	BaF3
4	0.592835	0.178789
						5	0.660741	0.0832867	1.806347	25.4	ZF7
6	0.840974	0.0188783			The light field is put
						7	∞	d7			(the compensation group at interval)
8	∞	d8			(becoming doubly group interval)
						9	0.694611	0.122154	1.620401	60.3	ZK9
10	-1.780114	0.0416434	1.740024	28.2	ZF5
						11	-67.99526	0.00555245
12	0.6088924	0.111049	1.712996	53.9	LaK7
						13	2.115482	0.0749580
14	-1.665623	0.0444196	1.698949	30.1	ZF11
						15	0.4664055	0.0444196
16	6.122683	0.144364	1.749505	35.0	LaF4
						17	-0.8495243	0.138811
18	∞	0.0555245	1.51637		K9(cover glass)
						19	∞	1′
20	∞				Image planes

Table 2: the zoom cam data table (normalized value) of main focal length point

Focal length (f)	d7	D8		Focal length (f ')	d7	d8
							1	0.397889	0.354444		1.3912	0.0792778	0.1436111
1.0573	0.327222	0.323889		1.4478	0.0568333	0.113056
							1.1141	0.266778	0.293333		1.4986	0.0401667	0.0855556
1.1654	0.219778	0.265833		1.5551	0.0249444	0.0550000
							1.2219	0.175444	0.235278		1.6115	0.0130556	0.0244444
1.2784	0.137778	0.204722		1.6563	0.00583333	0
							1.3349	0.105889	0.174167

D in the table₈Be by d_{8 (n+1)}=d_{8 (n)}+ 0.0030556 successively decreases.

Table 3: the third-order aberration coefficients (normalization) when long Jiao, middle Jiao, short Jiao.

	F '=1 (short burnt)	F '=1.39 (middle Jiao)	F '=(1.66 is long burnt)
				∑S1	0.00098	0.00030	0.00010
∑S2	0.00097	0.00013	0
				∑S3	0.00085	0.00002	-0.00004
∑S4	0.00008	0.00004	0.00003
				∑S5	0.001320	0	-0.00008
∑C1	-0.00007	-0.00004	-0.00003
				∑C2	-0.00007	-0.00002	-0.00001

Claims (1)

1. the utility model continuous vari-focus medical television switching mirror; it is characterized in that adopting the zoom structure to substitute the focal length discontinuous and change many focus structures; it comprises that seven lens are followed successively by first (2) convex-concave negative lens; second (3) convex-concave positive lens; the 3rd positive and negative mirror of (4) biconvex; the 4th (5) concavo-convex negative lens; the 5th convex-concave positive lens; the 6th (7) double-concave negative lens, the 7th (8) biconvex positive lens, the 3rd (4) and the 4th formation gummed group; two parallel flats (1; 9) be seal protection glass; the light hurdle is located on the concave surface of second (3) lens, and first (2) and second (3) constitute preceding group of lens, and its complex focus is with f '_BeforeExpression, the 3rd (4) to the 7th (8) constitute back group of camera lens, with f '_AfterRepresent its complex focus, the condition that optical devices must satisfy is as follows:

-1.9＜f '_Before/ f '_After＜-1.8 ... (1)

0.95＜f '_After/ f '_Short＜1.2 ... (2)

0.005＜d₇+ d₈/ f '_Short＜0.78 .... (3)

d₈+l′＝C …………………………(4)

1.57＜n₁＜1.60 51＜ν₁＜55 ………(5)

1.69＜n₅＜1.77 50＜ν₅＜56 ………(6)

1.73＜n₇＜1.78 34＜ν₇＜38 ………(7)。

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