CN101887166A - Ocular - Google Patents

Abstract

The invention relates to an ocular, comprising an aperture, a first lens, a second lens and a third lens which are coaxially and successively arranged from the observing side of human eyes to the display device side along the direction of an optic axis, and the relation among materials, the focuses and positions of the first lens, the second first lens and the third lens meet a certain relation, thus an image displayed on a displayer is imaged in human eyes at the aperture after being amplified by the ocular. The ocular of the invention has the advantages of large bore diameter, large field of view, short focus, low aberration and the like, is suitable for the head-wearing displayer and similar devices, can be made of optic plastics, and has light weight and low cost.

Description

Eyepiece

Technical field

The present invention relates to optical technical field, more particularly, relate to a kind of eyepiece that is applicable to head-mounted display or similar device.

Background technology

Head-mounted display (or claiming Helmet Mounted Display, video eyeglasses) still all has huge using value and market in fields such as military affairs, industry, medical treatment at multimedia recreation.To the requirement of head-mounted display be that comfortable wearing, compact conformation volume are little, high imaging quality and big as far as possible visual field.

Head-mounted display mainly is made up of three parts: display unit, optical system, connect the above two physical construction.Optical system has determined image quality, visual field size, the volume size of head-mounted display, and promptly optical system is the core of head-mounted display, and its performance parameter has determined product total system parameter.

Use for head-mounted display, require optical system to try one's best big visual field to guarantee to have enough feeling of immersion; Require the bigger emergent pupil size of optical system, can not lose image in the Oculomotor while with the people who guarantees different pupil distances; Require the optical system little focal length of trying one's best, to guarantee system compact type and enough enlargement ratios.And visual field, emergent pupil size, these three parameters of focal length are mutual restriction for optical system.At present, traditional goggle structure with coaxial spherical lens group can't satisfy the requirement of high picture element, big visual field and small size, and optical system compactedness and optical system imaging quality require to exist certain contradiction.On the other hand, coaxial eyepiece optical system has processing technology maturation, with low cost, steady performance.Overcome the shortcoming of centered optical system, bringing into play its advantage is the inherent requirement of good available optical system.

Summary of the invention

The technical problem to be solved in the present invention is, can't satisfy the defective of the requirement of high picture element, big visual field and small size at the eyepiece of existing head-mounted display, a kind of eyepiece that is applicable to head-mounted display or similar device is provided, and its distance of exit pupil is long, field angle is big and volume is less relatively.

The technical solution adopted for the present invention to solve the technical problems is: construct a kind of eyepiece, comprise three all-plastic lens, as Fang Yuanxin; Described eyepiece from eye-observation one side to display device one side, along coaxial diaphragm, first lens, second lens and the 3rd lens of being arranged in order of coaxial direction;

Wherein, the focal length of described first lens is f1, and the focal length of second lens is f2, the focal length of the 3rd lens is f3, and the total focal length of system is fw, and diaphragm is df to the centre distance of first lens, the 3rd lens are db to the centre distance of the display chip of display device, and satisfy following relational expression:

1)0.6＜f1/fw＜0.85，

2)0.4＜|f2/fw|＜0.6，

3)0.5＜f3/fw＜0.75，

4)0.78＜df/fw＜0.82，

5)0.28＜db/fw＜0.45；

And the material of described first lens, second lens and the 3rd lens satisfies following the requirement:

Nd1＞1.48, Nd3＞1.48, Nd1, Nd3 represent first lens, the 3rd lens refractive index at the d line respectively;

Vd1＞56, Vd3＞56, Vd1, Vd3 represent first lens, the 3rd lens Abbe number at the d line respectively;

Nd2＞1.55, Vd2＜30, Nd2, Vd2 represent refractive index and the Abbe number of second lens at the d line respectively.

In preferred embodiments more of the present invention, described first lens and the 3rd lens are positive lens, and second lens are negative lens.Further in the preferred embodiment, described first lens are biconvex lens in the present invention, and described the 3rd lens are meniscus shaped lens, and two curvature of curved surface radiuses of the 3rd lens be on the occasion of.

In preferred embodiments more of the present invention, the focal length of described first lens, second lens and the 3rd lens further satisfies following relational expression, to obtain better imaging effect:

6)0.7＜f1/fw＜0.8；

7)0.45＜|f2/fw|＜0.55；

8)0.6＜f3/fw＜0.73。

In preferred embodiments more of the present invention, described first lens, second lens and the 3rd lens are optical plastic.For example, described first lens and the 3rd lens can adopt polymethylmethacrylate (PolymethylMethacrylate PMMA) makes, i.e. Nd1=Nd3=1.492, Vd1=Vd3=57.3274.Second lens can adopt polycarbonate, and (Polycarbonate PC) makes, i.e. Nd2=1.586, Vd2=29.9309.Lens among the present invention are not limited only to above-mentioned two kinds of materials, can also select for use other to meet the optical plastic of refractive index and Abbe number scope.

In preferred embodiments more of the present invention, having an optical surface in described first lens, second lens and the 3rd lens at least is axisymmetric aspheric surface, with the corrective system aberration, as the curvature of field and distortion.Further among some embodiment, the optical surface of described first lens, second lens and the 3rd lens is all axisymmetric aspheric surface in the present invention, thus corrective system aberration better.Preferably, described aspheric expression formula is:

$z=\frac{{\mathrm{<figure-callout\; id="2"\; label="cr"\; filenames="HDA0000023347790000011.png,HDA0000023347790000023.png"\; state="\{\{state\}\}">cr</figure-callout>}}^2}{1+\sqrt{1-(1+k)c^2{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HDA0000023347790000011.png,HDA0000023347790000023.png"\; state="\{\{state\}\}">r</figure-callout>}}^2}}+{\mathrm{\&alpha;}}_2{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HDA0000023347790000011.png,HDA0000023347790000023.png"\; state="\{\{state\}\}">r</figure-callout>}}^2+{\mathrm{\&alpha;}}_4{\mathrm{<figure-callout\; id="4"\; label="r"\; filenames="HDA0000023347790000023.png"\; state="\{\{state\}\}">r</figure-callout>}}^4{+\mathrm{\&alpha;}}_6{\mathrm{<figure-callout\; id="6"\; label="r"\; filenames="HDA0000023347790000011.png,HDA0000023347790000012.png"\; state="\{\{state\}\}">r</figure-callout>}}^6+......;$

Wherein, z is the rise of optical surface, and c is a curvature, and k is an asphericity coefficient, α _2,4,6... be each rank coefficient.

Implement eyepiece of the present invention, have following beneficial effect: eyepiece of the present invention adopts three lens with different qualities, the image that display device is shown amplifies by the optical system that this eyepiece constitutes, and through being positioned at the eyes imaging at diaphragm place, this eyepiece exit pupil diameter is greater than general eyepiece, it is as Fang Yuanxin, illumination evenly, compact conformation, big visual field, low distortion.In addition, the present invention can adopt aspheric design, thereby utilizes optical aspherical surface to the optical system anaberration, has guaranteed big distance of exit pupil, big field angle, low distortion.Simultaneously, the eyeglass that the present invention also adopts optical plastic to make, for glass mirror, its light weight, cost are low, can realize the aspheric surface of the higher order polynomial that glass is difficult to realize.

Description of drawings

The invention will be further described below in conjunction with drawings and Examples, in the accompanying drawing:

Fig. 1 shows the optical system diagram according to the eyepiece of first embodiment of the invention;

The optical system that Fig. 2 shows according to the eyepiece of first embodiment of the invention passes letter figure;

Fig. 3 (a) and Fig. 3 (b) show the curvature of field and the distortion curve according to the eyepiece of first embodiment of the invention respectively;

Fig. 4 shows the optical system diagram according to the eyepiece of second embodiment of the invention;

The optical system that Fig. 5 shows according to the eyepiece of second embodiment of the invention passes letter figure;

Fig. 6 (a) and Fig. 6 (b) show the curvature of field and the distortion curve according to the eyepiece of second embodiment of the invention respectively;

Fig. 7 shows the optical system diagram according to the eyepiece of third embodiment of the invention;

The optical system that Fig. 8 shows according to the eyepiece of third embodiment of the invention passes letter figure;

Fig. 9 (a) and Fig. 9 (b) show the curvature of field and the distortion curve according to the eyepiece of third embodiment of the invention respectively.

Embodiment

In order to make purpose of the present invention, technical scheme and advantage clearer,, the present invention is further elaborated below in conjunction with drawings and Examples.

See also Fig. 1, be optical system diagram according to the eyepiece of first embodiment of the invention.As shown in Figure 1, to display device I side (from left to right), be followed successively by diaphragm E, the first lens L1, the second lens L2, the 3rd lens L3 and display device I from the eye-observation side.In the present embodiment, the first lens L1 and the 3rd lens are positive lens, and second lens are that negative lens is with the corrective system aberration.And the first lens L1, the second lens L2, the 3rd lens L3 all adopt aspheric surface to comprise the curvature of field and distortion with the corrective system aberration.At this, be 1 with diaphragm E surface sequence number, and the like, display device I surface is 8.

The described first embodiment eyepiece design data is as shown in table 1 below:

Table 1

Each surperficial aspheric surface parameter is as follows among first embodiment:

Surface 2 (Surface 2) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：6.1412944e-005

Coeff?on?r?6：2.5580088e-006

Coeff?on?r?8：-1.1230122e-007

Coeffon?r?10：8.9015252e-010

Surface 3 (Surface 3) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：-3.309314e-005

Coeff?on?r?6：9.3557479e-007

Coeff?on?r?8：-9.0216008e-008

Coeff?on?r?10：8.8576475e-010

Surface 4 (Surface 4) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：-9.6376876e-005

Coeff?on?r?6：2.6558718e-006

Coeff?on?r?8：-1.7473741e-007

Coeff?on?r?10：1.545018e-009

Surface 5 (Surface 5) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：4.4542079e-005

Coeff?on?r?6：1.2197471e-005

Coeff?on?r?8：-1.473328e-007

Coeff?on?r?10：-3.1703855e-009

Surface 6 (Surface 6) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：-3.8892206e-006

Coeff?on?r?6：8.4908171e-006

Coeff?on?r?8：-4.6741251e-008

Coeff?on?r?10：3.9082855e-009

Surface 7 (Surface 7) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：-9.6742694e-006

Coeff?on?r?6：2.5950192e-006

Coeff?on?r?8：-3.1095373e-008

Coeff?on?r?10：1.1111381e-008

See also Fig. 2, show optical system biography letter figure according to the eyepiece of first embodiment of the invention; Fig. 3 (a) and Fig. 3 (b) show the curvature of field and the distortion curve according to the eyepiece of first embodiment of the invention respectively.As shown in the figure, characterize out the image quality height of the optical system of present embodiment, and distance of exit pupil is big, field angle big and distort low.

See also Fig. 4, be optical system diagram according to the eyepiece of second embodiment of the invention.As shown in Figure 4, to display device I side (from left to right), be followed successively by diaphragm E, the first lens L1, the second lens L2, the 3rd lens L3 and display device I from the eye-observation side.In the present embodiment, the first lens L1 and the 3rd lens are positive lens, and second lens are that negative lens is with the corrective system aberration.And the first lens L1, the second lens L2, the 3rd lens L3 all adopt aspheric surface to comprise the curvature of field and distortion with the corrective system aberration.At this, be 1 with diaphragm E surface sequence number, and the like, display device I surface is 8.

The described second embodiment eyepiece design data is as shown in table 2 below:

Table 2

Each surperficial aspheric surface parameter is as follows among second embodiment:

Surface 2 (Surface 2) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：0.0001745316

Coeff?on?r?6：-5.2971102e-006

Coeff?on?r?8：-2.1845734e-008

Coeff?on?r?10：-6.5191306e-011

Surface 3 (Surface 3) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：4.9511029e-005

Coeff?on?r?6：-9.2132981e-006

Coeff?on?r?8：1.3727281e-007

Coeffon?r?10：-1.3061152e-009

Surface 4 (Surface 4) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：-0.00012965859

Coeff?on?r?6：7.9030145e-006

Coeff?on?r?8：-1.0006347e-007

Coeff?on?r?10：6.9167038e-010

Surface 5 (Surface 5) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：0.00028663084

Coeff?on?r?6：6.519007e-006

Coeff?on?r?8：-5.9855651e-009

Coeff?on?r?10：-9.1306036e-009

Surface 6 (Surface 6) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：0.00090713675

Coeff?on?r?6：2.2296566e-006

Coeff?on?r?8：-1.8815219e-007

Coeff?on?r?10：1.4724701e-008

Surface 7 (Surface 7) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：0.00059319234

Coeff?on?r?6：4.0858718e-006

Coeff?on?r?8：1.4863469e-006

Coeff?on?r?10：-4.0050924e-009

See also Fig. 5, show optical system biography letter figure according to the eyepiece of second embodiment of the invention; Fig. 6 (a) and Fig. 6 (b) show the curvature of field and the distortion curve according to the eyepiece of second embodiment of the invention respectively.As shown in the figure, characterize out the image quality height of the optical system of present embodiment, and distance of exit pupil is big, field angle big and distort low.

See also Fig. 7, be optical system diagram according to the eyepiece of third embodiment of the invention.As shown in Figure 7, to display device I side (from left to right), be followed successively by diaphragm E, the first lens L1, the second lens L2, the 3rd lens L3 and display device I from the eye-observation side.In the present embodiment, the first lens L1 and the 3rd lens are positive lens, and second lens are that negative lens is with the corrective system aberration.And the first lens L1, the second lens L2, the 3rd lens L3 all adopt aspheric surface to comprise the curvature of field and distortion with the corrective system aberration.At this, be 1 with diaphragm E surface sequence number, and the like, display device I surface is 8.

Described the 3rd embodiment eyepiece design data is as shown in table 3 below:

Table 3

Each surperficial aspheric surface parameter is as follows among the 3rd embodiment:

Surface 2 (Surface 2) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：1.8244971e-005

Coeff?on?r?6：3.1538296e-007

Coeff?on?r?8：-9.6275999e-009

Coeff?on?r?10：4.0616455e-011

Surface 3 (Surface 3) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：-9.9131785e-006

Coeff?on?r?6：1.1435686e-007

Coeff?on?r?8：-8.2047549e-009

Coeff?on?r?10：4.0336685e-011

Surface 4 (Surface 4) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：-3.6208325e-005

Coeff?on?r?6：4.3831507e-007

Coeff?on?r?8：-1.3845781e-008

Coeff?on?r?10：6.000235e-011

Surface 5 (Surface 5) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：1.0301347e-005

Coeff?on?r?6：1.8357947e-006

Coeff?on?r?8：-1.6625861e-008

Coeff?on?r?10：-1.2036801e-010

Aperture (Aperture): the aperture (F1oating Aperture) of floating

Maximum curvature radius (Maximum Radius): 8.235294

Surface 6 (Surface 6) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：-2.1447272e-006

Coeff?on?r?6：1.4611758e-006

Coeff?on?r?8：-3.915728e-009

Coeff?on?r?10：1.207144e-010

Surface 7 (Surface 7) type: EVENASPH

Coeff?on?r?2：????????????0

Coeff?on?r?4：6.3635648e-006

Coeff?on?r?6：4.0540057e-007

Coeff?on?r?8：-4.0568124e-009

Coeff?on?r?10：4.3656109e-010

See also Fig. 8, show optical system biography letter figure according to the eyepiece of third embodiment of the invention; Fig. 9 (a) and Fig. 9 (b) show the curvature of field and the distortion curve according to the eyepiece of third embodiment of the invention respectively.As shown in the figure, characterize out the image quality height of the optical system of present embodiment, and distance of exit pupil is big, field angle big and distort low.

From every data of foregoing invention embodiment, can obtain the embodiment of the invention and satisfy the aforementioned requirement that concerns, the result is as shown in the table:

	??f1/fw	??|f2/fw|	??f3/fw	??df/fw	??db/fw
						Embodiment 1	??0.7469	??0.503	??0.686	??0.786	??0.391
Embodiment 2	??0.7072	??0.501	??0.734	??0.786	??0.359
						Embodiment 3	??0.7152	??0.490	??0.69435	??0.7751	??0.4194

The present invention is described according to specific embodiment, but it will be understood by those skilled in the art that when not breaking away from the scope of the invention, can carry out various variations and be equal to replacement.In addition, for adapting to the specific occasion or the material of the technology of the present invention, can carry out many modifications and not break away from its protection domain the present invention.Therefore, the present invention is not limited to specific embodiment disclosed herein, and comprises that all drop into the embodiment of claim protection domain.

Claims (10)

1. an eyepiece is characterized in that, comprise from the eye-observation side to the display device side along optical axis direction the coaxial diaphragm that is arranged in order, first lens, second lens and the 3rd lens;

The focal length of described first lens is f1, and the focal length of second lens is f2, and the focal length of the 3rd lens is f3, the total focal length of system is fw, diaphragm is df to the centre distance of first lens, and the 3rd lens are db to the centre distance of the display chip of display device, and satisfies following relational expression:

1)0.6＜f1/fw＜0.85，

2)0.4＜|f2/fw|＜0.6，

3)0.5＜f3/fw＜0.75，

4)0.78＜df/fw＜0.82，

5)0.28＜db/fw＜0.45；

And the material of described first lens, second lens and the 3rd lens satisfies following the requirement:

Nd1＞1.48, Nd3＞1.48, Nd1, Nd3 represent first lens, the 3rd lens refractive index at the d line respectively;

Vd1＞56, Vd3＞56, Vd1, Vd3 represent first lens, the 3rd lens Abbe number at the d line respectively;

Nd2＞1.55, Vd2＜30, Nd2, Vd2 represent refractive index and the Abbe number of second lens at the d line respectively.

2. eyepiece according to claim 1 is characterized in that, described first lens and the 3rd lens are positive lens, and second lens are negative lens.

3. eyepiece according to claim 2 is characterized in that, described first lens are biconvex lens, and described the 3rd lens are meniscus shaped lens, and two curvature of curved surface radiuses of the 3rd lens be on the occasion of.

4. eyepiece according to claim 1 is characterized in that, the focal length of described first lens, second lens and the 3rd lens further satisfies following relational expression:

6)0.7＜f1/fw＜0.8；

7)0.45＜|f2/fw|＜0.55；

8)0.6＜f3/fw＜0.73。

5. eyepiece according to claim 1 is characterized in that, described first lens, second lens and the 3rd lens are optical plastic.

6. eyepiece according to claim 5 is characterized in that, described first lens and the 3rd lens adopt polymethylmethacrylate to make.

7. eyepiece according to claim 6 is characterized in that, described second lens adopt polycarbonate to make.

8. according to any described eyepiece in the claim 1 to 7, it is characterized in that having an optical surface in described first lens, second lens and the 3rd lens at least is axisymmetric aspheric surface.

9. eyepiece according to claim 9 is characterized in that, the optical surface of described first lens, second lens and the 3rd lens is all axisymmetric aspheric surface.

10. eyepiece according to claim 9 is characterized in that, described aspheric expression formula is:

$z=\frac{{\mathrm{cr}}^2}{1+\sqrt{1-(1+k)c^2{r}^2}}+{\mathrm{\&alpha;}}_2{r}^2+{\mathrm{\&alpha;}}_4{r}^4{+\mathrm{\&alpha;}}_6{r}^6+......;$

Wherein, z is the rise of optical surface, and c is a curvature, and k is an asphericity coefficient, α _2,4,6... be each rank coefficient.

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