CN101609208B - eyepiece - Google Patents

Abstract

The invention relates to an eyepiece, in particular to an eyepiece used in a head-mounted display, belonging to the field of optical technique. The eyepiece is formed by six pieces of lenses, and a lens screen, the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are sequentially arranged from the observing side of human eyes and the display device side along the direction of an optic axis in a coaxial way; the exit pupil diameter of the eyepiece is larger than that of the common eyepiece, the eye relief is long, the angle of view field is large, and the focal distance and F/# are small; furthermore, illuminance of image plane is evener, so that the eyepiece especially meets the requirements of the head-mounted display.

Description

eyepiece

technical field

The invention relates to an eyepiece, in particular to an eyepiece used in a helmet-mounted display, and belongs to the field of optical technology.

Background technique

Head Mounted Display (HMD) is a popular product in the display field in recent years, and the HMD image display device for virtual reality and augmented display has made great progress. Since the head-mounted display device is installed on the observer's head, it must be compact and light in weight to reduce the load on the observer. The helmet-mounted display is mainly composed of three parts: display components, optical lenses and the helmet. To reduce weight, the optical system is the key. However, there is a certain contradiction between the compactness of the optical system and the requirements for the imaging quality of the optical system of the helmet-mounted display. For helmet-mounted displays, the optical system is required to achieve a relatively large field of view and exit pupil diameter, because the increase in the observation field of view will also increase the observation range, and the observer can concentrate on observing high-quality dynamic images. The increase can ensure that the helmet adapts to observers with different interpupillary distances without having to adjust the interpupillary distance of the helmet, and at the same time allows the observer's eyeballs to turn freely during observation without losing the image. However, the field of view, exit pupil diameter, and focal length of the optical system are mutually restrictive. It is not easy to achieve a large field of view, a large exit pupil diameter, and a short focal length (that is, the compactness of the system). In addition, the uniformity of the illuminance of the image plane also has a significant impact on the viewing quality when using the head-mounted display, and the optical system needs to take into account the above-mentioned various requirements.

Contents of the invention

In view of the above requirements, the present invention proposes a very compact and light eyepiece, which is used in a helmet-mounted display to amplify the image displayed by the helmet-mounted micro-display device and image it through the human eye located at the diaphragm. The exit pupil diameter of the eyepiece is larger than that of ordinary eyepieces, the exit pupil distance is long, and the viewing angle is large. The micro-display is used to ensure a compact structure, so the focal length is small and the F/# is small; The incident angle of light on the image plane is less than 4 degrees, which can ensure that the illumination of the image plane is relatively uniform, which is good for human eyes to watch.

Technical scheme of the present invention is as follows:

The eyepiece of the present invention comprises six lenses, and the image side is telecentric; the eyepiece is coaxially arranged with a diaphragm, a first lens, a second lens, and a third lens in sequence along the optical axis from the human eye observation side to the display device side. lens, fourth lens, fifth lens and sixth lens;

Wherein the combined focal length of the first lens and the second lens is f12, the combined focal length of the third lens and the fourth lens is f34, the total focal length of the system is fw, the combined focal length of the first to fifth lenses is f15, and each focal length satisfies The following (1) ~ (3) relationship:

(1) 0.8<f12/fw<3

(2) 0.9＜|f34/fw|＜6

(3) 0.8<f15/fw<1.9

And the material of the lens meets the following requirements:

Nd ₄ ＞1.8, Nd ₆ ＞1.8, Vd _{1, 2, 3, 5} ＞40

Nd ₄ , Nd ₆ : Respectively represent the refractive index of the fourth lens and the sixth lens at the line d,

Vd ₁ , Vd ₂ , Vd ₃ , Vd ₅ : respectively represent the Abbe numbers of the first lens, the second lens, the third lens, and the fifth lens on the line d, all of which are greater than 40.

Preferably, each focal length of the eyepiece system also satisfies the following relational expressions (4)-(6), so as to obtain better imaging effects.

(4) 1.2<f12/fw<1.5

(5) 2<|f34/fw|<3.5

(6) 0.85<f15/fw<1.3

Preferably, the first lens and the second lens of the above-mentioned eyepiece may be positive lenses, and the third and fourth lenses constitute a positive-negative doublet lens.

Preferably, the fifth lens is a positive lens, and the sixth lens may be a positive lens or a negative lens.

Preferably, the exit pupil of the eyepiece system is smaller than or equal to 8.

The present invention also relates to a head-mounted display using the above-mentioned eyepiece, which images the image displayed on the liquid crystal display to the human eyes, and the human eyes are located at the diaphragm for observation, wherein the liquid crystal display is a micro-display with a diagonal length not greater than 3 inches, usually less than 3 inches. 1 in.

Beneficial effect

The eyepiece of the present invention has the advantages of compact structure and light weight; the exit pupil diameter of the eyepiece is larger than that of ordinary eyepieces, the exit pupil distance is long, the field of view angle is large, the focal length is small and the F/# is small; The incident angle of light on the image plane is less than 4 degrees, which can ensure that the illumination of the image plane is relatively uniform, which is good for human eyes to watch.

Description of drawings

Fig. 1 shows an optical system diagram according to a first embodiment of the present invention;

Fig. 2 shows the aberration curve of the optical system according to the first embodiment of the present invention;

Fig. 3 shows an optical system diagram according to a second embodiment of the present invention;

Fig. 4 shows the aberration curve of the optical system according to the second embodiment of the present invention;

Fig. 5 shows the optical system diagram according to the third embodiment of the present invention;

Fig. 6 shows the aberration curve of the optical system according to the third embodiment of the present invention;

Fig. 7 shows an optical system diagram according to a fourth embodiment of the present invention;

FIG. 8 shows an aberration curve of an optical system according to a fourth embodiment of the present invention;

Fig. 9 shows an optical system diagram according to a fifth embodiment of the present invention;

Fig. 10 shows the aberration curve of the optical system according to the fifth embodiment of the present invention;

Fig. 11 shows an optical system diagram according to a sixth embodiment of the present invention;

Fig. 12 shows the aberration curve of the optical system according to the sixth embodiment of the present invention;

Fig. 13 shows an optical system diagram according to a seventh embodiment of the present invention;

Fig. 14 shows the aberration curve of the optical system according to the seventh embodiment of the present invention;

Fig. 15 shows an optical system diagram according to an eighth embodiment of the present invention;

Fig. 16 shows the aberration curve of the optical system according to the eighth embodiment of the present invention;

Fig. 17 shows an optical system diagram according to a ninth embodiment of the present invention;

FIG. 18 shows aberration curves of an optical system according to a ninth embodiment of the present invention.

Detailed ways

Fig. 1 has shown the eyepiece according to the first embodiment of the present invention, as shown in Fig. 1, from human eye observation side to display device I side (from left to right), be successively diaphragm E, the first lens L1, the first lens L1 The second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6, the first lens L1 and the second lens L2 are positive lenses, and the third lens L3 and the fourth lens L4 form a positive-negative The form of doublet lens corrects the chromatic aberration of the system, the fifth lens L5 is a positive lens, and the sixth lens L6 is a negative lens. L5 and L6 correct the aberrations related to the field of view, including distortion and field curvature, and well control the system Like square telecentric properties. The surface number of the diaphragm is 1, and so on, and the surface number of the display device is 13. The eyepiece design data of the first embodiment are shown in Table 1 below.

Table 1

Fig. 3 has shown the eyepiece according to the second embodiment of the present invention, as shown in Fig. 3, from human eye observation side to display device I side, successively be diaphragm E, first lens L1, second lens L2, third lens Lens L3, fourth lens L4, fifth lens L5, and sixth lens L6, wherein the first lens L1 and the second lens L2 are positive lenses, and the third lens L3 and fourth lens L4 constitute a positive-negative doublet lens , correct the chromatic aberration of the system, the fifth lens L5 is a positive lens, the sixth lens L6 is a negative lens, L5, L6 correct the aberrations related to the field of view, including distortion and field curvature, and use the surface serial number as described in the first embodiment In order, the eyepiece design data of the second embodiment is shown in Table 2 below.

Table 2

Fig. 5 has shown the eyepiece according to the third embodiment of the present invention, as shown in Fig. 5, from human eye observation side to display device I side, successively be diaphragm E, first lens L1, second lens L2, third lens Lens L3, fourth lens L4, fifth lens L5, and sixth lens L6, wherein the first lens L1 and the second lens L2 are positive lenses, and the third lens L3 and fourth lens L4 constitute a positive-negative doublet lens , the fifth lens L5 is a positive lens, and the sixth lens L6 is a negative lens, following the order of surface numbers as described in the first embodiment, and the eyepiece design data of the third embodiment are shown in Table 3 below.

table 3

Fig. 7 has shown the eyepiece according to the 4th embodiment of the present invention, as shown in Fig. 7, from human eye observation side to display device I side (from left to right), successively be diaphragm E, first lens L1, the first lens L1 The second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6, the first lens L1 and the second lens L2 are positive lenses, and the surface of the first lens L1 toward the stop side is approximately one plane, the third lens L3 and the fourth lens L4 constitute a positive-negative doublet lens, correcting the chromatic aberration of the system, the fifth lens L5 is a positive lens, the sixth lens L6 is a negative lens, and L5 and L6 correct field-of-view related Aberrations, including distortion and curvature of field, control the telecentricity of the system well. The surface number of the diaphragm is 1, and so on, and the surface number of the display device is 13. The eyepiece design data of the fourth embodiment is shown in Table 4 below.

Table 4

Fig. 9 shows the eyepiece according to the fifth embodiment of the present invention, as shown in Fig. 9, from the human eye observation side to the display device I side (from left to right), there are diaphragm E, first lens L1, the first lens L1, The second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6, the first lens L1 and the second lens L2 are positive lenses, and the third lens L3 and the fourth lens L4 form a positive-negative lens. The form of doublet lens corrects the chromatic aberration of the system, the fifth lens L5 is a positive lens, and the sixth lens L6 is a negative lens. L5 and L6 correct the aberrations related to the field of view, including distortion and field curvature, and well control the system Like square telecentric properties. The surface number of the diaphragm is 1, and so on, and the surface number of the display device is 13. The eyepiece design data of the fifth embodiment is shown in Table 5 below.

table 5

Fig. 11 has shown the eyepiece according to the 6th embodiment of the present invention, as shown in Fig. 11, from human eye observation side to display device I side (from left to right), successively be aperture E, first lens L1, the first lens L1 The second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6, the first lens L1 and the second lens L2 are positive lenses, and the surface of the first lens L1 toward the stop side is approximately one plane, the third lens L3 and the fourth lens L4 constitute a positive-negative doublet lens, correcting the chromatic aberration of the system, the fifth lens L5 is a positive lens, the sixth lens L6 is a negative lens, and L5 and L6 correct field-of-view related Aberrations, including distortion and curvature of field, control the telecentricity of the system well. The surface number of the diaphragm is 1, and so on, and the surface number of the display device is 13. The eyepiece design data of the sixth embodiment is shown in Table 6 below.

Table 6

Fig. 13 shows the eyepiece according to the seventh embodiment of the present invention. As shown in Fig. 13, from the human eye observation side to the display device I side, there are diaphragm E, first lens L1, second lens L2, third lens L Lens L3, fourth lens L4, fifth lens L5, and sixth lens L6, wherein the first lens L1 and the second lens L2 are positive lenses, the surface of the first lens L1 toward the diaphragm side is approximately a plane, and the third lens L3 and the fourth lens L4 constitute a positive-negative doublet lens, the fifth lens L5 is a meniscus positive lens and bends toward the direction of the fourth lens L4, and the sixth lens L6 is a meniscus positive lens and bends toward the fourth lens L4. The five-lens L5 direction follows the sequence of surface numbers as described in the first embodiment, and the eyepiece design data of the seventh embodiment is shown in Table 7 below.

Table 7

Fig. 15 shows the eyepiece according to the eighth embodiment of the present invention. As shown in Fig. 15, from the human eye observation side to the display device I side, there are successively diaphragm E, first lens L1, second lens L2, third lens Lens L3, fourth lens L4, fifth lens L5, and sixth lens L6, wherein the first lens L1 and the second lens L2 are positive lenses, and the third lens L3 and fourth lens L4 constitute a positive-negative doublet lens , the fifth lens L5 is a positive meniscus lens and bends toward the direction of the fourth lens L4, the sixth lens L6 is a positive meniscus lens and bends toward the direction of the fifth lens L5, and uses the surface numbers as described in the first embodiment In order, the eyepiece design data of the eighth embodiment is shown in Table 8 below.

Table 8

Fig. 17 shows the eyepiece according to the ninth embodiment of the present invention. As shown in Fig. 17, from the human eye observation side to the display device I side (from left to right), there are diaphragm E, first lens L1, the first lens L1, The second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6, the first lens L1 and the second lens L2 are positive lenses, and the third lens L3 and the fourth lens L4 form a positive-negative lens. The form of doublet lens corrects the chromatic aberration of the system, the fifth lens L5 is a positive lens, and the sixth lens L6 is a negative lens. L5 and L6 correct the aberrations related to the field of view, including distortion and field curvature, and well control the system Like square telecentric properties. The surface number of the diaphragm is 1, and so on, and the surface number of the display device is 13. The eyepiece design data of the ninth embodiment is shown in Table 9 below.

Table 9

From the various data of the above-mentioned embodiments of the present invention, it can be concluded that the eyepieces of the first to ninth embodiments meet the requirements of the aforementioned relational expressions, and the results are shown in Table 10.

Table 10

f12/fw |f34/fw| f15/fw Nd ₄ Nd ₆ Vd ₁ Vd _{2 Vd3} Vd ₅ Example 1 1.434 3.139 0.901 1.847 1.847 58.71 44.85 44.85 53.58 Example 2 1.237 1.974 0.908 1.847 1.847 49.41 46.51 44.85 44.85 Example 3 1.294 2.199 0.909 1.847 1.847 59.38 45.54 44.85 44.85 Example 4 1.374 2.818 0.938 1.847 1.847 50.99 45.30 44.85 44.85 Example 5 1.247 2.069 0.901 1.847 1.847 49.78 48.07 44.85 44.85 Example 6 1.355 2.675 0.955 1.847 1.847 44.85 44.85 44.85 44.85 Example 7 1.286 2.050 1.197 1.847 1.847 44.85 46.71 46.57 44.85 Example 8 1.292 2.127 1.180 1.847 1.847 45.24 44.97 46.43 44.85

Example 9 1.350 2.620 0.964 1.847 1.847 44.85 44.85 44.85 44.85

Although the embodiments of the invention have been shown in detail, it is to be understood that modifications and adaptations to these embodiments may occur to those skilled in the art without departing from the scope of the invention as set forth in the appended claims.

Claims (9)

1. an eyepiece comprises six-element lens, as Fang Yuanxin, described eyepiece from the eye-observation side to the display device side, along coaxial diaphragm, first lens, second lens, the 3rd lens, the 4th lens, the 5th lens and the 6th lens of being arranged in order of optical axis direction;

The combined focal length f12 of first lens and second lens wherein, the combined focal length f34 of the 3rd lens and the 4th lens, the combined focal length f15 of the total focal distance f w of system and first to the 5th lens satisfies following relational expression (1)～(3):

(1)0.8＜f12/fw＜3

(2)0.9＜|f34/fw|＜6

(3)0.8＜f15/fw＜1.9

And the material of described lens satisfies following requirement:

Nd ₄＞1.8, Nd ₆＞1.8, Nd ₄, Nd ₆Represent the 4th lens, the 6th lens refractive index respectively at the d line,

Vd ₁, Vd ₂, Vd ₃, Vd ₅All greater than 40, Vd ₁, Vd ₂, Vd ₃, Vd ₅Represent first lens, second lens, the 3rd lens, the 5th lens Abbe number respectively at the d line.

2. eyepiece as claimed in claim 1 is characterized in that first lens and second lens are positive lens.

3. eyepiece as claimed in claim 2 is characterized in that described first lens are protruding in the diaphragm side towards the face of diaphragm one side, radius-of-curvature be on the occasion of.

4. eyepiece as claimed in claim 3 is characterized in that the 5th lens are positive lens.

5. eyepiece as claimed in claim 1 is characterized in that the 3rd lens and the 4th lens are just forming-cemented doublet of negative form.

6. eyepiece as claimed in claim 1 is characterized in that diaphragm face and the distance of first lens between the face of diaphragm face are 19mm.

7. eyepiece as claimed in claim 1 is characterized in that: described focal length also satisfies following relational expression (4)～(6),

(4)1.2＜f12/fw＜1.5

(5)2＜|f34/fw|＜3.5

(6)0.85＜f15/fw＜1.3。

8. eyepiece as claimed in claim 1 is characterized in that: the exit pupil diameter of described eyepiece is less than or equal to 8mm.

9. Helmet Mounted Display comprises a liquid crystal micro display and as arbitrary eyepiece as described in the claim 1-8, it is characterized in that: fail to grow up in 3 inches in the diagonal angle of described liquid crystal micro display.

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