JP3304497B2 - Eyepiece for visual display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable visual display device, and more particularly to an eyepiece of a head or face-mounted visual device that can be held on the head or face of an observer.

[0002]

2. Description of the Related Art In recent years, large-screen, high-definition devices have been used as visual display devices such as televisions and computer displays. For this reason, CRT
The display devices represented by such devices are becoming larger and larger. This is the same in the liquid crystal display device. Therefore, a head-mounted visual display device that can obtain a high-definition large-screen observation image despite its small size has attracted attention.

As an eyepiece of such a conventional head-mounted visual display device, there is a method of enlarging and projecting a two-dimensional image display element using only an aspheric single lens (Japanese Patent Publication No. 4-42650). FIG. 17 shows an optical system of the head-mounted visual display device. In FIG. 17, assume that the two-dimensional image display element is 5, the eyepiece for projecting the two-dimensional image display element 5 in the air is 2 and the observer's eyeball position is 10. This conventional technique has an advantage that the optical system is simple,
If the amount of projection of the two-dimensional image display element 5 from the head of the observer increases, and if the observation angle of view is widened, the positive single lens of the eyepiece 2 becomes large, and the entire apparatus becomes large. There were problems such as a deterioration in the feeling of wearing.

[0004]

Hereinafter, the problems to be solved by the present invention in relation to the prior art will be described in detail. For a head-mounted visual device, reducing the size of the entire device and reducing the weight of the device are important points in order not to impair the wearability. The factor that determines this depends on how the eyepiece optical system is made compact and lightweight.

Further, it is necessary to secure a large angle of view in order to increase the sense of reality during image observation, and it is not an exaggeration to say that the sense of reality of an image is determined by the angle of view presented. John Society Journal Vol.45, No.1
2, pp. 1589-1596 (1991)). In order to give the observer a sense of realism such as a three-dimensional feeling and a powerful feeling, it is necessary to secure a presentation angle of view of 30 ° (± 15 °) or more in the horizontal direction, and at the same time, 120 ° (± 60 °) ), It is known that the effect is saturated. That is,
It is desirable that the viewing angle of view be 30 ° or more and as close as possible to 120 °.

However, when the observation angle of view is widened, it becomes difficult to correct the aberration of the eyepiece optical system, and the resolution of the peripheral image is reduced, and the occurrence of image distortion is increased, and the observed image is distorted. In practice, about 70 ° is the limit of the observation angle of view.

Also in this case, the number of components of the lens system increases, the size of the optical system increases, and the weight of the entire apparatus also increases.

Even if such an eyepiece lens system is constituted by a single lens to reduce the size and weight, the occurrence of coma and distortion at the periphery of the observed image cannot be ignored at an observation angle of view exceeding 20 °. However, the resolution around the observation angle of view is reduced.

Therefore, it has been considered that the eyepiece lens system is constituted by a single lens having an aspherical surface. However, even if the generation of coma and distortion is suppressed, at an angle of view exceeding an angle of view of 30 °, Since the correction capability of the chromatic aberration and the field curvature of the aspherical single lens approaches the limit, it becomes impossible to provide an image with good resolution to the observer. This is the same even if both surfaces of the single lens are aspherical.

When the eyepiece lens system is composed of an aspherical single lens, the aberrations that can be corrected by the aspherical surface are mainly distortion and coma, and chromatic aberration and Petzval sum cannot be corrected.
In the case of a viewing angle of 30 ° or less, an aberration level that does not cause a practical problem occurs even if the lens is formed of an aspherical single lens.
If an angle of view exceeding 0 ° is to be ensured, chromatic aberration of magnification in the chromatic aberration and Petzval's sum will cause remarkable occurrence of field curvature aberration, making it impossible to correct even if any aspherical surface is used. .

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and its object is to achieve the object of 30 ° (± 15 °).
°) It is an object of the present invention to provide an eyepiece for a visual display device that can observe an observation angle of view of more than the above and can observe a flat and clear observation image up to the periphery.

[0012]

According to the present invention, there is provided an eyepiece for a visual display device which achieves the above object, comprising: a two-dimensional display element having a substantially planar image display surface for displaying an observation image;
An eyepiece used in a visual display device comprising: a conversion optical element for converting a plane image of the two-dimensional display element into a curved surface image; and an eyepiece having a positive refractive power for enlarging and projecting the curved surface image as a plane image. The lens is composed of a biconvex positive lens composed of at least one aspheric surface and two or more glass types. The Abbe number of the glass material having a larger Abbe number is ν _d1 , and the Abbe number of the glass material having a smaller Abbe number is ν and _d2, the radius of curvature of the curved surface image converted by the conversion optical element R, and the focal length of the eyepiece and _{F, 14 <ν d1 -ν d2} ... (1) 1 <| R / F | <3 ... (2) The above condition is satisfied, and the at least one aspherical surface is an aspherical surface configured such that a radius of curvature increases as the distance from the optical axis increases.

[0013]

The reason and operation of the above configuration will be described below. As shown in JP-A-4-336515, an enlarged eyepiece using at least one aspherical surface is:
There are many proposals, including eyepieces for microscopes. But,
Particularly important in the eyepiece of the head-mounted visual display device is reduction in size and weight of the eyepiece. It is generally well known that it is important to reduce the number of lens components in order to solve such a problem. However, reducing the number of components of the lens system increases the aberration generated by each lens, and
This means that there is no lens system for correcting the generated aberration, which makes it difficult to correct the aberration. As a result, the observation angle of view cannot be made large.

For example, if an eyepiece optical system is constituted by a single lens, a large distortion will occur, and coma and astigmatism will also occur. As a result, the observation field angle is limited to about 20 °. .

JP-A-4-336515 is an example in which an aspherical surface is introduced to solve such a problem. The use of an aspherical surface can particularly improve distortion and coma, but cannot correct up to the occurrence of chromatic aberration of magnification and field curvature aberration due to Petzval sum. Therefore, the observation field angle is limited to a practically usable range up to about 30 °.

The important points constituting the present invention are the following two points, and these two points will be described in order. The first feature of the present invention is that chromatic aberration correction using two types of glass is performed in order to satisfactorily correct the chromatic aberration of the magnification. As a result, it is possible to satisfactorily correct the chromatic aberration of magnification, and it is possible to sufficiently correct the chromatic aberration up to nearly 50 ° for practical use.

The second characteristic of the present invention is that, in order to satisfactorily correct the field curvature aberration, a conversion optical element that converts a plane image of a two-dimensional image display element into a curved surface, and a curved object point is converted by an eyepiece. This is a configuration in which a plane image of a distant place is enlarged and projected into the air. This configuration is because it is important to convert the object surface of the two-dimensional image display element, which is a flat surface, into a curved object point in advance by using the conversion optical element so that the object plane is canceled by the curvature of field of the eyepiece optical system. Accordingly, it is not necessary to correct the field curvature aberration with the eyepiece lens system, and the eyepiece lens system can be constituted by one group of lenses as in the present invention.

By adopting the above configuration, a flat aerial enlarged image can be provided if only astigmatism is corrected without correcting field curvature aberration, that is, Petzval sum, in a group of lens systems. be able to.

Hereinafter, for convenience of design, the explanation will be made by using the surface number by the reverse tracing method when the ray is traced in reverse from the observer's eye side. The condition for correcting the chromatic aberration of magnification is determined by the difference between the Abbe numbers of the two glass materials. In the case of the present invention, it is important to select a glass type satisfying the following conditional expression. When the Abbe number of the glass material having the larger Abbe number is ν _d1 and the Abbe number of the glass material having the smaller Abbe number is ν _d2 , it is important to satisfy the following condition: 14 <ν _d1 −ν _d2 (1) It is.

If the difference in Abbe number is less than 14 below the lower limit of the conditional expression, the amount of chromatic aberration is insufficiently corrected, the occurrence of chromatic aberration of magnification cannot be corrected, and the resolving power of the peripheral angle of view is reduced.

Next, the conditional expression for the radius of curvature of the curved object surface will be described. Assuming that the radius of curvature of the image plane of the eyepiece system in reverse tracking is R, and the focal length of the eyepiece system is F, it is important to satisfy the following condition: 1 <| R / F | <3 (2) .

If the lower limit of the conditional expression (1) is exceeded, the radius of curvature of the object surface for correcting the curvature of field of the eyepiece system in the reverse tracking becomes too small. When trying to match the curvature, astigmatism becomes too large, and the resolving power of the peripheral image decreases. In addition, the upper limit of 3
Is exceeded, the astigmatism increases in the opposite direction, and the resolution of the peripheral image also decreases. in this way,
In order to balance astigmatism and coma, a good result can be obtained if the above condition is satisfied.

The shape of at least one aspherical surface is as follows:
It is important to make the aspherical surface such that the partial radius of curvature of the aspherical surface increases as the distance from the optical axis increases. This is because the shape of the aspherical surface is for reducing the occurrence of coma aberration, and it is impossible to correct the aspherical surface on another surface.

Next, the conversion optical element, which is the second item of the present invention, will be described. The conversion optical element as described above can be used as a conversion optical element, for example, by being configured with a relay lens system that intentionally generates a field curvature.

If there is no conversion optical element, the two-dimensional image display element is manufactured on a curved surface, which is very difficult due to manufacturing problems. Therefore, by adding a conversion optical element that converts a two-dimensional image displayed on a plane into a curved surface with a concave surface facing the eyepiece optical system side, even if field curvature aberration remains in the eyepiece lens system, If a curved object point is projected by an eyepiece system having a curvature of field, it is possible to enlarge and project as a planar aerial image.

As described above, the conversion optical element can be constituted by a relay lens system which intentionally generates a field curvature, or is constituted by an image fiber plate or the like having a curved end surface. Is also possible.

More preferably, at least one aspherical surface of the eyepiece is provided on the third image side closest to the image in the reverse tracking for aberration correction. This is because the height of the off-axis marginal ray becomes highest on the third surface, and the off-axis aberration can be controlled by making the third surface aspherical.

More preferably, it is more advantageous to shorten the focal length of the eyepiece from the size of the entire apparatus.
Distance between eyepiece and observer's pupil position (eye point)
Is required to be 12 mm or more, it is important that the focal length F of the eyepiece lens satisfies the following condition: 12 <F <25 [mm] (3)

If the lower limit of 12 mm is exceeded, the focal length of the eyepiece becomes too short, and it becomes impossible to secure a distance (eye point) of 12 mm or more between the eyepiece and the pupil position of the observer. Eyelashes hit the eyepiece, making it difficult to observe. In addition, the upper limit of 25 mm
When the value exceeds, the eyepiece becomes too large and heavy, and the whole apparatus becomes heavier and heavier, giving the observer an uncomfortable feeling and a feeling of fatigue when wearing the apparatus.

Next, when the radius of curvature of the first surface is R ₁ and the radius of curvature of the third surface is R ₃ , the following condition is satisfied: 0.4 <| R ₁ / R ₃ | <2.5 (4) It is important to satisfy

This conditional expression represents the ratio of the refractive power of the first surface to the refractive power of the third surface. The principal point of the eyepiece system is located on the two-dimensional image display element side or on the eyeball position side of the observer. Is represented. If the lower limit of 0.4 is exceeded, the refractive power of the first surface becomes stronger than that of the third surface, the refractive power of the first surface becomes too strong, and the coma generated on the first surface becomes too large. The peripheral resolution is reduced. Further, even if it is attempted to correct this coma aberration on another surface, it is impossible on another surface. When the value exceeds the upper limit of 2.5, the principal point position of the eyepiece lens system comes to the observer's eye side, so that the eye point can be increased. However, this time, the coma aberration generated on the third surface and the astigmatism Occurrence of aberrations increases, and it becomes impossible to correct even if an aspherical surface is introduced.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments 1 to 12 of an eyepiece for a visual display device according to the present invention will be described below with reference to the drawings. FIG. 1 shows a lens cross section of the first embodiment, and FIG. 2 shows a lens cross section of the sixth embodiment.

1 and 2, reference numeral 1 denotes an entrance pupil position of an eyepiece corresponding to an iris position of an observer's eyeball, reference numeral 2 denotes an eyepiece, and reference numeral 3 denotes a curved image plane. Depending on.

The curved image plane 3 includes a relay optical system 4 intentionally generating a field curvature as shown in FIG. 3, an image fiber plate 6 as shown in FIG. 4, and the like. It is obtained by converting the plane image plane of the two-dimensional image display element 5 by the conversion optical element. Note that the display surface of the two-dimensional image display element 5 may be curved to form the curved image surface 3.

Now, the eyepiece 2 is shown in FIGS.
1 to 12, as shown in FIG. 1, a negative meniscus lens having a convex surface directed from the entrance pupil position 1 side to the entrance pupil position 1 side and a biconvex lens are bonded to each other. In Example 6, as shown in FIG. 2, a biconvex lens and a negative meniscus lens having a convex surface facing the image plane 3 side from the entrance pupil position 1 side are adhered to each other.

In the first embodiment, an aspherical surface is used for the third surface of the eyepiece 2, and the observation field angle is 30 ° (± 1) in the horizontal direction.
5 °), 37.8 ° diagonally and the focal length is F
= 23.3365 mm, entrance pupil diameter 4 mm.

In the second embodiment, an aspherical surface is used for the first and third surfaces of the eyepiece, and the observation angle of view is 30 ° in the horizontal direction.
(± 15 °), 37.8 ° in the diagonal direction, the focal length is F = 24.052 mm, and the entrance pupil diameter is 4 mm.

In the third embodiment, an aspherical surface is used for the first to third surfaces of the eyepiece, and the angle of view is 30 ° in the horizontal direction.
(± 15 °), 37.8 ° in the diagonal direction, the focal length is F = 22.965 mm, and the entrance pupil diameter is 4 mm.

In the fourth embodiment, an aspherical surface is used for the third surface of the eyepiece, and the observation field angle is 30 ° (± 15 °) in the horizontal direction.
°), 37.8 ° diagonally and the focal length is F =
18.895 mm, entrance pupil diameter 4 mm.

In the fifth embodiment, an aspherical surface is used for the third surface of the eyepiece, and the observation field angle is 30 ° (± 15 °) in the horizontal direction.
°), 37.8 ° diagonally and the focal length is F =
25.726 mm and the entrance pupil diameter is 4 mm.

In the sixth embodiment, an aspherical surface is used for the third surface of the eyepiece 2, and the observation field angle is 30 ° (± 1) in the horizontal direction.
5 °), 37.8 ° diagonally and the focal length is F
= 26.304 mm, and the entrance pupil diameter is 4 mm.

In the seventh embodiment, an aspherical surface is used for the first to third surfaces of the eyepiece, and the observation angle of view is 40 ° in the horizontal direction.
(± 20 °), 50.4 ° in the diagonal direction, the focal length is F = 19.9984 mm, and the entrance pupil diameter is 4 mm.

In the eighth embodiment, an aspherical surface is used for the third surface of the eyepiece, and the observation angle of view is 40 ° (± 20 °) in the horizontal direction.
°), 50.4 ° diagonally and the focal length is F =
The diameter is 15.1818 mm and the entrance pupil diameter is 4 mm.

In the ninth embodiment, an aspherical surface is used for the third surface of the eyepiece, and the observation field angle is 50 ° (± 25 °) in the horizontal direction.
°), 63.1 ° in the diagonal direction, and the focal length is F =
17.3167 mm and the entrance pupil diameter is 4 mm.

In the tenth embodiment, the first surface, the third
An aspherical surface is used, and the observation angle of view is 50 in the horizontal direction.
° (± 25 °), 63.1 ° in the diagonal direction, the focal length is F = 16.5402 mm, and the entrance pupil diameter is 4 mm.

In the eleventh embodiment, the first to third surfaces of the eyepiece are described.
An aspherical surface is used, and the observation angle of view is 50 in the horizontal direction.
° (± 25 °), 63.1 ° in the diagonal direction, the focal length is F = 15.0796 mm, and the entrance pupil diameter is 4 mm.

In the twelfth embodiment, an aspherical surface is used for the third surface of the eyepiece, and the observation angle of view is 50 ° (± 2 °) in the horizontal direction.
5 °), 63.1 ° in the diagonal direction, and the focal length is F
= 20.2986 mm and the entrance pupil diameter is 4 mm.

[0048] Hereinafter, shows lens data of the reverse track of the Examples 1 to 12 but the symbols are outside of the, r ₀ is the pupil position 1
, D ₀ is the eye point, and r ₁ to r ₃ are the eyepieces 2
Are the radii of curvature of the respective lens surfaces, d ₁ and d ₂ are the eyepieces 2
, N _d1 and n _d2 are the refractive indices of the d-line of each lens of the eyepiece 2, ν _d1 and ν _d2 are the Abbe numbers of each lens of the eyepiece 2, and d ₃ is the eyepiece. The distance between the last surface (third surface) of the lens 2 and the image plane 3, and r ₄ represents the image plane 3. Further, the aspherical shape has a distance Z from an arbitrary point on the aspherical surface to a tangent plane of the aspherical vertex, a distance h from the arbitrary point to the optical axis, a reference radius of curvature r, and a conic constant. When K and the aspheric coefficient are A, B,..., It is expressed by the following equation. In ^{Z = (h 2 / r)} / {1+ [1- (1 + K) (h / r) 2 ] ^{1/2} + Ah 4 + Bh 6} + ···· ... (5) However, h = X ² + Y ² is there.

Example 1 r ₀ = (pupil position) d ₀ = 15.000 r ₁ = 21.5489 d ₁ = 5.800 nd ₁ = 1.84660 ν _d1 = 23.9 r ₂ = 12.5356 d ₂ = 5.669 nd ₂ = 1.62041 ν _d2 = 60.3 r ₃ = -25.4354 _{(aspherical) d 3 = 18.551 r 4 =} -33.5251 third surface K = -4.816485 aspherical coefficients ^{A = -0.102230 × 10 -4 B =} 0 ν d1 -ν d2 = 60.3-23.9 = 36.4 | R / F | = | -33.53 / 23.34 | = 1.44 | R 1 / R 3 | = | 21.55 /-25.44|= 0.85
.

Example 2 r ₀ = (pupil position) d ₀ = 15.002 r ₁ = 18.7558 (aspherical surface) d ₁ = 6.299 nd ₁ = 1.84660 ν _d1 = 23.9 r ₂ = 11.0076 d ₂ = 5.700 nd ₂ = 1.62041 ν _d2 = 60.3 r ₃ = -33.5874 _{(aspherical) d 3 = 18.000 r 4 =} -32.7505 aspherical coefficients first surface K = -0.411383 A = 0.469754 × 10 -5 B = 0.420315 × 10 -7 third surface K = -7.120948 A = 0.267076 × 10 ^-5 B = 0 ν _d1 −ν _d2 = 60.3−23.9 = 36.4 | R / F | = | −32.75 / 24.05 | = 1.36 | R ₁ / R ₃ | = | 18.76 / −33.59 | = 0.56
.

Embodiment 3 r ₀ = (pupil position) d ₀ = 15.001 r ₁ = 18.0810 (aspherical surface) d ₁ = 5.234 nd ₁ = 1.84660 ν _d1 = 23.9 r ₂ = 10.6679 (aspherical surface) d ₂ = 6.729 n _d2 = 1.62041 ν _d2 = 60.3 r ₃ = -30.7567 (aspheric surface) d ₃ = 17.205 r ₄ = -33.3410 First surface K = -0.700102 A = 0.106320 × 10 ^-4 B = 0.283749 × 10 ^-7 Second surface K = 0.064525 A = 0.434571 × 10 ^-4 B = -0.168414 × 10 ^-5 Third surface K = -12.193362 A = -0.442040 × 10 ^-4 B = 0.623315 × 10 ^-6 ν _d1 -ν _d2 = 60.3-23.9 = 36.4 | R / F | = | -33.34 / 22.96 | = 1.45 | R 1 / R 3 | = | 18.08 /-30.76|= 0.59
.

Example 4 r ₀ = (pupil position) d ₀ = 15.000 r ₁ = 17.2162 d ₁ = 2.500 nd ₁ = 1.84660 ν _d1 = 23.9 r ₂ = 10.6399 d ₂ = 7.390 nd ₂ = 1.62041 ν _d2 = 60.3 r ₃ = -21.0275 _{(aspherical) d 3 = 15.110 r 4 =} -27.5534 aspherical coefficients third surface K = -10.60884 A = -0.639428 × 10 -4 B = 0.312648 × 10 -6 ν d1 -ν d2 = 60.3- 23.9 = 36.4 | R / F | = | -27.55 / 18.90 | = 1.46 | R 1 / R 3 | = | 17.22 /-21.03|= 0.82
.

[0053] Example 5 r ₀ = (pupil _{position) d 0 = 15.000 r 1 =} 20.3804 d 1 = 2.500 n d1 = 1.79500 ν d1 = 45.3 r 2 = 11.1948 d 2 = 6.794 n d2 = 1.62041 ν d2 = 60.3 r ₃ = -35.8353 (aspheric surface) d ₃ = 21.712 r ₄ = -65.48284 Aspheric surface third surface K = -21.60884 A = -0.249510 × 10 ^-4 B = 0 ν _d1 −ν _d2 = 60.3−45.3 = 15.0 | R / F | = | -65.48 / 25.73 | = 2.54 | R 1 / R 3 | = | 20.38 /-35.84|= 0.57
.

Example 6 r ₀ = (pupil position) d ₀ = 15.000 r ₁ = 17.3935 d ₁ = 8.000 nd ₁ = 1.62041 ν _d1 = 60.3 r ₂ = -15.5421 d ₂ = 8.000 _{nd 2} = 1.79500 ν _d2 = 45.3 r ₃ = -48.3849 (aspheric surface) d ₃ = 18.575 r ₄ = -56.31109 aspheric surface third surface K = -13.415666 A = 0.280647 × 10 ^-4 B = 0 ν _d1 −ν _d2 = 60.3−45.3 = 15.0 | R / F | = | -56.31 / 26.30 | = 2.14 | R 1 / R 3 | = | 17.39 /-48.38|= 0.36 example 7 r ₀ = (pupil _{position) d 0 = 15.002 r 1 =} 17.9080 ( aspherical _{) d 1 = 5.470 n d1 =} 1.84660 ν d1 = 23.9 r 2 = 9.3948 ( _{aspherical) d 2 = 10.909 n d2 =} 1.62041 ν d2 = 60.3 r 3 = -18.0303 ( _{aspherical) d 3 = 13.620 r 4 =} - 32.3658 First surface K = 0.080234 A = -0.156333 × 10 ^-4 B = -0.431237 × 10 ^-7 Second surface K = -0.640682 A = -0.630077 × 10 ^-5 B = -0.889580 × 10 ^-7 Third surface K ^{= -8.207213 A = -0.682298 × 10 -4} B = 0.460933 × 10 -6 ν d1 -ν d2 = 60.3-23.9 = 36.4 | R / | = | -32.37 / 20.00 | = 1.62 | R 1 / R 3 | = | 17.91 /-18.03|= 0.99
.

Example 8 r ₀ = (pupil position) d ₀ = 15.000 r ₁ = 15.5682 d ₁ = 2.500 nd ₁ = 1.84660 ν _d1 = 23.9 r ₂ = 10.7162 d ₂ = 12.521 nd ₂ = 1.62041 ν _d2 = 60.3 r ₃ = -13.1358 _{(aspherical) d 3 = 9.978 r 4 =} -28.2141 third surface K = -2.542008 aspherical coefficients ^{A = 0.777350 × 10 -4 B =} 0 ν d1 -ν d2 = 60.3-23.9 = 36.4 | R / F | = | -28.21 / 15.18 | = 1.86 | R 1 / R 3 | = | 15.57 /-13.14|= 1.19
.

Example 9 r ₀ = (pupil position) d ₀ = 15.000 r ₁ = 22.8036 d ₁ = 2.500 n _d1 = 1.84660 v _d1 = 23.9 r ₂ = 15.6474 d ₂ = 14.739 n _d2 = 1.62041 v _d2 = 60.3 r ₃ = -13.3094 _{(aspherical) d 3 = 12.761 r 4 =} -35.3690 third surface K = -2.231257 aspherical coefficients ^{A = 0.192329 × 10 -4 B =} 0 ν d1 -ν d2 = 60.3-23.9 = 36.4 | R / F | = | -35.37 / 17.32 | = 2.04 | R 1 / R 3 | = | 22.80 /-13.31|= 1.71
.

Example 10 r ₀ = (pupil position) d ₀ = 15.000 r ₁ = 20.6169 (aspherical surface) d ₁ = 2.500 nd ₁ = 1.84660 ν _d1 = 23.9 r ₂ = 14.8332 d ₂ = 11.179 nd ₂ = 1.62041 ν _d2 = 60.3 r ₃ = -12.4068 _{(aspherical) d 3 = 11.179 r 4 =} -34.2441 aspherical coefficients first surface K = 0.056745 A = -0.894154 × 10 -5 B = 0.724808 × 10 -8 third surface K = ^{-2.905002 A = 0.442459 × 10 -5 B} = 0 ν d1 -ν d2 = 60.3-23.9 = 36.4 | R / F | = | -34.24 / 16.54 | = 2.07 | R 1 / R 3 | = | 20.62 /-12.41 | = 1.66
.

Embodiment 11 r ₀ = (pupil position) d ₀ = 15.000 r ₁ = 22.1333 (aspheric surface) d ₁ = 2.500 n _d1 = 1.84660 ν _d1 = 23.9 r ₂ = 18.0466 (aspheric surface) d ₂ = 17.493 n _d2 = 1.62041 ν _d2 = 60.3 r ₃ = -10.3053 (aspherical surface) d ₃ = 10.006 r ₄ = -40.2685 First surface K = 0.460822 A = 0.133503 × 10 ^-4 B = -0.160835 × 10 ^-6 Second surface K = −0.289289 A = 0.214610 × 10 ⁻³ B = −0.834993 × 10 ⁻⁶ Third surface K = −3.278657 A = −0.600474 × 10 ⁻⁴ B = 0.223437 × 10 ⁻⁶ ν _d1 −ν _d2 = 60.3−23.9 = 36.4 | R / F | = | -40.27 / 15.08 | = 2.67 | R 1 / R 3 | = | 22.13 /-10.31|= 2.15
.

Example 12 r ₀ = (pupil position) d ₀ = 15.000 r ₁ = 28.8302 d ₁ = 4.665 nd ₁ = 1.84660 ν _d1 = 23.9 r ₂ = 17.1240 d ₂ = 14.697 nd ₂ = 1.62041 ν _d2 = 60.3 r ₃ = -14.8762 _{(aspherical) d 3 = 15.638 r 4 =} -34.7933 third surface K = -2.658889 aspherical coefficients ^{A = -0.117671 × 10 -4 B =} 0 ν d1 -ν d2 = 60.3-23.9 = 36.4 | R / F | = | -34.79 / 20.30 | = 1.71 | R 1 / R 3 | = | 28.83 /-14.88|= 1.94
.

Next, aberration diagrams representing spherical aberration, astigmatism, distortion, and lateral aberration of the above-mentioned Examples 1 to 12 are shown in FIG.
To FIG.

[0061]

As is apparent from the above description, according to the eyepiece for a visual display device of the present invention, a clear image can be obtained with a wide angle of view because it is possible to clearly observe a wide angle of view and a peripheral angle of view. A head-mounted display device capable of observation can be provided.

[Brief description of the drawings]

FIG. 1 is a lens cross-sectional view of an eyepiece for a visual display device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a lens according to a sixth embodiment.

FIG. 3 is a diagram showing an optical system of a visual display device using a relay optical system as a conversion optical element.

FIG. 4 is a diagram showing an optical system of a visual display device using an image fiber plate as a conversion optical element.

5 is an aberration diagram showing a spherical aberration, an astigmatism, a distortion, and a lateral aberration of Example 1. FIG.

FIG. 6 is an aberration diagram similar to FIG. 5 of the second embodiment.

FIG. 7 is an aberration diagram similar to FIG. 5 of the third embodiment.

FIG. 8 is an aberration diagram similar to FIG. 5 of the fourth embodiment.

FIG. 9 is an aberration diagram similar to FIG. 5 of the fifth embodiment.

FIG. 10 is an aberration diagram similar to FIG. 5 of the sixth embodiment.

FIG. 11 is an aberration diagram similar to FIG. 5 in the seventh embodiment.

FIG. 12 is an aberration diagram similar to FIG. 5 of the eighth embodiment.

FIG. 13 is an aberration diagram similar to FIG. 5 of the ninth embodiment.

FIG. 14 is an aberration diagram similar to FIG. 5 of the tenth embodiment.

FIG. 15 is an aberration diagram similar to FIG. 5 of the eleventh embodiment.

FIG. 16 is an aberration diagram similar to FIG. 5 in Example 12.

FIG. 17 is a diagram showing an optical system of a conventional head-mounted visual display device.

[Explanation of symbols]

 Reference Signs List 1: entrance pupil position of eyepiece lens 2: eyepiece lens 3: curved image surface 4: relay optical system 5: two-dimensional image display device 6: image fiber plate

Continuation of front page (56) References JP-A-3-101709 (JP, A) JP-A-4-159509 (JP, A) JP-A-4-177313 (JP, A) JP-A-4-52615 (JP) JP-A-63-30008 (JP, A) JP-A-5-303056 (JP, A) JP-A-5-303054 (JP, A) JP-T-61-501946 (JP, A) (58) Surveyed fields (Int.Cl. ⁷ , DB name) G02B 9/00-17/08 G02B 21/02-21/04 G02B 25/00-25/04 G02B 27/02

Claims (4)

(57) [Claims] An image display surface for displaying an observation image is substantially flat.
A two-dimensional display element configured to Jo, vision consists of a converting optical element for converting the planar image of the two-dimensional display device into a curved image, a positive refractive power of the ocular lens for enlarging and projecting the curved surface image as a planar image In an eyepiece used for a display device,
Whether the eyepiece at least one aspheric surface and a biconvex positive lens consisting of two or more glass type Rannahli, the glass material having a larger Abbe number Abbe number [nu _d1, the glass material having a smaller Abbe number If the Abbe number is ν _d2 , the radius of curvature of the surface of the curved image converted by the conversion optical element is R, and the focal length of the eyepiece is F, 14 <ν _d1 −ν _d2 (1) 1 <| R / F | <3 (2) A visual display characterized by satisfying the following condition, wherein the at least one aspherical surface is an aspherical surface configured such that a radius of curvature increases as the distance from the optical axis increases. Eyepiece for device. 2. An eyepiece for a visual display device according to claim 1, wherein said at least one aspherical surface is disposed on a surface of said eyepiece closest to said curved surface image. 3. The system according to claim 2, wherein a distance (eye point) between a surface closest to the pupil of the eyepiece and the pupil is 12 mm or more, and satisfies the following condition (3). Eyepieces for visual display devices. 12 <F <25 [mm] (3) 4. The most pupil-side surface of the eyepiece (first surface)
The radius of curvature of the surface (R ₁ ) is R ₁ , and the surface (the third
When the radius of curvature of the surface) is R ₃ , the following condition (4)
The eyepiece for a visual display device according to claim 3, wherein: 0.4 <| R ₁ / R ₃ | <2.5 (4)