CN216526488U - Optical projection lens and display system - Google Patents

Abstract

The application provides an optical projection lens and a display system, wherein the optical projection lens comprises six lenses, namely a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a second lens from an object side to an image side, the first lens, the fourth lens and the fifth lens have negative focal power, the second lens, the third lens and the sixth lens have positive focal power, the refractive index of each lens is 1.8-2.0, the Abbe number of each lens is 15-50, and the thickness of each lens is 0.5-1.5 mm. The optical projection lens can effectively correct various aberrations of the optical projection lens by combining the lenses with positive focal power and negative focal power and setting the refractive index, the Abbe number and the thickness of each lens in a proper range, thereby achieving the optical effects of high image quality and small distortion, and ensuring smaller volume and better imaging quality.

Description

Optical projection lens and display system

Technical Field

The application relates to the field of optical imaging, in particular to an optical projection lens and a display system.

Background

The optical waveguide AR near-eye display system mainly comprises two optical components, one is a light engine for providing amplified display images, and comprises a display device and a projection optical lens with an amplifying function; the other is a waveguide device for transmitting the image beam, and the waveguide device is provided with a grating for coupling in the image beam (coupling-in grating), a grating for expanding the pupil (expanding pupil grating), and a grating for coupling out the image beam (coupling-out grating). In some waveguide-type augmented reality display devices, the waveguide device has only an incoupling grating and an outcoupling grating, and the outcoupling grating has the functions of expanding the pupil and outcoupling the image beam at the same time.

The projection optical lens is used for amplifying an image source displayed by the micro display device, forming a virtual image at a certain distance and imaging on a retina through the optical waveguide device.

The existing optical projection lens is difficult to ensure to have smaller volume and better imaging quality at the same time.

SUMMERY OF THE UTILITY MODEL

The main objective of the present application is to provide an optical projection lens and a display system, so as to solve the problem that the optical projection lens in the prior art is difficult to ensure that the optical projection lens has a smaller volume and better imaging quality.

In order to achieve the above object, according to one aspect of the present application, there is provided an optical projection lens including six lenses, and a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens in order from an object side to an image side, wherein the first lens has a negative refractive power, the second lens has a positive refractive power, the third lens has a positive refractive power, the fourth lens has a negative refractive power, the fifth lens has a negative refractive power, the sixth lens has a positive refractive power, a refractive index of each of the lenses is between 1.8 and 2.0, an abbe number of each of the lenses is between 15 and 50, and a thickness of each of the lenses is between 0.5 and 1.5 mm.

Further, the focal length f1 of the first lens satisfies: f1 is more than or equal to minus 35mm and less than or equal to minus 10 mm; the focal length f2 of the second lens satisfies: f2 is more than or equal to 5mm and less than or equal to 20 mm; the focal length f3 of the third lens satisfies: f3 is more than or equal to 5mm and less than or equal to 20 mm; the focal length f4 of the fourth lens satisfies: f4 is more than or equal to minus 20mm and less than or equal to minus 5 mm; the focal length f5 of the fifth lens satisfies: f5 is more than or equal to minus 30mm and less than or equal to minus 10 mm; the focal length f6 of the sixth lens satisfies: f6 is more than or equal to 5mm and less than or equal to 20 mm.

Further, the refractive index n1 of the first lens satisfies: n1 is more than or equal to 1.9 and less than or equal to 2.0; the refractive index n2 of the second lens satisfies: n2 is more than or equal to 1.8 and less than or equal to 1.9; the refractive index n3 of the third lens satisfies: n3 is more than or equal to 1.8 and less than or equal to 1.9; the refractive index n4 of the fourth lens satisfies: n4 is more than or equal to 1.9 and less than or equal to 2.0; the refractive index n5 of the fifth lens meets the condition that n5 is more than or equal to 1.9 and less than or equal to 2.0; the refractive index n6 of the sixth lens satisfies: n6 is more than or equal to 1.8 and less than or equal to 1.9.

Further, the abbe number v1 of the first lens satisfies: v1 is more than or equal to 17 and less than or equal to 35; the abbe number v2 of the second lens satisfies: v2 is more than or equal to 35 and less than or equal to 50; the abbe number v3 of the third lens satisfies: v3 is more than or equal to 35 and less than or equal to 50; abbe number v4 of the fourth lens: v4 is more than or equal to 17 and less than or equal to 35; the abbe number v5 of the fifth lens satisfies: v5 is more than or equal to 17 and less than or equal to 35; the abbe number v6 of the sixth lens satisfies: v6 is more than or equal to 35 and less than or equal to 50.

Further, the thickness T1 of the first lens satisfies: t1 is more than or equal to 0.8mm and less than or equal to 1.5 mm; the thickness T2 of the second lens satisfies: t2 is more than or equal to 0.8mm and less than or equal to 1.5 mm; the thickness T3 of the third lens satisfies: t3 is more than or equal to 0.8mm and less than or equal to 1.5 mm; the thickness T4 of the fourth lens satisfies: t4 is more than or equal to 0.5mm and less than or equal to 1.0 mm; the thickness T5 of the fifth lens satisfies: t3 is more than or equal to 0.8mm and less than or equal to 1.5 mm; the thickness T6 of the sixth lens satisfies: t6 is more than or equal to 0.8mm and less than or equal to 1.5 mm.

Further, the surface of each lens is a spherical surface.

Further, the optical projection lens further comprises at least one antireflection film, and one antireflection film is arranged on one surface of one lens.

Further, the optical projection lens further comprises an aperture diaphragm, and the aperture diaphragm is located on one side, far away from the fifth lens, of the sixth lens.

Further, the optical path corresponding to the optical projection lens is an image-side telecentric optical path.

According to another aspect of the present application, there is provided a display system including a display unit and an optical projection lens on a side of the display unit, the optical projection lens being any one of the optical projection lenses.

By applying the technical scheme of the application, the optical projection lens comprises six lenses, and a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens are sequentially arranged from an object side to an image side, wherein the first lens, the fourth lens and the fifth lens have negative focal power, the second lens, the third lens and the sixth lens have positive focal power, the refractive index of each lens is 1.8-2.0, the Abbe number of each lens is 15-50, and the thickness of each lens is 0.5-1.5 mm. The optical projection lens can effectively correct various aberrations of the optical projection lens by combining the lenses with positive focal power and negative focal power and setting the refractive index, the Abbe number and the thickness of each lens in a proper range, thereby achieving the optical effects of high image quality and small distortion, and ensuring smaller volume and better imaging quality.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application. In the drawings:

FIG. 1 shows a schematic view of a display system of an embodiment of the present application;

FIG. 2 shows a modulation transfer function curve of an optical projection lens in an embodiment of the present application;

FIGS. 3(a) and 3(b) show field curvature and distortion curves, respectively, of an optical projection lens in an embodiment of the present application;

fig. 4 illustrates an optical waveguide near-eye display device in an embodiment of the present application.

Wherein the figures include the following reference numerals:

10. a display unit; 20. a first lens; 30. a second lens; 40. a third lens; 50. a fourth lens; 60. a fifth lens; 70. a sixth lens; 80. an aperture diaphragm; 90. an optical projection lens; 100. an optical waveguide device.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. Also, in the specification and claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element or "connected" to the other element through a third element.

As described in the background of the invention, it is difficult to ensure a smaller volume and better imaging quality of the optical projection lens in the prior art, and in order to solve the above problems, the present application provides an optical projection lens and a display system.

In an exemplary embodiment of the present application, an optical projection lens is provided, which includes six lenses, as shown in fig. 1, a first lens 20, a second lens 30, a third lens 40, a fourth lens 50, a fifth lens 60, and a sixth lens 70 in order from an object side to an image side, wherein the first lens 20 has a negative refractive power, the second lens 30 has a positive refractive power, the third lens 40 has a positive refractive power, the fourth lens 50 has a negative refractive power, the fifth lens 60 has a negative refractive power, the sixth lens 70 has a positive refractive power, a refractive index of each of the lenses is between 1.8 and 2.0, an abbe number of each of the lenses is between 15 and 50, and a thickness of each of the lenses is between 0.5 and 1.5 mm.

The optical projection lens comprises six lenses, namely a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from an object side to an image side, wherein the first lens, the fourth lens and the fifth lens have negative focal power, the second lens, the third lens and the sixth lens have positive focal power, the refractive index of each lens is 1.8-2.0, the Abbe number of each lens is 15-50, and the thickness of each lens is 0.5-1.5 mm. The optical projection lens can effectively correct various aberrations of the optical projection lens by combining the lenses with positive focal power and negative focal power and setting the refractive index, the Abbe number and the thickness of each lens in a proper range, thereby achieving the optical effects of high image quality and small distortion, and ensuring smaller volume and better imaging quality.

In an embodiment of the present application, the focal length f1 of the first lens satisfies: f1 is more than or equal to minus 35mm and less than or equal to minus 10 mm; the focal length f2 of the second lens satisfies: f2 is more than or equal to 5mm and less than or equal to 20 mm; the focal length f3 of the third lens satisfies: f3 is more than or equal to 5mm and less than or equal to 20 mm; the focal length f4 of the fourth lens satisfies: f4 is more than or equal to minus 20mm and less than or equal to minus 5 mm; the focal length f5 of the fifth lens satisfies: f5 is more than or equal to minus 30mm and less than or equal to minus 10 mm; the focal length f6 of the sixth lens satisfies: f6 is more than or equal to 5mm and less than or equal to 20 mm. By controlling the focal length of each lens, the object side end can have enough convergence capacity to adjust the focusing position of the light beam, so that the optical total length of the optical projection lens is shortened, and the volume of the optical projection lens is further reduced.

In order to reduce the generation of spherical aberration and chromatic dispersion of the optical projection lens, thereby ensuring that the optical projection lens has better imaging quality, in another embodiment of the present application, the refractive index n1 of the first lens satisfies: n1 is more than or equal to 1.9 and less than or equal to 2.0; the refractive index n2 of the second lens satisfies: n2 is more than or equal to 1.8 and less than or equal to 1.9; the refractive index n3 of the third lens satisfies: n3 is more than or equal to 1.8 and less than or equal to 1.9; the refractive index n4 of the fourth lens satisfies: n4 is more than or equal to 1.9 and less than or equal to 2.0; the refractive index n5 of the fifth lens meets the condition that n5 is more than or equal to 1.9 and less than or equal to 2.0; the refractive index n6 of the sixth lens satisfies: n6 is more than or equal to 1.8 and less than or equal to 1.9.

In another embodiment of the present application, the abbe number v1 of the first lens satisfies: v1 is more than or equal to 17 and less than or equal to 35; the abbe number v2 of the second lens satisfies: v2 is more than or equal to 35 and less than or equal to 50; the abbe number v3 of the third lens satisfies: v3 is more than or equal to 35 and less than or equal to 50; abbe number v4 of the fourth lens: v4 is more than or equal to 17 and less than or equal to 35; the abbe number v5 of the fifth lens satisfies: v5 is more than or equal to 17 and less than or equal to 35; the abbe number v6 of the sixth lens satisfies: v6 is more than or equal to 35 and less than or equal to 50. In the embodiment, the abbe number of each lens is set in a corresponding range, so that the generation of spherical aberration and chromatic dispersion of the optical projection lens can be further reduced, and better imaging quality is further ensured.

In still another embodiment of the present application, the thickness T1 of the first lens satisfies: t1 is more than or equal to 0.8mm and less than or equal to 1.5 mm; the thickness T2 of the second lens satisfies: t2 is more than or equal to 0.8mm and less than or equal to 1.5 mm; the thickness T3 of the third lens satisfies: t3 is more than or equal to 0.8mm and less than or equal to 1.5 mm; the thickness T4 of the fourth lens satisfies: t4 is more than or equal to 0.5mm and less than or equal to 1.0 mm; the thickness T5 of the fifth lens satisfies: t3 is more than or equal to 0.8mm and less than or equal to 1.5 mm; the thickness T6 of the sixth lens satisfies: t6 is more than or equal to 0.8mm and less than or equal to 1.5 mm. Each of the above lenses satisfies each of the above conditional expressions, which contributes to uniform lens size distribution, good workability, securing assembly stability, and contributes to aberration of the entire optical projection lens, further shortening the optical total length of the entire optical projection lens.

In another embodiment of the present application, the surface of each of the lenses is a spherical surface. The spherical lens is low in processing difficulty and cost, and the spherical lens is used in the embodiment, so that the processing difficulty is reduced, and the cost is reduced.

Specifically, in each of the above lenses, not only a spherical design is used, but also at least one optical surface may be designed to have an aspherical surface or a free-form surface.

In an embodiment of the present application, each of the lenses is made of an optical glass material. Compared with optical plastics, the optical glass has better thermal stability. Because the display device can emit more heat in the working process, the focal power and the surface type of the optical plastic lens can be influenced, and the optical glass lens has good thermal stability, so that the surface type and the focal power of the optical glass lens are not easy to change, and the optical performance stability of the optical projection lens can be ensured.

In another embodiment of the present application, the optical projection lens further includes at least one antireflection film, and one of the antireflection films is disposed on one surface of one of the lenses. The anti-reflection film is arranged on the surface of the lens, so that the light transmittance can be improved, the light efficiency of the optical lens can be improved, and the imaging effect of the optical projection lens can be improved.

In yet another embodiment of the present application, as shown in fig. 1, the optical projection lens further includes an aperture stop 80, and the aperture stop 80 is located on a side of the sixth lens 70 away from the fifth lens 60. The aperture diaphragm can control the energy, resolution and contrast of the optical projection lens, and can eliminate stray light and correct off-axis aberration of the optical projection lens.

In another embodiment of the present application, the optical path corresponding to the optical projection lens is an image-side telecentric optical path. And (4) image space telecentric design, namely, the incidence angles of the principal rays with different field angles to the surface of the display device are all zero. The image space telecentric optical path design of the optical projection lens can maximally utilize the light energy in the vertical emergent direction, can improve the light energy utilization rate of the optical lens, further improve the image brightness of the near-to-eye display equipment, and further ensure that the imaging effect of the optical projection lens is better.

According to another aspect of the present application, there is provided a display system, as shown in fig. 1, including a display unit 10 and an optical projection lens located at one side of the display unit 10, the optical projection lens being any one of the optical projection lenses described above.

The optical projection lens of the application can effectively correct various aberrations of the optical projection lens by combining the lenses with positive focal power and negative focal power and setting the refractive index, the Abbe number and the thickness of each lens in a proper range, thereby achieving the optical effects of high image quality and small distortion and ensuring smaller volume and better imaging quality. The display unit may be a Micro-LED (Micro light emitting diode) or a Micro-OLED (Micro organic light emitting diode) or other display device.

In order to make the technical solutions of the present application more clearly understood by those skilled in the art, the technical solutions of the present application will be described in detail below with reference to specific examples and comparative examples.

Examples

This embodiment provides an optical projection lens, as shown in fig. 1, including six lenses, in order from an object side to an image side, a first lens 20, a second lens 30, a third lens 40, a fourth lens 50, a fifth lens 60, and a sixth lens 70, and an aperture stop. The focal length f of the projection lens is 6.4mm, the field angle FOV is 28 degrees, the aperture of the aperture diaphragm 80 is 4mm, the maximum aperture of the optical lens is 6mm, and the total length of the optical projection lens is 12 mm. The total length of the optical projection lens means a distance from the display device to the aperture stop 80. The parameter information of each of the above lenses is as follows:

lens barrel	Focal length (mm)	Thickness (mm)	Refractive index	Abbe number
					First lens	-31	1.0	1.96	17.5
Second lens	7.6	1.0	1.82	46.5
					Third lens	8.6	1.0	1.82	46.5
Fourth lens	-8.3	0.5	1.96	17.5
					Fifth lens element	-15.5	1.0	1.96	17.5
Sixth lens element	7.8	1.0	1.82	46.5

As can be seen from the above table, the focal length f1 of the first lens 20 is-31 mm, the thickness T1 is 1.0mm, the refractive index is 1.96, and the Abbe number is 17.5; the focal length f2 of the second lens 30 is 7.6mm, the thickness T2 is 1.0mm, the refractive index is 1.82, and the Abbe number is 46.5; the focal length f3 of the third lens 40 is 8.6mm, the thickness T3 is 1.0mm, the refractive index is 1.82, and the Abbe number is 46.5; the focal length f4 of the fourth lens 50 is-8.3 mm, the thickness T4 is 0.5mm, the refractive index is 1.96, and the Abbe number is 17.5; the focal length f5 of the fifth lens 60 is-15.5 mm, the thickness T5 is 1.0mm, the refractive index is 1.96, and the Abbe number is 17.5; the sixth lens 70 has a focal length f6 of 7.8mm, a thickness T6 of 1.0mm, a refractive index of 1.82, and an Abbe number of 46.5.

Fig. 2 is a modulation transfer function curve of the optical projection lens in the above embodiment. The modulation transfer function reflects the resolving power of the optical projection lens, is used for evaluating the imaging quality of the optical projection lens, and can embody the restoring capability of the optical projection lens to the details of the object. The abscissa is spatial resolution, the unit is a line logarithm per millimeter (lp/mm), and the higher the spatial resolution is, the larger the corresponding MTF value is, which indicates that the higher the resolving power of the optical projection lens is, the better the imaging quality is. As can be seen from FIG. 2, the MTF values of the optical projection lens at 125lp/mm spatial resolution are all greater than 0.4, and the optical projection lens has high resolving power.

Fig. 3(a) and 3(b) are field curvature and distortion curves of the optical projection lens, respectively. As can be seen from the two drawings of fig. 3, the optical distortion of the optical projection lens is less than 0.15%, which indicates that the distortion of the projected image is small.

Fig. 4 is an optical waveguide near-eye display device employing the above-described optical projection lens. The light emitted from the display unit 10 passes through the optical projection lens 90, then enters the optical waveguide device 100, is transmitted through the optical waveguide, then exits at the near-to-eye position of the optical waveguide, and finally enters the human eye for imaging.

From the above description, it can be seen that the above-described embodiments of the present application achieve the following technical effects:

the optical projection lens comprises six lenses, namely a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from an object side to an image side, wherein the first lens, the fourth lens and the fifth lens have negative focal power, the second lens, the third lens and the sixth lens have positive focal power, the refractive index of each lens is 1.8-2.0, the Abbe number of each lens is 15-50, and the thickness of each lens is 0.5-1.5 mm. The optical projection lens can effectively correct various aberrations of the optical projection lens by combining the lenses with positive focal power and negative focal power and setting the refractive index, the Abbe number and the thickness of each lens in a proper range, thereby achieving the optical effects of high image quality and small distortion, and ensuring smaller volume and better imaging quality. 2) The display system comprises a display unit and an optical projection lens positioned on one side of the display unit, wherein the optical projection lens is any one of the optical projection lenses, the optical projection lens is combined by a lens with positive focal power and negative focal power, and the refractive index, the Abbe number and the thickness of each lens are set in a proper range, so that various aberrations of the optical projection lens can be effectively corrected, the optical effect of high image quality and small distortion is achieved, and the optical projection lens simultaneously has small volume and good imaging quality.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (10)

1. An optical projection lens is characterized by comprising six lenses, namely a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from an object side to an image side, wherein the first lens has negative focal power, the second lens has positive focal power, the third lens has positive focal power, the fourth lens has negative focal power, the fifth lens has negative focal power, the sixth lens has positive focal power, the refractive index of each lens is 1.8-2.0, the Abbe number of each lens is 15-50, and the thickness of each lens is 0.5-1.5 mm.

2. The optical projection lens of claim 1 wherein the focal length f1 of the first lens satisfies: f1 is more than or equal to minus 35mm and less than or equal to minus 10 mm; the focal length f2 of the second lens satisfies: f2 is more than or equal to 5mm and less than or equal to 20 mm; the focal length f3 of the third lens satisfies: f3 is more than or equal to 5mm and less than or equal to 20 mm; the focal length f4 of the fourth lens satisfies: f4 is more than or equal to minus 20mm and less than or equal to minus 5 mm; the focal length f5 of the fifth lens satisfies: f5 is more than or equal to minus 30mm and less than or equal to minus 10 mm; the focal length f6 of the sixth lens satisfies: f6 is more than or equal to 5mm and less than or equal to 20 mm.

3. The optical projection lens as claimed in claim 1, wherein the refractive index n1 of the first lens satisfies: n1 is more than or equal to 1.9 and less than or equal to 2.0; the refractive index n2 of the second lens satisfies: n2 is more than or equal to 1.8 and less than or equal to 1.9; the refractive index n3 of the third lens satisfies: n3 is more than or equal to 1.8 and less than or equal to 1.9; the refractive index n4 of the fourth lens satisfies: n4 is more than or equal to 1.9 and less than or equal to 2.0; the refractive index n5 of the fifth lens meets the condition that n5 is more than or equal to 1.9 and less than or equal to 2.0; the refractive index n6 of the sixth lens satisfies: n6 is more than or equal to 1.8 and less than or equal to 1.9.

4. An optical projection lens as claimed in claim 1, characterized in that the abbe number v1 of the first lens satisfies: v1 is more than or equal to 17 and less than or equal to 35; the abbe number v2 of the second lens satisfies: v2 is more than or equal to 35 and less than or equal to 50; the abbe number v3 of the third lens satisfies: v3 is more than or equal to 35 and less than or equal to 50; abbe number v4 of the fourth lens: v4 is more than or equal to 17 and less than or equal to 35; the abbe number v5 of the fifth lens satisfies: v5 is more than or equal to 17 and less than or equal to 35; the abbe number v6 of the sixth lens satisfies: v6 is more than or equal to 35 and less than or equal to 50.

5. The optical projection lens of claim 1 wherein the thickness T1 of the first lens satisfies: t1 is more than or equal to 0.8mm and less than or equal to 1.5 mm; the thickness T2 of the second lens satisfies: t2 is more than or equal to 0.8mm and less than or equal to 1.5 mm; the thickness T3 of the third lens satisfies: t3 is more than or equal to 0.8mm and less than or equal to 1.5 mm; the thickness T4 of the fourth lens satisfies: t4 is more than or equal to 0.5mm and less than or equal to 1.0 mm; the thickness T5 of the fifth lens satisfies: t3 is more than or equal to 0.8mm and less than or equal to 1.5 mm; the thickness T6 of the sixth lens satisfies: t6 is more than or equal to 0.8mm and less than or equal to 1.5 mm.

6. The optical projection lens of any of claims 1 to 5 wherein the surface of each lens is spherical.

7. The optical projection lens as claimed in any one of claims 1 to 5, further comprising at least one antireflection film, one antireflection film being provided on one surface of one of the lenses.

8. The optical projection lens of any of claims 1 to 5 further comprising an aperture stop located on a side of the sixth lens away from the fifth lens.

9. The optical projection lens as claimed in claim 8, wherein the optical path corresponding to the optical projection lens is an image-side telecentric optical path.

10. A display system comprising a display unit and an optical projection lens on one side of the display unit, characterized in that the optical projection lens is an optical projection lens according to any one of claims 1 to 9.

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