CN112764227A - Near-to-eye display system - Google Patents

Abstract

The embodiment of the present invention relates to the technical field of projection display, and discloses a near-eye display system, which includes an image display unit for emitting a light beam containing image information, and a waveguide plate and a focus adjustment that are sequentially arranged in the light emitting direction of the image display unit The focusing unit includes two Alvarez lenses, which are used to adjust the imaging position of the light beam. The near-eye display system provided by the embodiment of the present invention is provided with two Alvarez lenses on the light-emitting side of the waveguide sheet. The focal unit can adjust the diopter of the real environment and the image at the same time, and can meet more people without affecting the difference between the real environment and the image, and the system volume is small.

Description

A near-eye display system

technical field

Embodiments of the present invention relate to the technical field of projection display, and in particular, to a near-eye display system.

Background technique

Near-eye display system, also known as helmet-mounted display, originally originated in the field of the Air Force, mainly to solve the problem of pilots facing the increasing amount of information collected by precision instruments and weapon systems on the aircraft. All the information of the instrument is presented in the field of view in front of the pilot, allowing the pilot to concentrate on operating the aircraft and aiming. With the maturity and popularization of technology, the near-eye display system is also widely used in the civilian field. Because it has the characteristics of overlapping some of the added information or images with the real environment and can exist in the same space and time, it is widely used. It is widely used in the fields of fire protection, education, advertising, information retrieval and design interaction.

In the process of implementing the embodiments of the present invention, the inventor found that there are at least the following problems in the above related technologies: with the popularization of civilian use and the complexity of the crowd, for example, the diopter of the eyes of different users is different, and the applicability of the product becomes a problem. The new challenge is that due to the limited space between the eye and the display system in the near-eye display system, it has become a design problem to increase the focus unit while taking into account the miniaturization of the system.

SUMMARY OF THE INVENTION

In view of the above-mentioned defects of the prior art, the purpose of the embodiments of the present invention is to provide a focus-adjustable and miniaturized near-eye display system.

The purpose of the embodiment of the present invention is achieved through the following technical solutions:

In order to solve the above technical problems, an embodiment of the present invention provides a near-eye display system, including:

an image display unit for emitting a light beam containing image information;

a waveguide sheet, which is arranged in the light-emitting direction of the image display unit, and is used for transmitting the light beam;

The focusing unit includes two Alvarez lenses, the focusing unit is arranged in the light-emitting direction of the waveguide sheet, and is used to adjust the imaging position of the light beam.

In some embodiments, it also includes:

A driving unit connected to the focusing unit and configured to be able to move at least any one of the two Alvarez lenses to change the relative displacement of the two Alvarez lenses, thereby adjusting all the Alvarez lenses the focal length of the focusing unit.

In some embodiments, the focal length of the focusing unit satisfies the following relationship:

φ _x,y =A _x x ³ +A _x yx ² +A _y y ³ +A _y xy ² +Bx ² +Cxy+Dy ² +Ex+Fy+G

Among them, φ _{x, y} represents the focal length of the focusing unit, (x, y) represents the relative displacement of the two Alvarez lenses in the Ex and Ey directions, Ex and Ey are perpendicular to the The curved surface of the Alvarez lens and the two directions perpendicular to each other, (A, B, C, D, E, F, G) are the focal length of the focusing unit and the two Alvarez Cubic fit constant for the relative displacement of the lens.

In some embodiments, both of the two Alvarez lenses include a rectangular plane and a free-form surface disposed opposite to each other, and the rectangular planes of the two Alvarez lenses are disposed adjacent to each other.

In some embodiments, the two Alvarez lenses are arranged centrally symmetrically.

In some embodiments, the image display unit includes:

an image source for emitting the light beam containing image information;

An opto-mechanical amplifying module, which is arranged between the image source and the waveguide sheet, is used for amplifying the light beam.

In some embodiments, when the image source is a reflective image source, the image display unit further includes an illumination module, which is composed of light emitting diodes and at least one collimating lens, diffractive device, microlens array and/or diffusing sheet .

In some embodiments, the system further includes:

a degree input unit, which is connected with the focusing unit and is used for acquiring the degree of myopia or hyperopia input by the user,

The focusing unit is further configured to be able to determine the target focal length of the focusing unit according to the degree of nearsightedness or farsightedness input by the user, and adjust the relative displacement of the two Alvarez lenses according to the target focal length .

In some embodiments, the system further includes:

a human eye position detection unit, which is connected to the focusing unit and is used for detecting the position information of the human eye,

The focusing unit is further configured to be able to determine the target focal length of the focusing unit according to the position information of the human eye and adjust the relative displacement of the two Alvarez lenses according to the target focal length.

In some embodiments, the system further includes:

An adjustment knob, which is connected to the focusing unit, is used for receiving a user's gesture action, and adjusting the relative displacement of the two Alvarez lenses according to the user's gesture action.

Compared with the prior art, the beneficial effects of the present invention are: different from the prior art, a near-eye display system is provided in the embodiment of the present invention, which includes an image display unit for emitting a light beam containing image information, and a waveguide sheet and a focusing unit sequentially arranged in the light-emitting direction of the image display unit, the focusing unit includes two Alvarez lenses for adjusting the imaging position of the light beam, the near-eye display system provided by the embodiment of the present invention A focusing unit consisting of two Alvarez lenses is arranged on the light-emitting side of the waveguide sheet, which can adjust the diopter of the real environment and the image at the same time, and can meet more requirements without affecting the difference between the real environment and the image. crowd, and the system is small in size.

Description of drawings

One or more embodiments are exemplified by pictures in the corresponding drawings, and these exemplifications do not constitute a limitation on the embodiments, and elements/modules with the same reference numerals in the drawings are represented as similar elements/modules, unless otherwise stated, the figures in the accompanying drawings do not constitute a scale limitation.

1 is a schematic structural diagram of a near-eye display system provided by an embodiment of the present invention;

2 is another schematic structural diagram of a near-eye display system provided by an embodiment of the present invention;

3 is a schematic diagram of a specific structure of an example of a near-eye display system provided by an embodiment of the present invention;

Fig. 4 is a partial enlarged schematic view of the waveguide sheet and the focusing unit in the near-eye display system shown in Fig. 3;

FIG. 5 is a schematic diagram of the three-dimensional structure of the waveguide sheet and the focusing unit shown in FIG. 4;

FIG. 6 is a schematic diagram of an optical path of the near-eye display system shown in FIG. 3 .

Detailed ways

The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application will be described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

It should be noted that, if there is no conflict, various features in the embodiments of the present invention may be combined with each other, which are all within the protection scope of the present application. In addition, although the functional modules are divided in the schematic diagram of the device, in some cases, the modules may be divided differently from the device.

In order to facilitate the definition of the connection structure, the present invention uses the transmission direction of the light beam as a reference to define the position of the components.

Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the technical field of the present invention. The terms used in the description of the present invention in this specification are only for the purpose of describing specific embodiments, and are not used to limit the present invention. As used in this specification, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

Specifically, the embodiments of the present invention are further described below with reference to the accompanying drawings.

An embodiment of the present invention provides a near-eye display system. Please refer to FIG. 1, which shows a structure of a near-eye display system provided by an embodiment of the present invention. As shown in FIG. 1, the near-eye display system 100 includes: an image The display unit 101 , the waveguide sheet 201 and the focusing unit 301 . The image display unit 101 is used to emit light beams containing image information; the waveguide sheet 201 is arranged in the light output direction of the image display unit 101 and used to transmit the light beams; the focusing unit 301 includes Two Alvarez lenses, the focusing unit 301 is arranged on the light-emitting direction of the waveguide sheet 201, and is used to adjust the imaging position of the light beam. The embodiment of the present invention utilizes an Alvarezlens to implement a compact zoom system to adjust the imaging diopter, reduce the volume of the focusing unit, and has a wider focusing range and simpler adjustment method.

Further, please refer to FIG. 2 together, which shows another structure of a near-eye display system provided by an embodiment of the present invention. The near-eye display system may further include: a driving unit 401 , which is connected with the focusing unit 301 connected and configured to be able to move at least any one of the two Alvarez lenses to change the relative displacement of the two Alvarez lenses, so as to adjust the focal length of the focusing unit 301 . The driving unit 401 may include a controller and a driving motor, wherein the controller is a chip or module with computing capability, which can calculate the relative displacement of the two Alvarez lenses according to the focal length of the focusing unit 301, or , the focal length of the focusing unit 301 is calculated according to the relative displacement of the two Alvarez lenses; the drive motor is used to move at least one of the two Alvarez lenses according to the control instructions issued by the controller any piece.

The Alvarez lens is composed of one or two cubic surfaces, wherein the focal length of the focusing unit 301 satisfies the following relationship:

φ _x,y =A _x x ³ +A _x yx ² +A _y y ³ +A _y xy ² +Bx ² +Cxy+Dy ² +Ex+Fy+G

Wherein, φ _{x, y} represents the focal length of the focusing unit 301, and (x, y) represents the two Alvarez lenses in the Ex and Ey directions (refer to the focus adjustment shown in FIG. 5 below). The relative displacement on the three-dimensional structure of the unit), Ex and Ey are two directions perpendicular to the curved surface of the Alvarez lens and perpendicular to each other, (A, B, C, D, E, F, G) are The cubic fitting constant of the focal length of the focusing unit 301 and the relative displacement of the two Alvarez lenses.

Specifically, if analyzed from a one-position angle, assuming that only the two Alvarez lenses are controlled to move in the Ex direction, and the relative displacement in the Ey direction is set to 0, the focal length calculation formula of the focusing unit 301 can be simplified. is the following relation:

φ _x =A _x x ³ +Bx ² +Ex+G

It is not difficult to see that the focal length φ _x of the focusing unit 301 has a cubic function relationship with the relative displacement x, so when displacement occurs in the Ex direction, the focal length φ _x of the focusing unit 301 will change accordingly, Thereby the adjustment of the diopter in the Ex direction is achieved. Similarly, for the three-dimensional space, the displacement in the Ex and Ey directions can be adjusted to different diopter, so that the system can be applied to more people.

Further, please continue to refer to FIG. 2 , the image display unit 101 includes: an image source 110 and an opto-mechanical amplifying module 120 . in,

The image source 110 is used to emit the light beam containing image information; the image source 110 is one of LCD, OLED, LCOS, DM, and Micro-LED, and when the image source 110 is reflective such as LCOS When an image source is used, the image display unit 101 further includes an illumination module, which is composed of a light emitting diode (LED) and at least one collimating lens, a diffractive device, a microlens array and/or a diffusing sheet, wherein the light emitting diode (LED) ( LED) can be any one of monochromatic light or polychromatic light; the at least one collimating lens is a spherical lens, an aspherical lens and/or a Fresnel lens; the diffraction device is a blazed grating, a surface relief grating, a holographic lens Any one of a lens or a volume grating; the microarray lens is a fly-eye lens or a cylindrical lens; the diffusing sheet is a diffusing sheet or a diffusing sheet (Diffuser).

The opto-mechanical amplifying module 120 is disposed between the image source 110 and the waveguide sheet 201 for amplifying the light beam. The optical-mechanical amplifying unit 120 is composed of a polarization beam splitter (PBS, Polarization Beam Splitter) and at least one spherical lens, wherein the polarization beam splitter has polarization characteristics and can be any one of grid type or coating; the Spherical lenses include concave-convex, plano-concave, plano-convex and convex lenses, and the material can be either glass or resin.

The waveguide sheet 201 may be one of a geometric array optical waveguide sheet and a grating waveguide sheet.

Further, in order to determine the target focal length to which the focusing unit 310 needs to be adjusted, to determine the relative displacement of the two Alvarez lenses in the focusing unit to be adjusted, so as to adjust the diopter suitable for the user , on the one hand, it can be that after the user inputs its diopter information, the focusing unit 301 automatically adjusts according to the input diopter data; Even retinal devices can be used to automatically adjust the focal length, which is usually more suitable for people without myopia; in addition, a physical adjustable knob can also be provided, and the user wears the near-eye display system when using it. For near-eye display devices, users can adjust the focal length according to their own needs, such as adjusting the focal length through the clarity of the image, until the image clarity meets the user's needs.

Further, please continue to refer to FIG. 2, the system further includes: a degree input unit 501, which is connected to the focusing unit 301 and is used to obtain the degree of myopia or hyperopia input by the user, and the focusing unit 301 is further configured as The target focal length of the focusing unit 301 can be determined according to the degree of nearsightedness or farsightedness input by the user, and the relative displacement of the two Alvarez lenses can be adjusted according to the target focal length. Specifically, the device or system may be provided with a physical button and/or a touch screen, and the user can input his or her nearsightedness or farsightedness degree through the physical button or the virtual button on the touch screen, or input through a microphone voice, etc. Specifically, The degree input unit 501 can be set according to actual needs.

Further, please continue to refer to FIG. 2, the system further includes: a human eye position detection unit 601, which is connected to the focusing unit 301 and is used for detecting the position information of the human eye, and the focusing unit 301 is also configured with In order to be able to determine the target focal length of the focusing unit 301 according to the position information of the human eye, and adjust the relative displacement of the two Alvarez lenses according to the target focal length. Specifically, the detection of the position of the human eye can be realized by detecting the position of the user's human eye/pupil retina in combination with a distance sensor and a ranging algorithm. For example, the position of the pupil is determined by using the image collected by the camera. Actually, the human eye position detection unit 601 needs to be set.

Further, please continue to refer to FIG. 2, the adjustment knob 701, which is connected to the focusing unit 301, is used to receive the user's gesture action, and adjust the two Alvarez lenses according to the user's gesture action Relative displacement. Specifically, the adjustment knob 701 can be configured to rotate/move the adjustment knob 701 , correspondingly, the relative displacement of the Alvarez lens can be adjusted to realize the adjustment of the focal length.

It should be noted that one of the above methods, or several methods can be set at the same time to determine the target focal length of the focusing unit 310 to realize applications in different scenarios. A capable human eye position detection unit 601, and an adjustment knob 701 or a degree input unit 501 that can be manually adjusted by the user, so that users with normal vision can automatically adjust, and users with certain vision problems can adjust as needed.

Specifically, please refer to FIG. 3 , FIG. 4 and FIG. 5 together, wherein FIG. 3 shows a specific structure of an example of a near-eye display system provided by an embodiment of the present invention, and FIG. 4 is the near-eye display system shown in FIG. 3 . A partial enlarged view of the middle waveguide sheet and the focusing unit, FIG. 5 is a three-dimensional structural diagram of the waveguide sheet and the focusing unit shown in FIG. 4 .

In the example shown in FIG. 3 , a reflective image source is used as an example. Therefore, the image display unit 101 is provided with an illumination module, and the illumination module uses a light-emitting diode (LED) as the illumination light source 111 . A Fresnel lens 112, a diffraction grating 113, a microarray lens 114, a scattering sheet 115 and a polarizing beam splitting prism 123 are arranged in sequence on the upper surface of the beam. Reflective image source 121 . In the embodiment of the present invention, the image source 121 adopts a liquid crystal on silicon (Lcos, Liquid Crystal on Silicon) as the image source, and a first lens 122, a polarizing beam splitting prism 123, and a second lens 124 are sequentially arranged in the light emitting direction of the image source 121 , the third lens 125 , the fourth lens 126 and the waveguide sheet 201 . A focusing unit 301 is provided on the light-emitting side of the waveguide sheet 201 , wherein, as shown in FIG. 3 , FIG. 4 and FIG. 5 , the focusing unit 301 includes two Alvarez lenses, and the two The Alvarez lenses all include a rectangular plane and a free-form surface arranged oppositely, and the rectangular planes of the two Alvarez lenses are arranged adjacent to each other. And yes, the two Alvarez lenses are arranged symmetrically in the center.

When the near-eye display system 100 provided by the embodiment of the present invention works, please refer to FIG. 6 , which shows the optical path of the near-eye display system shown in FIG. 3 . The light (S light) generated by the illumination light source 111 passes through the Fresnel lens 112 , the diffraction grating 113 , the microarray lens 114 , and the diffuser 115 to generate uniform illumination light. After the uniform illumination light enters the polarization beam splitter prism 123, due to the polarization characteristics of the polarization beam splitter prism 123 to the polarized light, the illumination light (S light) is reflected to the image source 121 after passing through a 45-degree slope, and the modulated S light changes. In order to reflect the P light to the first lens 122 , after entering the polarizing beam splitter prism, the P light directly enters the second lens 124 , passes through the third lens 125 and the fourth lens 126 for beam shaping and amplification, and is coupled to the waveguide sheet 201 . The total reflection is performed in the waveguide sheet 201, and when it passes through a series of slopes with certain transmittance and reflectivity, the reflected light enters the focusing unit 301, the transmitted light continues to propagate, and then the reflected light passes through the next slope and is then reflected to The focusing unit 301 transmits and reflects in sequence, so that the reflected light has a pupil dilation effect in the transmission direction of the waveguide sheet 201 , and can evenly reflect the image to the focusing unit 301 through a certain transmissive and refracted reflective surface. The focusing unit 301 adjusts the diopter through the Alvarez lens to realize the adjustment of different focal lengths, so that the image can be imaged more clearly on the retina, and finally suitable for more people.

An embodiment of the present invention provides a near-eye display system, which includes an image display unit for emitting a light beam containing image information, a waveguide sheet and a focusing unit sequentially arranged in the light-emitting direction of the image display unit, and the focusing unit It includes two Alvarez lenses for adjusting the imaging position of the light beam. The near-eye display system provided by the embodiment of the present invention is provided with a focusing unit consisting of two Alvarez lenses on the light-emitting side of the waveguide sheet, which can make The diopter adjustment of the real environment and the image is performed at the same time, which can satisfy more people without affecting the difference between the real environment and the image, and the system volume is small.

It should be noted that the device embodiments described above are only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physically separated unit, that is, it can be located in one place, or it can be distributed over multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; under the idea of the present invention, the technical features in the above embodiments or different embodiments can also be combined, The steps may be carried out in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity; although the invention has been The skilled person should understand that it is still possible to modify the technical solutions recorded in the foregoing embodiments, or to perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the implementation of the present invention. scope of technical solutions.

Claims (10)

1. A near-eye display system, comprising:

an image display unit for emitting a light beam containing image information;

a waveguide sheet disposed in a light exit direction of the image display unit for transmitting the light beam;

and the focusing unit comprises two Alvarez lenses, is arranged in the light outgoing direction of the waveguide sheet and is used for adjusting the imaging position of the light beam.

2. The near-eye display system of claim 1 further comprising:

and a driving unit connected with the focusing unit and configured to be capable of moving at least any one of the two Alvarez lenses to change the relative displacement of the two Alvarez lenses, thereby adjusting the focal length of the focusing unit.

3. The near-eye display system of claim 2 wherein the focal length of the focusing unit satisfies the following relationship:

φ_x,y＝A_xx³+A_xyx²+A_yy³+A_yxy²+Bx²+Cxy+Dy²+Ex+Fy+G

wherein phi is_x,yThe focal length of the focusing unit is represented, the relative displacement amounts of the two Alvarez lenses in the Ex direction and the Ey direction are represented, the Ex direction and the Ey direction are perpendicular to the curved surface of the Alvarez lens and perpendicular to each other, and the A, B, C, D, E, F and G are cubic fitting constants of the focal length of the focusing unit and the relative displacement amount of the two Alvarez lenses.

4. The near-eye display system of claim 3,

the two Alvarez lenses comprise a rectangular plane and a free-form surface which are arranged oppositely, and the rectangular planes of the two Alvarez lenses are arranged adjacently.

5. The near-eye display system of claim 4,

the two Alvarez lenses are arranged in a central symmetry mode.

6. The near-eye display system of claim 5 wherein the image display unit comprises:

the image source is used for emitting the light beam containing the image information;

and the optical machine amplification module is arranged between the image source and the waveguide sheet and is used for amplifying the light beam.

7. The near-eye display system of claim 6,

when the image source is a reflective image source, the image display unit further comprises an illumination module which is composed of a light emitting diode, at least one collimating lens, a diffraction device, a micro-lens array and/or a scattering sheet.

8. The near-eye display system of any one of claims 2-7 wherein the system further comprises:

a degree input unit connected with the focusing unit for acquiring near-sighted or far-sighted degrees input by a user,

the focusing unit is also configured to determine a target focal length of the focusing unit according to the near-vision or far-vision degrees input by the user and adjust the relative displacement of the two Alvarez lenses according to the target focal length.

9. The near-eye display system of any one of claims 2-7 wherein the system further comprises:

a human eye position detection unit connected with the focusing unit and used for detecting the position information of the human eyes,

the focusing unit is also configured to be capable of determining a target focal length of the focusing unit according to the position information of the human eyes and adjusting the relative displacement of the two Alvarez lenses according to the target focal length.

10. The near-eye display system of any one of claims 2-7 wherein the system further comprises:

and the adjusting knob is connected with the focusing unit and used for receiving the gesture action of a user and adjusting the relative displacement of the two Alvarez lenses according to the gesture action of the user.

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