CN219936209U

CN219936209U - Low-stray light far vision display device

Info

Publication number: CN219936209U
Application number: CN202321699558.4U
Authority: CN
Inventors: 程德文; 孙佳平; 王其为
Original assignee: Beijing Ned+ Ar Display Technology Co ltd; Future Optics Shangrao Research Institute Co ltd
Current assignee: Beijing Ned+ Ar Display Technology Co ltd; Future Optics Shangrao Research Institute Co ltd
Priority date: 2023-06-30
Filing date: 2023-06-30
Publication date: 2023-10-31
Anticipated expiration: 2033-06-30

Abstract

The utility model provides a low-stray light far-viewing display device, which comprises a display component for providing an image source and an optical system with an amplifying effect on the image source provided by the display component, wherein the optical system at least comprises a curved surface reflecting mirror and a spectroscope, wherein a beam light element for controlling the light emitting angle of the image source is arranged in or on a light emitting surface of the display component; the light emitting side of the display component is provided with an anti-glare layer; the spectroscope adopts a low-transmittance design; through the various improvements, the parasitic light in the HUD optical system is controlled, and various parasitic lights possibly occurring in the HUD optical system are eliminated. Compared with the prior art, the far-view display device has the advantages of low stray light, low cost and high imaging quality.

Description

Low-stray light far vision display device

Technical Field

The present utility model relates to a remote vision display device, and more particularly, to a desktop remote vision display device.

Background

Currently, many applications provide an electronic display to present digital information to a viewer, and Head-up displays (HUDs) project digital information on a built-in display screen directly in front of the human eye by the principle of optical refraction and reflection, free from the limitation that the viewer must face a physical screen, and are currently widely used in the field of aircrafts and automobiles.

The realization of heads-up display technology requires a relatively small display image source and an optical system with a projection amplifying function, and therefore has the advantage of throwing away an image itself, that is, when a user views an image provided by a heads-up display system, the image is projected by the optical system to be emitted from a far place, and eyes of the user are in a relatively relaxed state when viewing, so that myopia caused by long-term near viewing is not induced.

With the development and application of current technologies, HUD optical systems are widely used in the fields of vision protection and control due to their long virtual image distance, for example, a desktop type far vision display device which is being developed by the present inventors is a typical application of vision protection and control. However, the inventor finds that the existing HUD optical system generally has the problems of obvious stray light and serious influence on the look and feel in the research and development process.

Disclosure of Invention

The utility model aims to provide a low-stray-light far-vision display device so as to improve the human eye appearance.

A low-stray light tele-vision display device includes a display assembly for providing an image source and an optical system having a magnifying effect on the image source, wherein,

the display module is characterized in that a light beam element is arranged in the display module or on the light emitting surface, and the light beam element controls the light emitting angle of the image source to be not more than +/-50 degrees at maximum and not less than +/-5 degrees at minimum; an anti-glare layer is attached to the outermost surface of the display component;

the optical system at least comprises a spectroscope and a curved surface reflecting mirror, and the transmittance of the spectroscope to a visible light wave band is not more than 35%; light emitted by the display source is directed to the spectroscope, then the light is transmitted to the curved surface reflector under the reflection action of the spectroscope, and the light is reflected back to the spectroscope again at the curved surface reflector and transmitted, and finally reaches the exit pupil position;

the exit pupil distance of the optical system is 150-600 mm, and the virtual image distance is 3-8 m.

Preferably, the light-beam element is an ultra-fine shutter structure provided in the interior or light-emitting side of the display assembly.

Alternatively, preferably, the beam light element is a microlens array disposed in the light emitting direction of the display assembly.

Preferably, the haze value of the anti-dazzle layer is between 3 and 30 percent, and the roughness is between 0.03 and 1 um.

Preferably, the display assembly is between 4 inches and 20 inches in size.

Preferably, the reflectivity of the curved reflector is between 80% and 100%.

Preferably, the optical system is provided with a positive lens or a lens group having positive optical power between the display assembly and the beam splitter.

Preferably, the beam splitter is at an angle of 30-70 degrees to the display assembly.

Preferably, the surface of the beam splitter is a plane or a curved surface concave to the curved reflector.

Preferably, a beam splitting film is plated on one side of the beam splitter facing the curved surface reflector and the display source, and the reflectivity of the beam splitting film ranges from 10% to 50%; an antireflection film is attached to one side of the spectroscope facing the exit pupil position.

According to the low-stray-light far-viewing display device provided by the utility model, the light beam element for controlling the light emitting angle of the image source is arranged in the display assembly or on the light emitting surface, the anti-dazzle layer is attached to the outermost surface of the display assembly, and the spectroscope with low transmittance to the visible light wave band is used, so that the stray light of the whole HUD optical system is controlled, and various stray lights possibly occurring in the HUD optical system are eliminated. Compared with the prior art, the far-view display device has the advantages of low stray light, low cost and high imaging quality.

Drawings

FIGS. 1a-1d are schematic optical path diagrams of four parasitic lights present in a HUD optical system, respectively, in the prior art;

fig. 2 is a HUD optical system incorporating an ultra-fine shutter structure and an anti-glare layer;

fig. 3 is a HUD optical system incorporating a microlens array and an antiglare layer.

Detailed Description

The utility model will be explained in detail below with reference to the drawings and specific embodiments.

As shown in fig. 1a-1d, the HUD optical system at least includes a display component 101, a beam splitter 102 and a curved mirror 103, where the light emitted from the display component 101 is directed to the beam splitter 102, and then the light is reflected by the beam splitter 102 and transmitted to the curved mirror 103, where the light is reflected back to the beam splitter 103 again and transmitted, finally reaches an exit pupil position, and enters a human eye to image.

The stray light paths in the similar HUD optical systems are mainly four: 1. light emitted by the display source 101 sequentially passes through the spectroscope 102 and the curved surface reflecting mirror 103, then reaches the spectroscope 102, is reflected again by the spectroscope 102, and then is transmitted to the light of the outermost surface of the display component 101, and is secondarily transmitted by the light path formed after being reflected again by the outermost surface of the display component 101 (see fig. 1 a); 2. the large-angle light emitted by the display source 101 irradiates the curved reflector 103, and sequentially passes through the curved reflector 103, the spectroscope 102 and the curved reflector 103 to be reflected, and then irradiates the human eye 104 through the spectroscope 102 to form the large-light-emitting angle stray light of the display source (see fig. 1 b); 3. external light 105 enters the optical structure through the spectroscope 102, and after encountering the curved reflector 103, the light is reflected by the curved reflector 103 and then transmitted to the spectroscope 102, and finally enters the human eye 104 to form direct-transmission stray light (see fig. 1 c); 4. after the external light 105 is reflected on the two side surfaces of the beam splitter 102, the light is transmitted back to the human eye 104 to form external reflection stray light (see fig. 1 d). The imaging of these types of stray light in the imaging system is inconsistent with the depth of the virtual image formed by the normal imaging light path, so that the user can have difficulty in focusing eyeballs when using optical equipment with the types of stray light, thereby causing vision health problems.

The utility model provides various optical means to correspondingly inhibit and eliminate various stray lights of the HUD optical system. A desktop remote display device using the HUD optical system will be described as an example.

The far vision display device comprises a display image source and an optical system with an amplifying function on an image provided by the display image source, wherein a beam light element for controlling the light emitting angle of the image source is arranged in or on the light emitting surface of the display image source, and the function of the optical system is to regulate or inhibit a light beam with a large divergence angle emitted by the display source, so that the light emitting angle of the display source to the optical system is not more than +/-50 degrees and not less than +/-5 degrees at the maximum, and the possible stray light with the large light emitting angle of the display source in the amplifying process of the optical system is eliminated while the normal imaging of the optical system is ensured, and the optical system corresponds to the second stray light shown in fig. 1 b.

The optical system of the tele-vision display device comprises at least a beam splitter 102 and a curved mirror 103. Wherein the beam splitter 102 is close to a window or is used as a window of a remote display device, the window is covered by a light-transmitting material, typically optical glass or resin material, facing the user, so that the user sees the image light emitted from the display image source through the window; such an optical system may be conveniently housed in an integral housing with the window being part of the outer surface of the housing.

According to different design purposes of the remote vision display device, the optical system of the remote vision display device can further comprise a positive lens, and the remote vision amplification effect can be realized by adjusting optical parameters of the positive lens, the spectroscope and the curved reflector.

The far vision display device provided by the utility model is slightly different from a C-HUB optical system applied to vehicles such as automobiles, airplanes and the like. The display image sources used therein are small in size, preferably less than 20 inches, for example, 4 to 15.6 inches of display image sources may be selected. The optical system is configured such that non-parallel light is incident on the human eye, and the user can see through the viewing window light that is significantly enlarged, such as from a remote location, compared to the size of the image displayed by the display image source, to form a virtual image. The virtual image forms a predetermined field of view FOV for the human eye, calculated as a diagonal field of view, typically between 10 degrees and 40 degrees. The virtual image distance of the far vision display device is about 3 m-8 m, and the exit pupil distance is 150 mm-600 mm.

First embodiment

Fig. 2 is a view showing a HUD optical system incorporating an ultra-fine shutter structure and an antiglare layer according to the present utility model, wherein the ultra-fine shutter structure is used as a beam element.

The HUD optical system includes an LCD display assembly 201, a positive lens 202, a dichroic mirror 203, a curved mirror 204, and an eye 205 in the exit pupil position. The light emitted by the LCD display assembly 201 is converged to the beam splitter 203 after passing through the positive lens 202, then the light is reflected by the beam splitter 203 and transmitted to the curved mirror 204, and the light is reflected again at the curved mirror 204, and is reversely transmitted back to the beam splitter 203 and transmitted, and finally enters the human eye 205.

In this embodiment, the LCD display assembly 201 is composed of a backlight module 2011, a micro shutter (micro) structure 2012, a liquid crystal panel (OpenCell) 2013, and an Anti-glare (AG) layer 2014. The range of the light emitting angle of the LCD display assembly 201 is not more than ±50 degrees, and the minimum is not less than ±5 degrees under the effect of the ultra fine shutter.

The beam element used in this embodiment is an ultra-fine shutter structure 2012, and the principle of the beam element is that the ultra-fine shutter structure 2012 shields the light emitted from the backlight module 201 at a large angle and transmits the light emitted from the backlight module at a small angle. By the structure, the divergence angle of the whole display can be adjusted, and stray light with a large divergence angle of a display source of the HUD optical system is eliminated. The light transmission angle of the ultra-fine shutter structure 2012 is not more than ±50 degrees, and the minimum is not less than ±5 degrees.

Preferably, the thickness of the ultra-fine louver structure 2012 is 0.1mm to 2mm.

Alternatively, the ultra-fine shutter structure 2012 may be disposed between the liquid crystal panel (OpenCell) 2013 and the AG layer 2014 to achieve the same parasitic light suppression effect.

In other embodiments, not shown, the display assembly may also use an OLED display, and by setting an ultra-fine shutter structure on the light-emitting surface of the OLED display, the light-emitting angle range of the image source may be limited, so as to achieve the purpose of eliminating stray light with a large divergence angle of the display source of the HUD optical system.

In the far-view display device provided in this embodiment, other parasitic lights in the HUD optical system are also eliminated.

The AG layer 2014 is disposed on the outermost side of the entire display source and functions to diffusely reflect light transmitted to the surface. The AG layer 2014 reduces the intensity of the reflected light from the beam splitter 203 reflected by the display source 201 in the path of the light path secondary transmission stray light by reducing the specular reflectivity of the outermost surface of the screen, thereby greatly reducing the light path secondary transmission stray light of the HUD system according to the present utility model and eliminating the stray light corresponding to fig. 1 a.

Optionally, the AG layer 2014 has a haze value of 3% -30% and a roughness of 0.03 um-1 um.

The surface of the positive lens 202, which is close to the display screen 201, is S1, the surface of the positive lens, which is close to the spectroscope 203, is S2, and optical anti-reflection films are attached to the surface S1 and the surface S2. The thickness of the positive lens is between 10mm and 50mm.

The positive lens may use a single lens or a lens group having positive optical power composed of a plurality of lenses.

The spectroscope 203 is a planar glass, one side close to the curved surface reflecting mirror 204 is plated with an optical spectroscope, and the reflectivity range is between 10% and 50%. An Anti-reflection (AR) film is attached to the side near the human eye 205, and absorption of the base material and antireflection of the optical surface can greatly reduce external reflection type stray light of the HUD optical system in the present utility model, which corresponds to the stray light in fig. 1 d.

Optionally, the thickness of the spectroscope is between 1mm and 5 mm.

In addition, the spectroscope 203 has absorptivity before the plating of the spectroscope film, that is, besides the transmittance of the whole spectroscope to the visible light wave band is reduced due to the reflection of the spectroscope film, the glass itself or an absorption layer is additionally arranged on the glass to enable the glass to have a certain gray level, the transmittance of the spectroscope 203 is reduced, and the transmittance of the whole spectroscope 203 to the visible light wave band is not more than 35%. The low transmittance of the beam splitter 203 can attenuate the direct-transmitting parasitic light of the HUD system of the present utility model, corresponding to the parasitic light in fig. 1 c.

Optionally, the material of the beam splitter 203 may be optical resin, and the optical antireflection film near the side of the human eye 205 may be omitted.

Alternatively, the beam splitter 203 may use a concave mirror that is concave to the curved mirror 204, thereby improving the imaging quality.

The curved surface reflector 204 is a concave surface reflector facing the exit pupil position, the surface is plated with an optical film, and the reflectivity of the visible light wave band is 80-100%. Alternatively, the reflecting surface of the curved mirror 204 may be spherical, aspherical, or free-form for better imaging. In the tele-display device, the radius of curvature of the curved mirror 204 should be greater than 150mm in size.

Table 1 shows the optical design parameters of the optical elements in the novel low-parasitic HUD optical structure according to the first embodiment.

TABLE 1 optical design parameters for optical elements in Low parasitic HUD optical structures

Surface of the body	Type(s)	Radius of curvature	Thickness of (L)	Refractive index	Abbe number
						Exit pupil	Spherical surface	Infinite number of cases	225
Spectroscope 203	Spherical surface	Infinite number of cases	3	1.5168	64.16
						Curved mirror 204	Spherical surface	-460
Positive lens surface S1	Spherical surface	-900	27	1.5168	64.16
						Positive lens surface S2	Spherical surface	197.45

Second embodiment

Fig. 3 is a novel HUD optical system of the present utility model by introducing a microlens array and an antiglare layer, comprising a display assembly 301, a positive lens 302, a beam splitter 303, a curved mirror 304, and a human eye 305 at the exit pupil position. The light emitted by the display component 301 is converged to the beam splitter 303 after passing through the positive lens 302, then the light is reflected to the curved reflector 304, and the light is reflected again at the curved reflector 304, reversely propagates back to the beam splitter 303 and is transmitted, and finally enters the human eye 305.

The display module 301 is constituted by an image display source 3011, a first microlens array 3012, a second microlens array 3013, a protective glass 3014, and an AG (anti-glare) layer 3015. Among them, the image display source 3011, the first microlens array 3012, the second microlens array 3013, the protective glass 3014, and the AG (anti-glare) layer 3015 may be packaged together to constitute the integrated display assembly 301.

Alternatively, the image display source 3011 may be a display such as an LCD, OLED, or the like, with a display area size of between 4 and 20 inches.

The display assembly 301 has a small divergence angle, specifically, the final light emitting angle of the display assembly 301 is not more than ±50 degrees, and the minimum is not less than ±5 degrees. In this embodiment, the beam light elements are a first microlens array 3012 and a second microlens array 3013, and the principle of implementation is that the outgoing light of the image display source 3101 is modulated by the first microlens array 3012 and the second microlens array 3013 so that the light is emitted at a small angle. Modulation of the display source exit ray angle by the first and second microlens arrays 3012 and 3013 can eliminate the large divergence angle parasitic light of the HUD optical system corresponding to the display source of fig. 1 b.

The surface of the first microlens array 3012 on the side close to the image display source 3011 is S11, and the surface on the side close to the second microlens 3013 is S12. The second microlens array 3013 has a surface S21 on the side close to the first microlens array 3012 and a surface S22 on the side close to the cover glass 3014.

The array period of the first microlens array 3012 and the second microlens array 3013 is between 0.1mm and 3 mm. The array size of the first microlens array 3012 and the second microlens array 3013 ranges from 4 to 20 inches. Alternatively, the number of microlens arrays may be adjusted.

Alternatively, the two microlens arrays may employ the same optical parameters.

In this embodiment, the structure of the beam element is described by taking two microlens arrays disposed opposite to each other as an example. It will be appreciated that the two microlens arrays described above can be implemented using other forms of microlens arrays, and that the parameters of each microlens can be adjusted according to design requirements. Here, the light emission angle control of the display image using the microlens array will be described, and the specific implementation form of the microlens array is not limited.

The AG layer 3015 is disposed at the outermost side of the entire display module 301, and causes diffuse reflection of light transmitted from the outside to the surface. The AG layer 3015 reduces the intensity of reflected light from the beam splitter 303 reflected via the display screen 301 in the path of light path secondary transmission stray light by reducing the specular reflectivity of the outermost surface of the screen, thereby greatly reducing the path secondary transmission stray light in fig. 1a of the HUD optical system.

Optionally, the AG layer 3015 has a haze value of 3% -30% and a roughness of 0.03 um-1 um.

The positive lens 302 is S31 on the side close to the display component 301, S32 on the side close to the spectroscope 303, and optical antireflection films are attached to both the S31 surface and the S32 surface. The optical parameters of the positive lens in this embodiment are close to those of the first embodiment.

The spectroscope 303 is planar glass, one side close to the curved surface reflecting mirror 304 is plated with an optical spectroscope, and the reflectivity range is between 10% and 55%. An optical antireflection film is attached to the side near the human eye 305, and absorption by the base material and antireflection by the optical surface can greatly reduce the external reflection stray light shown in fig. 1d of the HUD optical system.

Optionally, the thickness of the spectroscope is between 1mm and 5 mm.

Meanwhile, besides the reduction of the overall transmittance of the spectroscope to visible light caused by the reflection of the spectroscope, the glass has a certain gray level by itself or an absorption layer is additionally arranged on the glass, so that the absorption rate of the spectroscope can be improved, and the overall transmittance of the spectroscope 303 to the visible light wave band is not more than 35%. The low transmittance of the beam splitter 303 reduces the direct-transmitted parasitic light shown in fig. 1c of the HUD system of the present utility model.

Optionally, the material of the beam splitter 303 may be optical resin, and the optical antireflection film near the side of the human eye 305 may be omitted.

The curved reflector 304 is a concave reflector, the surface of which is coated with an optical film, and the reflectivity of the visible light wave band ranges from 80% to 100%.

Alternatively, in order to achieve a better imaging effect, the reflecting surface of the curved mirror may be spherical, aspherical or free-form.

Table 2 shows the optical design parameters of the optical elements in the novel low-parasitic HUD optical structure according to the second embodiment.

TABLE 2 optical design parameters for optical elements in Low parasitic HUD optical structures

The foregoing description is only of the preferred embodiments of the present utility model, and is not intended to limit the scope of the present utility model. This utility model may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the utility model to those skilled in the art. In addition, the features of the embodiments may be combined in other ways than those described above, and the combined technical solutions still fall within the scope of the present utility model.

Claims

1. A low-stray light tele-vision display device comprising a display assembly for providing an image source and an optical system having a magnifying effect on the image source, characterized in that:

the display device comprises a display assembly, wherein a light emitting surface or an inner part of the display assembly is provided with a light beam element, and the light beam element is used for controlling the light emitting angle of an image source to be not more than +/-50 degrees and not less than +/-5 degrees at the maximum; an anti-glare layer is attached to the outermost surface of the display component;

2. The low-stray light distance vision display of claim 1, wherein:

the light-beam element is an ultra-fine shutter structure provided in the interior or light-exit side of the display assembly.

3. The low-stray light distance vision display of claim 1, wherein:

the beam light element is a microlens array arranged in the light emitting direction of the display assembly.

4. A low parasitic light distance display device as claimed in any one of claims 1-3, wherein:

the haze value of the anti-dazzle layer is between 3 and 30 percent, and the roughness is between 0.03 and 1 um.

5. The low-stray light distance vision display of claim 1, wherein:

the display assembly is between 4 inches and 20 inches in size.

6. The low-stray light distance vision display of claim 1, wherein:

the reflectivity of the curved reflector is 80% -100%.

7. The low-stray light distance vision display of claim 1, wherein:

the optical system is provided with a positive lens or a lens group having positive optical power between the display element and the spectroscope.

8. The low-stray light distance vision display of claim 1, wherein:

the angle between the spectroscope and the display component is 30-70 degrees.

9. The low-stray light distance vision display of claim 1, wherein:

the surface type of the spectroscope is a plane or a curved surface concave to the curved surface reflecting mirror.

10. A low parasitic light distance display device as claimed in any one of claims 1-3, wherein:

one side of the spectroscope facing the curved surface reflecting mirror and the display source is plated with a light-splitting film, and the reflectivity range of the light-splitting film is between 10% and 50%; an antireflection film is attached to one side of the spectroscope facing the exit pupil position.