CN114879290A - Diffusion sheet and head-up display device - Google Patents
Diffusion sheet and head-up display device Download PDFInfo
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- CN114879290A CN114879290A CN202210521927.4A CN202210521927A CN114879290A CN 114879290 A CN114879290 A CN 114879290A CN 202210521927 A CN202210521927 A CN 202210521927A CN 114879290 A CN114879290 A CN 114879290A
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- 238000009792 diffusion process Methods 0.000 title claims abstract description 84
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- 238000009826 distribution Methods 0.000 description 6
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- 230000004424 eye movement Effects 0.000 description 2
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/02—Diffusing elements; Afocal elements
- G02B5/0205—Diffusing elements; Afocal elements characterised by the diffusing properties
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/01—Head-up displays
- G02B27/0101—Head-up displays characterised by optical features
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B3/00—Simple or compound lenses
- G02B3/0006—Arrays
- G02B3/0012—Arrays characterised by the manufacturing method
- G02B3/0031—Replication or moulding, e.g. hot embossing, UV-casting, injection moulding
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B3/00—Simple or compound lenses
- G02B3/0006—Arrays
- G02B3/0037—Arrays characterized by the distribution or form of lenses
- G02B3/0062—Stacked lens arrays, i.e. refractive surfaces arranged in at least two planes, without structurally separate optical elements in-between
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- G—PHYSICS
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- G02B3/00—Simple or compound lenses
- G02B3/02—Simple or compound lenses with non-spherical faces
- G02B3/08—Simple or compound lenses with non-spherical faces with discontinuous faces, e.g. Fresnel lens
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/02—Diffusing elements; Afocal elements
- G02B5/0268—Diffusing elements; Afocal elements characterized by the fabrication or manufacturing method
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- G—PHYSICS
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- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/01—Head-up displays
- G02B27/0179—Display position adjusting means not related to the information to be displayed
- G02B2027/0183—Adaptation to parameters characterising the motion of the vehicle
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/01—Head-up displays
- G02B2027/0192—Supplementary details
- G02B2027/0196—Supplementary details having transparent supporting structure for display mounting, e.g. to a window or a windshield
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Abstract
The invention provides a diffusion sheet and a head-up display device. The diffusion sheet includes: the micro-structure comprises a tooth surface which takes a Fresnel lens layer as a base body, and a plurality of concave or convex micro-lenses are arranged on the base body and arranged in an array to form a micro-lens array area. The invention solves the problem that the diffusion sheet in the prior art occupies large space.
Description
Technical Field
The invention relates to the technical field of optical display equipment, in particular to a diffusion sheet and head-up display equipment.
Background
The HUD, Head Up Display Head-Up Display, appeared on fighters at first, was tried on in automobiles in the last 80 th century, and is a device which utilizes the optical principle to project virtual images of driving information such as vehicle speed and navigation in the direction of a front windshield. The main purpose of this device is to reduce the driver's head-down viewing of the instrument panel or navigation, etc., and to maintain his line of sight on the road, so as to improve the driving safety.
Generally speaking, the HUD optical path system mainly comprises an image source display module and a reflective imaging module, wherein the image source display module includes a projection light machine, a diffusion sheet, a projection adjusting mirror, and the like. Image information displayed by the image source PGU is magnified by reflection of plane or curved mirrors (folding mirrors and rotatable mirrors), and finally reflected to an eye movement area of a driver, i.e., an eye movement range or eye box (Eyebox), through a windshield. Currently, display technologies applied to the HUD projector mainly include LCD projection, DLP projection, laser scanning projection, LCOS projection, and the like.
In the laser scanning projection display technology, an image modulator in a projection light machine is a scanning galvanometer, and a diffusion sheet serving as a light diffusion device is arranged on a downstream light path of the scanning galvanometer. The light output from the coherent light source, which is intensity or wavelength (color) modulated in time series, is irradiated onto the scanning galvanometer, which emits it at different angles corresponding to the time series of light source modulation, thereby forming a spatial light distribution corresponding to the target image. Next, light is irradiated onto a diffusion sheet, which diffuses the light corresponding to each pixel into a distributed light field having a certain divergence angle.
The common diffusion sheet is mainly composed of concave or convex micro-lenses arrayed at a certain period or randomly. When light enters the diffusion sheet at a larger angle, emergent light is deflected, and an illumination area after being emitted by the diffusion sheet deviates from the center of an illuminated surface along with the increase of the incident angle, so that the efficiency of a view field window and the uniformity of illumination are reduced. Therefore, if the light path collimation is performed on the light incident side of the diffusion sheet in advance, the above problem can be effectively avoided. At present, conventional solutions in the industry, such as a collimating element, such as a fresnel lens, which is arranged in front of a diffusion sheet, or a microstructure is arranged on both sides of the diffusion sheet, that is, a fresnel lens structure is realized on a light incident surface of the diffusion sheet, but this will enlarge the structural space occupied by the diffusion sheet, and increase the production cost and the process difficulty.
That is, the diffusion sheet of the related art has a problem of occupying a large space.
Disclosure of Invention
The invention mainly aims to provide a diffusion sheet and a head-up display device, and aims to solve the problem that the diffusion sheet in the prior art occupies a large space.
In order to achieve the above object, according to one aspect of the present invention, there is provided a diffusion sheet including: the Fresnel lens comprises a light incident surface and a light emergent surface, wherein one of the light incident surface and the light emergent surface is provided with a microstructure, the microstructure comprises a tooth surface which takes a Fresnel lens layer as a base body, and a plurality of concave or convex micro lenses are arranged on the base body and arranged in an array manner to form a micro lens array area.
Further, the surface of the micro lens is a curved surface, and the curved surface includes one of a spherical surface, a quadratic surface, a polynomial surface, and a free-form surface.
Further, the surfaces of the microlenses are arrayed in the normal direction of the tooth surface or the central axis direction of the fresnel lens layer.
Further, the polynomial surface satisfies:
wherein,
for each location point (x) of the microlens 0 ，y 0 ) Corresponding height value of curved surface, c j Is polynomial coefficient, and m and n are polynomial power exponent.
Further, a plurality of micro lenses are set to be distributed on the oxy plane in a periodic or random array mode, and the central coordinate point of each micro lens is set to be F i (a i ，b i ) For a coordinate point P (x, y) on the oxy plane, the center of the coordinate point P is taken as the center of a circle, and the radius is taken as the radius
Has a plurality of points F within a circular area i And simultaneously satisfies the following conditions: i x-a i |≤l/2，|y-b i L is not less than w/2, i is not less than 0 and not more than N, wherein l and w are respectively the length and width of the microlens, and N is a point F i The number of the cells.
Further, a plurality of dots F i The curved surface of the corresponding micro lens satisfies the following conditions:
further, when the microlens is convex, the surface of the microlens array region formed by the plurality of microlenses having a convex shape satisfies:
or when the micro-lens is concave, the surface of the micro-lens array area formed by the concave multiple micro-lenses satisfies:
further, the tooth surface on which the fresnel lens layer is provided is represented as
When the surfaces of the micro lenses are arrayed along the central axis direction of the Fresnel lens layer, the formed surfaces of the micro structures meet the requirement
Furthermore, the shape of the light incident surface or the light emergent surface is quadrilateral, the length of the quadrilateral is more than or equal to 20mm and less than or equal to 200mm, and the width of the quadrilateral is more than or equal to 20mm and less than or equal to 200 mm.
According to another aspect of the present invention, there is provided a head-up display apparatus including the above diffusion sheet; the projection light machine is positioned on one side of the diffusion sheet; and the reflecting element is used for receiving the image light emitted by the projector after passing through the diffusion sheet and reflecting the image light to a specified position for displaying.
By applying the technical scheme of the invention, the diffusion sheet comprises a light inlet surface and a light outlet surface, wherein one of the light inlet surface and the light outlet surface is provided with a microstructure, the microstructure comprises a tooth surface of a Fresnel lens layer as a base body, a plurality of concave or convex micro lenses are arranged on the base body, and the plurality of micro lenses are arranged in an array to form a micro lens array area.
The utility model provides a diffusion piece is through setting up the microlens array district on the flank of tooth on fresnel lens layer, unites two into one the flank of tooth and the surface that microlens array district formed, can enough guarantee fresnel lens layer itself to the collimation effect of light, can satisfy the diffusion effect of microlens array district to light again, can satisfy the basic function demand of light collimation and light diffusion, is favorable to improving the window efficiency and the illuminance homogeneity of light visual field under the different incident angles. Through setting up the microlens array area on one side surface on single fresnel lens layer, accessible single grey level photoetching, impression process are makeed the processing, are favorable to processing convenience, greatly reduced manufacturing cost and technology degree of difficulty, have improved production efficiency. Simultaneously, this application adopts the mode of setting up the overlap of microlens array area on the flank of tooth on fresnel lens layer, but not the mode that sets up one deck microlens array layer in addition, make the appearance of microlens array area combine the appearance of flank of tooth, avoided additionally increasing the condition of collimation component, the component has been saved, the cost is saved, the whole thickness of diffusion piece has been compressed greatly simultaneously, be favorable to guaranteeing frivolousization and the miniaturization of diffusion piece, the occupation space of diffusion piece has been saved greatly, be more convenient for use diffusion piece in the less equipment of size.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
FIG. 1 is a schematic view showing a structure of a diffusion sheet according to an alternative embodiment of the present invention;
FIG. 2 shows a schematic view of another angle of the diffuser plate of FIG. 1;
FIG. 3 is a schematic view showing a structure of a diffusion sheet according to an alternative embodiment of the present invention;
FIG. 4 shows a schematic view of the diffuser plate of FIG. 3 configured with convex microlenses;
FIG. 5 is a schematic diagram showing an optical path when the surface of a microlens having a convex shape is a light-emitting surface;
FIG. 6 is a schematic diagram of an optical path when the surface of a convex microlens is a light incident surface;
FIG. 7 is a schematic view showing a structure of a diffusion sheet according to an alternative embodiment of the present invention;
FIG. 8 shows a schematic side view of a concave-shaped microlens of the diffuser of FIG. 7;
FIG. 9 is a schematic diagram showing an optical path when a concave microlens is used as a light-emitting surface;
FIG. 10 is a schematic diagram of an optical path when a concave microlens is used as a light incident surface;
FIG. 11 is a graph showing a transmitted light intensity distribution of a diffusion sheet of the present invention;
FIG. 12 shows a pattern of spots at different angles of incidence for a diffuser of the present invention;
FIG. 13 shows a distribution diagram of individual microlenses in a microlens array region of an embodiment of the present application.
Wherein the figures include the following reference numerals:
11. a main body portion; 12. a cyclic structure; 121. a tooth surface; 13. a microlens array region; 14. a normal line; 15. a central axis.
Detailed Description
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.
It is noted that, unless otherwise indicated, 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.
In the present invention, unless specified to the contrary, use of the terms of orientation such as "upper, lower, top, bottom" or the like, generally refer to the orientation as shown in the drawings, or to the component itself in a vertical, perpendicular, or gravitational orientation; likewise, for ease of understanding and description, "inner and outer" refer to the inner and outer relative to the profile of the components themselves, but the above directional words are not intended to limit the invention.
The invention provides a diffusion sheet and a head-up display device, aiming at solving the problem that the diffusion sheet in the prior art occupies a large space.
As shown in fig. 1 to 13, the diffusion sheet includes a light incident surface and a light emergent surface, one of the light incident surface and the light emergent surface is provided with a microstructure, the microstructure includes a tooth surface 121 of a fresnel lens layer as a base, and a plurality of concave or convex microlenses are arranged on the base, and the plurality of microlenses are arranged in an array to form a microlens array region 13.
The utility model provides a diffusion piece is through setting up microlens array district 13 on the flank of tooth 121 on fresnel lens layer, unite two into one the surface that flank of tooth 121 and microlens array district 13 formed, can enough guarantee fresnel lens layer itself to the collimation effect of light, can satisfy the diffusion effect of microlens array district 13 to light again, can satisfy the basic function demand of light collimation and light diffusion, be favorable to improving the window efficiency and the illuminance homogeneity of light visual field under the different incident angles. Through setting up microlens array area 13 on one side surface on single fresnel lens layer, accessible single grey level photoetching, impression process are makeed the processing, are favorable to processing convenience, greatly reduced manufacturing cost and technology degree of difficulty, have improved production efficiency. Simultaneously, this application adopts the mode of setting up microlens array area 13 stack on the flank of tooth 121 on fresnel lens layer, but not the mode that sets up one deck microlens array layer in addition, make the appearance of microlens array area 13 combine the appearance of flank of tooth 121, the condition of additionally increasing collimating element has been avoided, the component has been saved, the cost is saved, simultaneously, the whole thickness of diffusion piece has been compressed greatly, be favorable to guaranteeing the frivolousization and the miniaturization of diffusion piece, the occupation space of diffusion piece has been saved greatly, be more convenient for use diffusion piece in the less equipment of size.
It should be noted that, the fresnel lens layer of the above-mentioned diffusion sheet includes a main body portion 11 and a plurality of annular structures 12 disposed on one side surface of the main body portion 11, the plurality of annular structures 12 are concentrically disposed, and two adjacent annular structures 12 are disposed at an interval or sequentially disposed, a cross section of the annular structure 12 is in a tooth shape, a side surface of the annular structure 12 away from the main body portion 11 is a tooth surface 121, a microlens array area 13 is disposed on the tooth surface 121, and the tooth surface 121 is covered by the microlens array area 13, that is, an area of the tooth surface 121 is equal to an area of the microlens array area 13.
As shown in fig. 5 and 9, a side surface of each microlens away from the body portion 11 is convex or concave. The tooth surface 121 of the annular structure 12 of the Fresnel lens layer is used as a main body surface type, so that incident light with different angles can be deflected in a light path, and the collimation or approximate collimation effect on light is realized; and a plurality of convex or concave microlenses are arranged on the annular structure 12, so that the convex or concave surfaces of the microlenses can further deflect the light, and the function of performing equidirectional or cross diffusion on the light is achieved.
Specifically, the surface of one side of each microlens far away from the main body portion 11 is a curved surface, and the curved surface includes one of a spherical surface, a quadratic surface, a polynomial surface, and a free-form surface. And a plurality of microlenses are arrayed in the direction of the normal 14 of the tooth surface 121 or the direction of the central axis 15 of the fresnel lens layer. The light distribution requirements of different target specifications can be met by adjusting the curved surface structure design of the micro lens; according to different array modes of a plurality of micro lenses on the annular structure 12, the micro lenses can be distributed along the normal 14 of each tooth surface 121 or along the central axis 15 of the Fresnel lens layer, and the uniform diffusion shaping of incident light can be realized. Preferably, the plurality of microlenses are arranged in a projective array overlapping along the central axis 15 direction of the fresnel lens layer, that is, the height values of the curved surfaces at each position point are overlapped, so that the performance index of the diffusion sheet is better.
As shown in fig. 1, 3 and 7, one side surface of the fresnel lens layer having the annular structure 12 is a quadrangle, the length of the quadrangle is greater than or equal to 20mm and less than or equal to 200mm, and the width of the quadrangle is greater than or equal to 20mm and less than or equal to 200 mm. The quadrilateral may be a rectangle or a square, preferably a square. That is, the diffusion sheet has a structure size in the range of 20mm × 20mm to 200mm × 200mm, and by properly sizing the diffusion sheet, it is advantageous to ensure the rationality of the size and to ensure the miniaturization of the diffusion sheet.
In one embodiment of the present application, to meet the diffusion requirement of the light field design, the width of the curved surface of the microlens is greater than or equal to 10 micrometers and less than or equal to 50 micrometers; the height of the curved surface of the micro lens is more than or equal to 1 micron and less than or equal to 25 microns. The plurality of microlenses are arranged in a periodic array or a random array, and the periodic array can be arranged with certain regularity, such as a matrix grid array; the random array may be one or more of highly random, random in size, random in surface shape, and random in position, the random array in this application is only random in position, and the distance between two adjacent microlenses in at least some microlenses is greater than or equal to 1 micrometer and less than or equal to 50 micrometers.
Specifically, in order to meet the collimation requirement of the light field design, two adjacent ring structures 12 in the plurality of ring structures 12 may be arranged at equal intervals; or at least part of the adjacent two ring structures 12 have different distances; or a plurality of annular structures 12 are arranged at the same height; or at least portions of the ring structures 12 are not equal in height. The distance between two adjacent ring structures 12 in the plurality of tooth-shaped ring structures 12 is greater than or equal to 10 micrometers and less than or equal to 200 micrometers, and the height of each tooth-shaped ring structure 12 may be any value in the range of 1 micrometer to 30 micrometers.
Fig. 1 to 6 are schematic views of a diffusion sheet according to an embodiment of the present disclosure, in which the surface of the microlens is convex. The dimensions of the diffuser sheet may be set to 100 mm long, 40 mm wide and 1 mm high. Fig. 1 shows a schematic view of one side of the diffusion sheet having a ring-shaped structure 12, the plurality of tooth-shaped ring-shaped structures 12 of the fresnel lens layer are concentrically and equally spaced, the spacing is 50 micrometers, and the maximum height of the ring-shaped structures 12 is 18.4 micrometers, so as to achieve the light collimation effect of the fresnel lens layer. As shown in fig. 1, the annular structure 12 at the edge of the fresnel lens layer is not entirely annular but is partial, since the shown surface of the diffuser is rectangular. Fig. 2 shows a schematic cross-sectional view of the diffuser. Fig. 3 is a schematic view showing another angle of the diffusion sheet of the present embodiment, and fig. 4 is a schematic view showing a microlens array region 13 provided on a tooth face 121 of a ring-shaped structure 12, in which surfaces of a plurality of microlenses are each convex.
As shown in fig. 5 and 6, the surface of the microlens is convex, and the surface of the diffusion sheet having the microlens array region 13 may be a light incident surface or a light emergent surface. As shown in fig. 5, a partial optical path diagram of a diffusion sheet as a light exit surface of a tooth surface 121 having a microlens array region 13 is shown, and a plurality of microlenses are stacked in an array along a central axial direction of the tooth surface 121. Wherein the width of the curved surface of the micro lens is 24.5 micrometers, the height of the curved surface is 4.1 micrometers, and the reference center distance is 20 micrometers. The center-to-center spacing of adjacent microlenses may be different at different locations of the microlens array region 13, and may be larger or smaller, such as 20 ± 10% micrometers, with a reference value of 20 micrometers, plus a certain amount of random offset. As can be seen from fig. 5, parallel light rays with different incident angles are incident on the tooth surface 121 of the fresnel lens layer, the tooth surface 121 collimates or approximately collimates the light rays, and then the convex microlenses superposed on the tooth surface 121 implement cross diffusion of the light rays, thereby implementing the functions of collimating and diffusing the light rays. As shown in fig. 6, which is a schematic partial light path diagram of a diffusion sheet when one side surface of the tooth surface 121 having the microlens array region 13 is a light incident surface, parallel light rays with different incident angles are incident on the tooth surface 121 having the microlens array region 13, so that the tooth surface 121 itself and the convex surface realize functions of collimating and cross-diffusing the light rays.
Fig. 7 to 10 are schematic views of a diffusion sheet according to another embodiment of the present disclosure, in which the surfaces of the microlenses are concave. FIG. 7 shows a schematic view of an angle of a diffuser plate. Fig. 8 shows a schematic view of the tooth surface 121 on which the microlens array region 13 is provided, and the surface shapes of the plurality of microlenses in the microlens array region 13 are all concave.
As shown in fig. 9, when the surface of the microlens array region 13 on the side away from the main body 11 is a light exit surface, parallel light rays with different incident angles are incident on the tooth surface 121 of the fresnel lens layer, the tooth surface 121 collimates or approximately collimates the light rays, and then the concave microlenses superposed on the tooth surface 121 diffuse the light rays in the same direction, thereby achieving the functions of collimating and diffusing the light rays. As shown in fig. 10, when the side surface of the microlens array region 13 away from the main body 11 is a light incident surface, parallel light rays of different incident angles are incident on the tooth surface 121 having the microlens array region 13, so that the tooth surface 121 itself and the concave surface perform functions of collimating and codirectionally diffusing the light rays.
As shown in fig. 11, the distribution curve of the transmitted light intensity after the diffusion sheet of the present application is vertically incident at the center is shown. The light emitted from the white light collimation light source with the divergence angle of 3 degrees at the focus of the Fresnel lens layer can output light intensity distribution with the divergence angle of 29 degrees or 13 degrees when the light is vertically incident from the center of the diffusion sheet. As shown in fig. 12, the light spot pattern at the effective window on the illuminated surface is shown above after the light is vertically incident from the center of the diffusion sheet, and the illuminated surface appears as a rectangular light spot; the light spot pattern at the effective window on the illuminated side after light is obliquely incident on the diffuser at a large angle is shown below. After the light enters the diffusion sheet in a large angle such as 15-17 degrees in an inclined mode, although rectangular light spots on an illuminated surface deviate from an effective window, the performance of the diffusion sheet is still obviously better than that of the diffusion sheet without a light path collimation accessory or with a single-side micro lens array, and in conclusion, the diffusion sheet can ensure that the diffusion sheet has higher window efficiency and illumination uniformity under different incidence angles.
It should be noted that, since the difference in optical performance between the convex and concave microlenses is small, fig. 11 and 12 may be described for a diffusion sheet of convex microlenses or a diffusion sheet of concave microlenses.
Specifically, the surfaces of the plurality of microlenses in the microlens array region 13 of the present application may be polynomial surfaces, and the XY polynomial surface equation satisfies:
wherein,
for each location point (x) of the microlens 0 ，y 0 ) Corresponding height value of curved surface, c j Is polynomial coefficient, and m and n are polynomial power exponent.
Wherein j is a coefficient serial number, m is a power exponent of x in each item, and n is a power exponent of y.
The microlenses in the microlens array region 13 are distributed in a periodic or random array on the oxy plane, and the central coordinate points of the microlenses are set to be F in sequence i (a i ，b i ) For any coordinate point P (x, y) on the oxy plane, the center of the coordinate point P is taken as the center of a circle, and the radius is taken as the radius
Assuming that a plurality of points F exist within the circular area of (1) i And can simultaneously satisfy: i x-a i |≤l/2，|y-b i L is more than or equal to w/2, i is more than or equal to 0 and less than or equal to N, wherein l and w are respectively the length and the width of the micro lens, and N is a point F meeting the condition i The number of the cells.
In addition, a plurality of dots F satisfying the above relationship i The curved surface equation of the corresponding micro lens satisfies the following conditions:
when the microlens is convex, the expression of the curved surface of the microlens array region 13 formed by the plurality of microlenses having a convex shape is:
similarly, when the microlens is concave, the expression of the curved surface of the microlens array region 13 formed by the plurality of microlenses having a concave shape takes the minimum value, that is, when the microlens is concaveWhen the micro lens is concave, the surface of the micro lens array area formed by the concave micro lenses satisfies the following conditions:
the tooth surface 121 on which the fresnel lens layer is provided is shown as
When the micro lenses are arrayed along the central axis 15 direction of the Fresnel lens layer, the formed curved surface satisfies the requirement
Wherein, positive corresponds to convex microlens, and negative corresponds to concave microlens.
To sum up, the microlenses in the microlens array region 13 need to satisfy the above inequality condition about the central coordinate and the equation for calculating the height of the curved surface, so as to obtain the initial height of each position of the microlens array region 13 before superposition; the height superposition calculation process when the microlens array region 13 is projected onto the tooth surface 121 of the fresnel lens layer is described by the curved surface relational expression after the microlens array region 13 and the tooth surface 121 are superposed.
The following is explained with reference to specific examples:
in one embodiment, one side of the diffusion sheet having the microlens array area 13 is a light emitting surface, a plurality of microlenses in the microlens array area 13 are overlapped along the central axis 15 direction of the fresnel lens layer, before overlapping, the surface of one side of each microlens far away from the main body portion 11 is convex, and the expression of the convex curved surface of each microlens is that
Wherein the size of the single micro lens satisfies: -12.25 microns x ≦ 12.25 microns, -12.25 microns y ≦ 12.25 microns; wherein, x and y are the positions of the curved surface of the micro lens in the length and width directions respectivelyAnd coordinate values. A plurality of micro lenses are randomly arrayed on the oxy plane according to the uniform distribution function rule, and the central coordinate point of each micro lens is F in sequence i (α i ，b i ) The random value range of the center distance between the adjacent micro lenses is 20 mu m +/-11.25%. With any coordinate point P1(0, 0) on the oxy plane, 4 microlenses exist in a circular area with the radius of 17.3 μm and the coordinate point P1 as the center, the corresponding center points are respectively F1(-6.73, 7.09), F2(11.23, 10.11), F3(8.93, -8.88) and F4(-10.49, 10.86), and the horizontal-vertical spacing component of the point P1 can be satisfied at the same time and is not more than 12.25 μm. At this time, the curved surface equations of the microlenses corresponding to the points Fi satisfying the above relationship are respectively
Accordingly, the height of the microlens array region 13 at the point P1 is
Maximum value of
A positive value. Assuming that the height value of the tooth surface 121 of the Fresnel lens layer satisfies an expression or a point cloud matrix
At this point P1, the tooth surface 121 has a height of
After overlapping the tooth surface 121 and the microlens array region 13, the final height of the spot is
Similarly, other coordinate points on the oxy plane are also calculated in a similar manner.
In another embodiment, as shown in fig. 13, the diffusing sheet has a microlens array region 13 with a light incident surface on one side, the microlenses in the microlens array region 13 are overlapped along the central axis 15 direction of the fresnel lens layer, before overlapping, the surface of each microlens far away from the main body 11 is concave, and the expression of the concave curved surface of the microlens is
Wherein the size of the single micro lens satisfies: -12.25 microns x ≦ 12.25 microns, -12.25 microns y ≦ 12.25 microns; wherein, x and y are the coordinate values of the position of the micro-lens curved surface in the length direction and the width direction respectively. . A plurality of micro lenses are randomly arrayed on the oxy plane according to the uniform distribution function rule, and the central coordinate point of each micro lens is F in sequence i (a i ，b i ) The random value range of the center distance between the adjacent micro lenses is 20 mu m +/-8.3%. With any coordinate point P1(0, 0) on the oxy plane, 4 microlenses exist in a circular area with the radius of 17.3 μm and the coordinate point P1 as the center, the corresponding center points are respectively F1(-6.32, 7.51), F2(10.43, 11.28), F3(7.98, -9.06) and F4(-10.64, 10.67), and the horizontal-vertical spacing component of the point P1 can be satisfied at the same time and is not more than 12.25 μm. At this time, the curved surface equations of the microlenses corresponding to the points Fi satisfying the above relationship are respectively
Accordingly, the height of the microlens array region 13 at the point P1 is
Minimum value of
Is negative. Assuming that the height value of the tooth surface 121 of the Fresnel lens layer satisfies the expression or the point cloud matrix
At this point P1, the tooth surface 121 has a height of
After overlapping the tooth surface 121 and the microlens array region 13, the final height of the spot is
Similarly, other coordinate points on the oxy plane are also calculated in a similar manner.
The application also provides a head-up display device, which comprises the diffusion sheet, a projection optical machine and a reflection element, wherein the projection optical machine is positioned on one side of the diffusion sheet with the annular structure 12 or one side far away from the annular structure 12; the reflecting element is used for receiving the image light emitted by the projector after passing through the diffusion sheet and reflecting the image light to a specified position for displaying. The head-up display equipment with the diffusion sheet has small integral volume and can meet the use requirement of miniaturization; meanwhile, under the condition of ensuring smaller volume, the collimating and diffusing functions of light rays can be realized, the window efficiency and the illumination uniformity of a light field under different incident angles can be improved, and the method has the advantages of low cost and low process difficulty.
It is to be understood that the above-described embodiments are only a few, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
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 is intended to include the plural unless the context clearly dictates otherwise, and it should be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of features, steps, operations, devices, components, and/or combinations thereof.
It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A diffusion sheet, comprising:
the Fresnel lens comprises a light inlet surface and a light outlet surface, wherein one of the light inlet surface and the light outlet surface is provided with a microstructure, the microstructure comprises a tooth surface (121) of a Fresnel lens layer as a base body, a plurality of concave or convex microlenses are arranged on the base body, and the plurality of microlenses are arranged in an array manner to form a microlens array area (13).
2. The diffuser sheet as set forth in claim 1, wherein the surfaces of the microlenses are curved surfaces including one of a spherical surface, a quadratic surface, a polynomial surface, and a free-form surface.
3. The diffusion sheet according to claim 1, wherein the surface of each of the microlenses is arrayed in a direction along a normal (14) to the tooth surface (121) or in a direction along a central axis (15) of the fresnel lens layer.
4. The diffusion sheet according to claim 2, wherein the polynomial surface satisfies:
wherein,
for each position point (x) of the microlens 0 ，y 0 ) Corresponding height value of curved surface, c j Is polynomial coefficient, and m and n are polynomial power exponent.
5. The diffuser sheet as set forth in claim 2, wherein the microlenses are arranged in a periodic or random array on the oxy plane, and the center coordinate point of each microlens is set to F i (a i ，b i ) For a coordinate point P (x, y) on the oxy plane, the radius of the coordinate point P is the center of the circle
Has a plurality of points F within a circular area i And simultaneously satisfies the following conditions: i x-a i |≤l/2，|y-b i L is not less than w/2, i is not less than 0 and not more than N, wherein l and w are respectively the length and width of the microlens, and N is the point F i The number of the cells.
6. The diffuser sheet as set forth in claim 5, wherein a plurality of the points F i The curved surface of the corresponding micro lens meets the following conditions:
7. the diffuser sheet according to claim 4 or 5,
when the microlenses are convex, the surface of a microlens array region (13) formed by a plurality of the microlenses having a convex shape satisfies:
or
When the microlenses are concave, the surface of a microlens array region (13) formed by a plurality of the microlenses having a concave shape satisfies:
8. diffuser according to claim 1, characterized in that the flanks (121) of the fresnel lens layer are provided as indicated
When the surface of each micro lens is arrayed along the central axis (15) direction of the Fresnel lens layer, the surface of the formed microstructure satisfies the condition
9. The diffusion sheet of claim 1, wherein the light incident surface or the light emergent surface is quadrilateral, the length of the quadrilateral is greater than or equal to 20mm and less than or equal to 200mm, and the width of the quadrilateral is greater than or equal to 20mm and less than or equal to 200 mm.
10. A head-up display device, comprising
The diffuser of any one of claims 1 to 9;
the projection light machine is positioned on one side of the diffusion sheet;
and the reflecting element is used for receiving the image light emitted by the projector after passing through the diffusion sheet and reflecting the image light to a specified position for displaying.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210521927.4A CN114879290B (en) | 2022-05-13 | Diffusion sheet and head-up display device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210521927.4A CN114879290B (en) | 2022-05-13 | Diffusion sheet and head-up display device |
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| Publication Number | Publication Date |
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| CN114879290A true CN114879290A (en) | 2022-08-09 |
| CN114879290B CN114879290B (en) | 2024-09-10 |
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| CN111983735A (en) * | 2020-08-25 | 2020-11-24 | 宁波舜宇奥来技术有限公司 | Light diffuser |
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| CN1701278A (en) * | 2003-01-22 | 2005-11-23 | 大日本印刷株式会社 | Fresnel lens sheet and rear projection screen provided with it |
| US20070091444A1 (en) * | 2005-09-16 | 2007-04-26 | Samsung Electro-Mechanics Co., Ltd. | Total internal reflection micro lens array |
| CN111948813A (en) * | 2019-05-17 | 2020-11-17 | 未来（北京）黑科技有限公司 | Head-up display system |
| CN112034673A (en) * | 2019-05-17 | 2020-12-04 | 未来（北京）黑科技有限公司 | Display device, head-up display and motor vehicle |
| CN217543434U (en) * | 2022-05-13 | 2022-10-04 | 宁波舜宇奥来技术有限公司 | Diffusion sheet and head-up display device |
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|---|---|---|---|---|
| CN1701278A (en) * | 2003-01-22 | 2005-11-23 | 大日本印刷株式会社 | Fresnel lens sheet and rear projection screen provided with it |
| US20070091444A1 (en) * | 2005-09-16 | 2007-04-26 | Samsung Electro-Mechanics Co., Ltd. | Total internal reflection micro lens array |
| CN111948813A (en) * | 2019-05-17 | 2020-11-17 | 未来（北京）黑科技有限公司 | Head-up display system |
| CN112034673A (en) * | 2019-05-17 | 2020-12-04 | 未来（北京）黑科技有限公司 | Display device, head-up display and motor vehicle |
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| CN111983735A (en) * | 2020-08-25 | 2020-11-24 | 宁波舜宇奥来技术有限公司 | Light diffuser |
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