CN118038767B - Display system based on Micro-LED display panel - Google Patents
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Classifications
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
- G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
- G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
- G09F9/33—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements being semiconductor devices, e.g. diodes
-
- 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
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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
- G02B3/005—Arrays characterized by the distribution or form of lenses arranged along a single direction only, e.g. lenticular sheets
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- Optics & Photonics (AREA)
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- Devices For Indicating Variable Information By Combining Individual Elements (AREA)
Abstract
The invention belongs to the technical field of projection display, and discloses a display system based on a Micro-LED display panel, which comprises the Micro-LED display panel, a Micro-lens array and an imaging optical system; the Micro-LED display panel is composed of a plurality of LED pixel unit arrays which are arranged in rows and columns; the micro-lens array is composed of a plurality of identical micro-lens units which are arranged in rows and columns; the geometrical centers of the Micro-LED display panel and the Micro-lens array are located on the main optical axis of the imaging optical system, the optical axis of each Micro-lens unit of the Micro-lens array is set to have different inclination angles relative to the main optical axis of the imaging optical system, and the optical axis of each Micro-lens unit in the Micro-lens array passes through the optical center of the imaging optical system. The invention can improve the brightness of the edge part of the light field of the display image by utilizing the inclination of the optical axes of the micro lens units at different positions in the micro lens array, thereby solving the problem of dark angle of the display image in the prior art.
Description
Technical Field
The invention belongs to the technical field of projection display, and particularly relates to a display system based on a Micro-LED display panel.
Background
Micro-display technology based on Micro-LEDs or Micro-OLEDs refers to display technology in which self-luminous Micro-scale LEDs or OLEDs are used as luminous pixel units, and the luminous pixel units are assembled on a driving panel to form a high-density LED array. The micro display chip has the advantages of small size, high integration level, self-luminescence and the like, and has the advantages of display brightness, resolution, contrast, energy consumption, service life, response speed, thermal stability and the like. Based on the above advantages, the micro display chip-based display device can be manufactured as a miniature and portable product, which allows the micro display chip-based display device to be applied to an AV or VR display device.
In the Micro-LED display panel with a microlens array in the prior art as shown in fig. 1, a microlens array layer 200 is disposed on the Micro-LED display panel 100, the microlens array layer 200 is composed of a plurality of microlenses with identical optical parameters arranged in rows and columns, and the microlens head array 200 implements collimation or shaping of light beams emitted by pixels of the Micro-LED display panel 100. However, since the optical axes of the microlens arrays in the prior art are all disposed perpendicular to the Micro-LED display panel, there is generally caused a difference in the intensity of the central portion and the intensity of the edge portion of the optical image light field shaped by the microlens arrays, thereby causing a problem of a dark angle at the edge of the image.
It can be seen that there is a need in the art for a display system based on Micro-LED display panels that can solve the problem of light field image vignetting.
Disclosure of Invention
The technical aim of the invention is to provide a display system based on a Micro-LED display panel, which can solve the defect that a light field image has a dark angle.
Based on the technical purpose, the invention provides a display system based on a Micro-LED display panel, which at least comprises the Micro-LED display panel, a Micro-lens array and an imaging optical system;
The Micro-LED display panel is composed of a plurality of LED pixel unit arrays which are arranged in rows and columns; the micro-lens array is composed of a plurality of identical micro-lens units which are arranged in rows and columns; the imaging optical system is an optical lens formed by a plurality of optical lenses;
Geometric centers of the Micro-LED display panel and the Micro-lens array are positioned on a main optical axis of the imaging optical system, and the Micro-LED display panel and the Micro-lens array are perpendicular to the main optical axis;
the optical axis of each microlens unit of the microlens array is set to have different inclination angles relative to the main optical axis of the imaging optical system, and the optical axis of each microlens unit of the microlens array passes through the optical center of the imaging optical system;
For the microlens unit of the ith row and jth column in the microlens array, the inclination angle θ (i, j) of the optical axis of the microlens unit (i, j) with respect to the main optical axis of the imaging optical system 3 is expressed as:
Wherein m is the number of rows of the micro lens units in the micro lens array, and n is the number of columns of the micro lens units in the micro lens array; p is the spatial dimension of the microlens unit, and L is the distance of the microlens array from the optical center of the imaging optical system.
In one embodiment, the LED pixel unit may be a single color LED element or an LED pixel unit for displaying a color image composed of a combination of a blue LED element, a red LED element, and a green LED element.
In one embodiment, each microlens cell of the microlens array is covered with at least one LED pixel cell under it.
In one embodiment, the imaging optical system is a monolithic structure, a petzval structure, a double gaussian structure, or a pinna structure.
In one embodiment, the microlens array is formed by a PDMS thin film negative pressure process.
In one embodiment, the PDMS thin film negative pressure process includes the preparation of planar microlens arrays.
In one embodiment, the PDMS thin film negative pressure process includes converting a planar microlens array into a microlens array having a curved surface.
In one embodiment, the dimensional relationship of each microlens cell in the microlens array is:
Where r n is the radius of curvature of the microlens unit, h n is the height of the microlens unit, and d n is the diameter of the microlens unit.
In one embodiment, the distance between adjacent microlens units is set to 0.15mm.
One or more embodiments of the present invention may have the following advantages over the prior art:
According to the invention, by utilizing the inclination of the optical axes of the micro lens units at different positions in the micro lens array, the brightness of the edge part of the display image light field can be improved, so that the problem of dark angle of the display image in the prior art is solved.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Drawings
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate the invention and together with the embodiments of the invention, serve to explain the invention, without limitation to the invention. In the drawings:
FIG. 1 is a schematic diagram of a prior art Micro-LED display panel with a microlens array;
FIG. 2 is a schematic diagram of the structure of a Micro-LED display panel with a microlens array of the present invention;
FIGS. 3 a-3 b are schematic diagrams of microlens cell distributions in a microlens array of the present invention;
Fig. 4 is a schematic diagram showing the relationship of sizes of microlens cells in the microlens array of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings, in order to make the objects, technical solutions and advantages of the present invention more apparent.
It will be understood that when an element or layer is referred to as being "on" … …, "" adjacent to "… …," "connected to" or "coupled to" another element or layer, it can be directly on, adjacent to, connected to or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on" … …, "" directly adjacent to "… …," "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention. When a second element, component, region, layer or section is discussed, it does not necessarily mean that the first element, component, region, layer or section is present.
Spatially relative terms, such as "under … …," "under … …," "below," "under … …," "over … …," "above," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements or features described as "under" or "beneath" other elements would then be oriented "on" the other elements or features. Thus, the exemplary terms "below … …" and "under … …" may include both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatially relative descriptors used herein interpreted accordingly.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.
Example 1
As shown in fig. 2, 3a and 3b, the display system based on the Micro-LED display panel of the present embodiment includes a Micro-LED display panel 1, a microlens array 2 and an imaging optical system 3, where the Micro-LED display panel 1 is an LED pixel unit array with row and column pixel arrangement, and the LED pixel unit may be a single-color LED element, such as a blue LED element, a red LED element or a green LED element, or may be an LED pixel unit formed by combining a blue LED element, a red LED element and a green LED element, for displaying a color image.
The microlens array 2 is composed of a plurality of microlenses arranged in rows and columns, as shown in fig. 3a and 3b, the microlens array in this embodiment is composed of m rows and n columns of microlens units with the same size, and the spatial dimension of each microlens unit is p, where the spatial dimension refers to the projection area side length of the microlens unit when the orthographic projection of the microlens unit is square, and the spatial dimension p refers to the diameter of the projection area of the microlens unit when the orthographic projection of the microlens unit is circular.
In this embodiment, a single LED pixel unit is covered under each microlens unit, i.e., the number of microlens units is equal to the number of LED pixel units.
In this embodiment, the imaging optical system 3 is an optical lens formed by a plurality of optical lenses, and according to the imaging requirement, the imaging optical system 3 may be a monolithic structure, a petzval structure, a double gaussian structure, or a soner structure.
In this embodiment, the geometric centers of the Micro-LED display panel 1 and the microlens array 2 are located on the main optical axis of the imaging optical system 3, and the Micro-LED display panel 1 and the microlens array 2 are perpendicular to the main optical axis.
In this embodiment, in order to achieve reduction of the dark angle phenomenon of the light field image formed by the display system, the optical axis of each microlens unit of the microlens array of the present invention is set to have a different inclination angle with respect to the main optical axis of the imaging optical system 3, and the optical axis of each microlens unit of the microlens array passes through the optical center of the imaging optical system 3.
When the microlens array 2 is an m×n microlens cell matrix, and the spatial size of each microlens cell is p, while the optical center distance of the microlens array 2 from the imaging optical system 3 is L.
For the microlens unit of the ith row and jth column in the microlens array 2, the inclination angle θ (i, j) of the optical axis of the microlens unit (i, j) with respect to the main optical axis of the imaging optical system 3 is expressed as:
The optical axis of each microlens unit in the microlens array 2 is adjusted according to the above formula, so that the edge portion in the imaging light field obtains higher brightness, thereby achieving the technical effect of eliminating the dark angle of the image.
The microlens array 2 of this embodiment is formed by adopting a PDMS (polydimethylsiloxane) film negative pressure process, and the specific preparation process includes:
S1, preparing a micro-lens mask film
Computer aided design software or graphic design software is used to make the patterns of the microlens mask. The pattern can reflect the position and shape of each microlens cell on the microlens array. And marking the edge of the mask film and the position of the positioning hole on the pattern.
Then, the microlens reticle pattern is printed on a transparent substrate. The substrate may be a polyester film having excellent heat resistance and mechanical strength. Before printing the pattern, a photosensitive paste needs to be applied to the substrate.
After printing is completed, the substrate is exposed in an exposure machine. The exposure machine irradiates the substrate with ultraviolet rays, so that the photosensitive adhesive is exposed to light at the pattern part and still covered at other parts.
And (3) performing pattern development after the exposure is completed to remove the photoresist layer exposed to light. The substrate is immersed in the solution to dissolve the glue layer in the unexposed portions while the exposed portions remain. From the microlens mask film required for forming the present invention.
S2, preparing a planar micropore array silicon wafer
And using the prepared microlens mask film as a mask plate to reserve patterns on the silicon wafer. Because the silicon wafer needs etching operation, the thinner the thickness of the silicon wafer is, the better the thickness of the silicon wafer is, and the thicker the silicon wafer can influence the etching time and precision, so that the sub-eye size of the prepared fly-eye lens is changed. And the too thin silicon wafer can be mechanically broken in the negative pressure forming process, and is easier to break in the subsequent operation process, so that the silicon wafer with moderate thickness is selected, and the double polished silicon wafer with the thickness of 280 microns is selected in the embodiment.
The wafer needs to be spin coated with an adhesive and photoresist prior to photolithography. The material of the adhesive is Hexamethyldisilazane (HMDS), the adhesive can improve the adhesive capability of the surface of the silicon wafer, so that the photoresist can be more uniformly and smoothly distributed on the surface of the silicon wafer, a double-polished 280-micrometer thick silicon wafer is selected, a proper amount of the adhesive is dripped, the spin coating speed is 1800r/min, and the spin coating time is 45s. Photoresist refers to a thin film material whose solubility changes upon irradiation or radiation by rays of different wavelengths. The photoresist is mainly composed of three materials, namely photosensitive resin, sensitizer and solvent, and the photoresist is used for protecting the surface of the substrate from etching corrosion. The photoresist is classified into two types, one of which is positive photoresist, a portion of the positive photoresist that is not irradiated will be preserved after development, and the other of which is negative photoresist, a portion of the negative photoresist that is irradiated will be preserved after development. The positive photoresist AZ5214 is adopted, the resolution of the photoresist is high, the method is very suitable for preparing a silicon wafer micropore array, the photoresist is influenced by centrifugal force in the spin coating process, a very thin layer with the thickness of about 20 microns is left on the surface of the silicon wafer, and the spin coating parameters of the photoresist are that the rotation speed is 2000r/min and the time is 40s.
After photoresist spinning is completed, the photoresist is solid on the surface of the silicon wafer, but the solvent in the photoresist still accounts for 10 to 30 percent, and the photoresist needs to be subjected to pre-baking operation, so that the solvent content of the photoresist layer is further reduced by the pre-baking operation, the stress generated in the spin coating process of the photoresist layer is reduced, and the adhesive capability of the photoresist on the silicon wafer is improved. The pre-baking temperature is 100 ℃ and the time is 00s. The thickness of the photoresist layer is reduced by the pre-baking process, so that the thickness is about 80% -90% of the original thickness.
Then, ultraviolet exposure is carried out on the silicon wafer covered by the photoresist, the mask plate and the silicon wafer are placed into a photoetching machine, and after ultraviolet exposure, the micro lens array pattern on the mask plate can be copied onto the silicon wafer, and the photoresist at the ultraviolet irradiation position can be subjected to chemical reaction, so that the solubility of the photoresist is greatly improved compared with that of the photoresist at the non-photosensitive position. The aim of photoetching is achieved by utilizing the huge difference of the solubility of the photosensitive area and the non-photosensitive area of the photoresist. The exposure time and the exposure amount can influence the precision of the pattern, insufficient exposure can lead to insufficient photoresist reaction, and the photoresist can not be removed in the developing process. If overexposure occurs, the accuracy of etching is affected. The exposure amount and exposure time need to be adjusted according to the photoresist and the external conditions of the laboratory.
After exposure is completed, developing is carried out, the exposed part of the positive photoresist is dissolved in a developing solution, when a silicon wafer is placed in the developing solution, the exposed structure is carefully observed, the developing time is too short, the photoresist is insufficiently dissolved to influence the subsequent etching step, the developing time is too long, the edge of the pattern structure is damaged, and the line width precision is influenced. After the development process is finished, the surface of the silicon wafer is washed by deionized water, residual developing solution on the surface of the silicon wafer is washed away, the silicon wafer is dried by nitrogen, and the development process is finished.
The post baking process is also called hardening, so that the property of the photoresist is more stable, the solvent in the photoresist is further reduced, and the adhesion capability of the photoresist to the surface of the silicon wafer is improved. The same operation process of pre-baking is carried out, the temperature is 100 ℃, and the time is 200s.
Etching is divided into dry etching and wet etching, the dry etching has the advantages of good anisotropism, high controllability, high precision and the like, ICP plasma etching is to ionize argon gas by a radio frequency power supply in a vacuum environment to form high-density plasma, and the plasma bombards the surface of a sample at a high speed under the action of an electrode RF radio frequency to break chemical bonds of the sample material, react with etching gas to form gaseous substances, and are carried away from the sample. The front surface of the silicon wafer is etched by an ion etching machine for preparing multi-focal-length fly-eye lenses such as ICP and the like by 80 microns, and the part of the silicon wafer which is not protected by photoresist is etched. The etching depth is too large to affect the surface accuracy, so that the through hole cannot be etched at one time, and the photoresist cannot be etched for a long time, so that the front surface of the silicon wafer is etched by 80 microns to ensure the accuracy. After etching, the silicon wafer is cleaned, photoresist on the surface is removed by using ethanol and acetone, then the silicon wafer is put into a boiled sulfuric acid solution to remove impurities on the silicon wafer, and the silicon wafer is alternately washed by cold and hot deionized water so as to avoid impurity residues and influence on subsequent results.
Before back etching, the etched front structure needs to be protected, and here, the front is protected by sputtering a copper film on the front. Magnetron sputtering is a technique in which the surface of a target is bombarded with energetic particles in a vacuum, causing the particles on the target surface to bombard out and deposit on a substrate. In the magnetron sputtering machine, a cathode target is composed of copper, and an anode is a prepared silicon wafer. Argon is filled into the cavity, and the cathode generates glow discharge under the action of direct current negative high pressure, so that argon ions are ionized and bombard a copper target surface, and copper atoms are sputtered and deposited on the silicon wafer. The adoption of the copper film is because the texture of copper is soft and easy to clean, the vacuum degree of the cavity is required to be ensured to be low enough in the process of magnetron sputtering, otherwise, impurities are introduced when the copper target is ionized, so that the sputtered copper film is insufficient in density and has local stress, and the copper film is fallen and damaged. After sputtering, the silicon wafer needs to be kept stand for 24 hours to release stress, so that the protection capability of the copper film is ensured.
Because the depth of back etching reaches 200 micrometers, the photoresist film cannot protect the patterns on the back from being etched, and therefore, a more etching-resistant aluminum film needs to be plated on the back, and the aluminum film melts aluminum wires through high current in a thermal evaporation mode, so that the back of a silicon wafer in a vacuum cavity is plated with a layer of aluminum mask.
After evaporating the aluminum film on the back, back alignment is needed to be carried out on the position with the same structure as the front, wherein the photoetching operation is the same as the front photoetching step, and the attention is paid to the fact that the whole silicon wafer cannot be put into the developing solution in the developing process, the developing solution is dripped on the back of the silicon wafer by a dropper, and the residual developing solution is cleaned up by deionized water in the same mode after the development is finished. And after the development is finished, a small amount of phosphoric acid is dripped on the back of the silicon wafer, the aluminum film with the pattern structure is removed, the back of the silicon wafer is exposed, and at the moment, the preparation of the aluminum mask on the back of the silicon wafer is finished. And etching the back of the silicon wafer by 200 micrometers, removing impurities such as photoresist by using ethanol and acetone, removing an aluminum mask on the back by using phosphoric acid, removing a copper film on the front by using ferric chloride solution, and finally obtaining the final silicon wafer with the micropore array by the operations such as boiling of sulfuric acid.
S3, preparing an initial plane micro-lens array
The invention prepares the plane micro lens array by using the PDMS film negative pressure technology, and PDMS has the advantages of no toxicity, water resistance, inertia and the like in the solid state, and is very suitable for being used as a film structure on a micropore array structure in the invention because of the high elasticity of the structure caused by the low Young modulus, and can be well deformed in the negative pressure deformation process, thereby being used as a micro lens structure of the fly's eye lens. PDMS prepolymer and curing agent are mixed according to the proportion of 10:1, removing bubbles in the mixture, pouring the mixture into a plane, preparing a PDMS film with the thickness of 15 microns under the action of 2000r/min rotation of a centrifugal machine, and covering the film on the prepared microporous structure silicon wafer after the film is solidified, so that the next negative pressure operation can be carried out. Under the same air pressure, the diameter of the through hole and the deformation height of the PDMS film are in a linear relation, and by utilizing the characteristic, the prepared micro lens has different diameters and heights in the same plane, so that different focal lengths of different sub-eyes are realized. NOA63 is colorless transparent ultraviolet curing adhesive, the refractive index is 1.56 under the irradiation of ultraviolet light with the wavelength of 350-380 nm, the curing speed is high, the ultraviolet curing adhesive has low shrinkage and slight elasticity, the transmittance of the curing ultraviolet curing adhesive can reach more than 96% according to the light transmittance given by authorities and the test of a visible spectrophotometer Lambda 850 by experimental equipment, and the curing ultraviolet curing adhesive is shown as the figure, and is the material of the planar array microlens and the multi-focal-length meniscus fly-eye lens. And (3) keeping the air pressure below the silicon wafer unchanged, dripping a proper amount of NOA63 ultraviolet curing adhesive on the silicon wafer covered with the PDMS film, and covering a quartz plate on the upper side to ensure that the prepared planar microlens array has uniform thickness and flat back. The NOA63 ultraviolet curing adhesive is cured completely after being cured for about 3 minutes under an ultraviolet lamp, the curing time can be slightly adjusted according to the power of the ultraviolet lamp and the distance from the ultraviolet lamp to the lens, the insufficient curing time can lead to incomplete curing of the surface of the lens eye, the roughness is greatly improved, and the lens cannot be imaged. The long curing time can cause the color change of the planar microlens, and aging and even cracking occur. After the curing is finished, the NOA63 ultraviolet curing glue and the quartz plate are separated, and the planar microlens array is obtained.
S4, preparation of the planar microlens array of the present invention
After the initial plane micro lens array is obtained, the micro lens plane is required to be converted into a curved surface by adopting a replication and transfer technology, a PDMS transfer mold is required to be prepared, the thickness of the mold can influence the lens prepared in the curved surface transfer process, the stretching amount in negative pressure forming is reduced due to the fact that the PDMS mold is too thick, the breakage can be caused in the stretching process due to the fact that the PDMS mold is too thin, and a mold with the thickness of 3mm is prepared in an experiment. And (3) dropwise adding PDMS on the planar microlens array to enable the PDMS mold to be kept horizontal, putting the PDMS mold into an oven for 80 ℃ curing for 4 hours, taking out the PDMS mold and the planar microlens array, and taking the PDMS mold out of the planar microlens array to obtain the PDMS mold with the concave hole array, wherein the PDMS mold is 3mm thick and has good toughness and can be used for preparing curved fly-eye lenses. The PDMS mold is placed in a self-made mold, negative pressure is applied to the lower portion, the PDMS mold generates uniform deformation under the action of the negative pressure, the air pressure is controlled according to the designed curvature of the substrate, a proper amount of ultraviolet curing optical adhesive NOA63 is dripped, then a spherical quartz lens is covered, the amount of the NOA63 ultraviolet curing adhesive is too small, air bubbles are generated in the curing process, imaging is affected, the dripping amount is too much, the adhesive overflows from the edge, and the post-treatment difficulty is increased. Since the amount of NOA63 ultraviolet curing adhesive dropped in this time is more than the upper amount, irradiation is required under an ultraviolet lamp for 5 minutes, after the irradiation is completed, the PDMS mold, the NOA63 ultraviolet curing adhesive (curved fly-eye lens) and the spherical quartz lens are taken out, and the PDMS mold at the lower layer and the spherical quartz lens at the upper layer are removed, thereby obtaining the final planar microlens array of the invention.
As shown in fig. 4, the dimensional structure geometry of each microlens unit in the microlens array 2 of the present embodiment is:
Where r n is the radius of curvature of the microlens unit, h n is the height (or thickness) of the microlens unit, and d n is the diameter of the microlens unit (side length if the microlens unit is square).
In the present invention, the spacing between the microlens units affects the imaging position of each microlens unit on the optical imaging system 3, the too compact distance can overlap the imaging, and the strength of the silicon wafer covered by the PDMS film can be broken due to the too narrow spacing during negative pressure molding. The distance between the adjacent micro lens units is set to be 0.15mm through comprehensive consideration, so that the rationality of preparation and space utilization is ensured, and crosstalk between images is avoided.
The above description is only a specific embodiment of the present invention, and the scope of the present invention is not limited thereto, and any person skilled in the art should modify or replace the present invention within the technical specification described in the present invention.
Claims (9)
1. The display system based on the Micro-LED display panel is characterized by at least comprising the Micro-LED display panel, a Micro-lens array and an imaging optical system;
The Micro-LED display panel is composed of a plurality of LED pixel unit arrays which are arranged in rows and columns; the micro-lens array is composed of a plurality of identical micro-lens units which are arranged in rows and columns; the imaging optical system is an optical lens formed by a plurality of optical lenses;
Geometric centers of the Micro-LED display panel and the Micro-lens array are positioned on a main optical axis of the imaging optical system, and the Micro-LED display panel and the Micro-lens array are perpendicular to the main optical axis;
the optical axis of each microlens unit of the microlens array is set to have different inclination angles relative to the main optical axis of the imaging optical system, and the optical axis of each microlens unit of the microlens array passes through the optical center of the imaging optical system;
for the microlens unit of the ith row and jth column in the microlens array, the tilt angle θ (i, j) of the optical axis of the microlens unit (i, j) with respect to the main optical axis of the imaging optical system is expressed as:
；
Wherein m is the number of rows of the micro lens units in the micro lens array, and n is the number of columns of the micro lens units in the micro lens array; p is the spatial dimension of the microlens unit, and L is the distance of the microlens array from the optical center of the imaging optical system.
2. The display system according to claim 1, wherein the LED pixel unit can be a single-color LED element or an LED pixel unit for displaying a color image composed of a combination of a blue LED element, a red LED element, and a green LED element.
3. The display system of claim 1, wherein each microlens cell of the microlens array is covered underneath with a unique one of the LED pixel cells.
4. The display system of claim 1, wherein the imaging optical system is a monolithic structure, a petzval structure, a double gaussian structure, or a pinna structure.
5. The display system of claim 1, wherein the microlens array is formed by a PDMS thin film negative pressure process.
6. The display system of claim 5, wherein the PDMS thin film negative pressure process comprises the preparation of a planar microlens array.
7. The display system of claim 5, wherein the PDMS thin film negative pressure process comprises converting a planar microlens array to a microlens array having a curved surface.
8. The display system of claim 1, wherein each microlens cell in the microlens array has a dimensional relationship of:
；
Where r n is the radius of curvature of the microlens unit, h n is the height of the microlens unit, and d n is the diameter of the microlens unit.
9. The display system according to claim 1, wherein a distance between adjacent microlens units is set to 0.15mm.
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| CN109983392A (en) * | 2016-12-09 | 2019-07-05 | 应用材料公司 | Collimate LED light field display |
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| CN114791683B (en) * | 2021-01-25 | 2023-12-05 | 京东方科技集团股份有限公司 | Light-emitting modules, display modules and display devices |
| CN114420803A (en) * | 2022-01-19 | 2022-04-29 | 深圳市思坦科技有限公司 | A preparation method of a Micro-LED display module, a display module and a display device |
| CN114665047B (en) * | 2022-05-20 | 2022-09-23 | 镭昱光电科技(苏州)有限公司 | Display device and preparation method thereof |
| CN116031352A (en) * | 2022-12-20 | 2023-04-28 | 深圳市思坦科技有限公司 | Micro LED structure, manufacturing method thereof and light-emitting device |
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| CN109983392A (en) * | 2016-12-09 | 2019-07-05 | 应用材料公司 | Collimate LED light field display |
| CN113809064A (en) * | 2021-09-22 | 2021-12-17 | 京东方科技集团股份有限公司 | Display panel, display device and light field display device |
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