CN114815501A

CN114815501A - Method for processing flat lens

Info

Publication number: CN114815501A
Application number: CN202210431820.0A
Authority: CN
Inventors: 张亮亮; 范超; 韩东成
Original assignee: Anhui Easpeed Technology Co Ltd
Current assignee: Anhui Easpeed Technology Co Ltd
Priority date: 2022-04-22
Filing date: 2022-04-22
Publication date: 2022-07-29

Abstract

The invention discloses a processing method of a flat lens, wherein a spacer is required to be formed on a substrate through stamping when the flat lens is processed. Which comprises the following steps: fixing a substrate on a fixed base, and covering an ink layer on the surface of the substrate; covering the imprinting template on one side of the substrate on which the ink layer is laid, wherein one side of the imprinting template, which faces the substrate, is provided with a convex part, mutually pressing the imprinting template and the substrate, extruding an area, which is opposite to the convex part, on the ink layer into a concave area, and forming an ink block in the concave area of the ink layer; the imprint template is removed from the substrate and the ink mass is cured to form spacers. The processing method greatly improves the forming efficiency of the spacer and can keep the height, the shape, the spacing and other parameters of the spacer. The ink layer is compacted on the substrate by the embossing template, so that the ink block can be firmly adhered to the substrate after being solidified, the formed spacers are not easy to shift on the substrate, and the arrangement of the spacers in the subsequent process can be kept unchanged.

Description

Method for processing flat lens

Technical Field

The invention relates to the field of optical equipment manufacturing, in particular to a method for processing a flat lens.

Background

The planar lens is formed by mutually orthogonalizing two layers of periodically distributed array optical waveguides, so that light rays are respectively subjected to primary total reflection in the two layers of array optical waveguides, and the incident angle during the primary total reflection is identical to the emergent angle during the secondary total reflection due to the mutually orthogonalized rectangular structures. All the rays within the divergence angle of the light source rays will converge correspondingly to the spatial position of the light source symmetrical to the plane of the plate after passing through the plate lens, thus obtaining a 1: 1, floating real image. However, the imaging structure has high requirements on the processing technology, and if the reflecting surface is not parallel or vertical, the generated floating real image is easy to deform.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides a method for processing a flat lens, which is used for improving the processing efficiency of a spacer and improving the processing precision of the spacer so as to improve the imaging effect.

According to the processing method of the flat lens provided by the embodiment of the invention, the flat lens is formed by laminating two optical waveguide lamination layers along the Z direction, each optical waveguide lamination layer is composed of single-column multi-row sub waveguides with rectangular cross sections, and the two optical waveguide lamination layers comprise: the sub-waveguides of the first optical waveguide lamination extend along the X direction and form a plurality of rows along the Y direction, the sub-waveguides of the second optical waveguide lamination extend along the Y direction and form a plurality of rows along the X direction, and the X direction, the Y direction and the Z direction are vertical in pairs; each optical waveguide lamination is formed by superposing transparent parallel flat plates with two sides plated with reflecting films, and each transparent parallel flat plate is a first substrate; when the two optical waveguide laminated layers are laminated into the flat lens, the optical waveguide laminated layer is a second substrate; the first substrate and the second substrate are both substrates; a plurality of spacers are arranged between two adjacent substrates when the two substrates are stacked, and at least one layer of spacers is formed on the substrates through stamping;

the step of forming the spacers by imprinting the substrate includes the steps of:

s1: fixing the substrate on a fixed base, and covering an ink layer on the surface of the substrate;

s2: covering an imprinting template on one side of the substrate on which the ink layer is laid, wherein a convex part is arranged on one side of the imprinting template facing the substrate, the imprinting template and the substrate are pressed mutually, the area, opposite to the convex part, of the ink layer is extruded into a concave area, and an ink block is formed in the concave area of the ink layer;

s3: removing the imprint template from the substrate and curing the ink slug to form the spacer.

According to the processing method of the flat lens provided by the embodiment of the invention, the spacer is processed on the substrate in an imprinting mode, so that the forming efficiency of the spacer is greatly improved, and parameters such as the height, the shape and the spacing of the spacer can be maintained through the size setting of the convex part on the imprinting template. The ink layer is compacted on the substrate by the embossing template, so that the ink block can be firmly adhered to the substrate after being solidified, the formed spacers are not easy to shift on the substrate, and the arrangement of the spacers in the subsequent process can be kept unchanged.

In some embodiments, in step S3, the ink block is cured under the irradiation of ultraviolet light, the wavelength of the ultraviolet light is 200-450nm, and the curing conditions are as follows: the curing environment temperature is 19-25 ℃, the curing environment humidity is lower than 50%, and the range of ventilation and wind power is 0.1-2m/s to eliminate gas volatile matters generated by ink curing.

Specifically, when the ink body is cured under ultraviolet light irradiation in step S3, the wavelength of the ultraviolet light is 365nm or 395nm, or the ultraviolet light is mixed light composed of 365nm and 395nm, and the irradiance 20 of the ultraviolet light is ^- 1500mW/cm ² The total energy requirement of the ultraviolet light reaches 2000-5000mJ/cm ² 。

Specifically, the ink layer is light-cured glue or heat-cured glue.

In some embodiments, the viscosity of the ink before curing is 10000-50000cps, and the shore hardness of the spacer after curing is 70A-90D; the ink layer is one or more of epoxy resin, acrylic resin, chlorinated acrylic resin, vinyl chloride-vinyl acetate copolymer resin, polyurethane and polyamide resin.

Specifically, the ambient temperature in step S2 is maintained at 19-25 ℃.

In some embodiments, when the viscosity of the ink used for the spacers is 10000-30000cps and the shore hardness of the spacers after curing is 25D-40D, the height of the spacers is 10-100 μm and the distance between adjacent spacers is 2-3 mm;

when the viscosity of the adopted printing ink is 10000-30000cps and the Shore hardness of the spacers after curing is 70A-25D, the height of the spacers is 10-100 mu m, and the distance between the adjacent spacers is 0.5-1 mm;

when the viscosity of the ink is 10000-50000cps and the Shore hardness of the spacers after curing is 30D-90D, the height of the spacers is 50-500 mu m and the distance between the adjacent spacers is 10-50 mm, the spacers are arranged between the adjacent second substrates.

In some embodiments, a plurality of fasteners are disposed on the fixing base, and the plurality of fasteners are fastened on the substrate. Therefore, the substrate can be conveniently fixed on the fixed base, the substrate is easy to disassemble and assemble, and the efficiency of processing the spacer on the substrate can be accelerated.

In some embodiments, after at least two of the substrates are stacked by the spacers, a glue pool is connected, wherein glue in the glue pool is filled between adjacent substrates by pressure difference or gravity. Therefore, when glue is filled, the positions of the spacers and the substrates on the two sides are relatively fixed, the spacers are not easy to shift in the glue filling process, and the spacers can still keep proper intervals after glue filling.

In some embodiments, the projections are formed in a mesh shape, and an outer contour of the projections completely covers the ink layer.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a general structural diagram of a flat lens according to an embodiment of the present application.

Fig. 2 is a partially enlarged view of fig. 1 with K in a side view.

Fig. 3 is an exploded view of a flat lens according to an embodiment of the present application.

FIG. 4 is a schematic view of a two-layer orthogonal optical waveguide stack in the Z-direction according to one embodiment of the present application.

FIG. 5 is an imaging schematic of a two-layer orthogonal optical waveguide stack according to an embodiment of the present application.

FIG. 6 is a schematic view of an image of a light source in an X-direction as it passes through a single layer optical waveguide stack according to one embodiment of the present application.

Fig. 7 is a schematic view of the light source image shown in fig. 6 being imaged in a three-dimensional direction through a single-layered optical waveguide stack.

FIG. 8 is a schematic diagram of an imaging optical path of a light source image through two orthogonal optical waveguide stacks according to an embodiment of the present application.

Fig. 9 is a schematic diagram illustrating a processing manner of the optical waveguide stack in an embodiment (the glue layer is omitted in the figure).

Fig. 10 is a schematic view of the processing of the optical waveguide stack in another embodiment (the glue layer is omitted).

FIG. 11 is a schematic view of a spacer manufacturing process according to one embodiment.

Reference numerals:

1. a plate lens;

10. an optical waveguide stack; 11. a first optical waveguide stack; 12. a second optical waveguide stack;

101. a sub-waveguide; 102. a spacer; 103. a glue layer;

30. a protective cover plate; 31. a first cover plate; 32. a second cover plate;

l1, center normal;

p1, video; p2, floating real image;

51. a substrate; 52. a fixed base; 521. a fastener; 53. imprinting a template; 531. a projection; 55. an ink layer; 551. an ink stick.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

A method of processing a flat lens 1 according to an embodiment of the present invention is described below with reference to the drawings.

Before describing the method of processing the flat lens 1, the structure of the flat lens 1 will be briefly described.

The opposite sides of the flat lens 1 are an image source side and a viewing side, that is, the light source of the image P1 is positioned on the image source side, the image P1 can form a floating real image P2 on the viewing side through the flat lens 1, and the floating real image P2 is a real image floating in the air. As shown in fig. 1 to 3, the flat lens 1 is an optical structure in which two periodically distributed optical waveguide stacks 10 are orthogonal to each other, and light is totally reflected once in each of the two optical waveguide stacks 10. Since the two-layered optical waveguide stack 10 has a rectangular structure orthogonal to each other, the incident angle at the time of the first total reflection and the exit angle at the time of the second total reflection become the same. After passing through the flat lens 1, the light rays in the light source light ray divergence angle can be converged to the image viewing side correspondingly, and a light ray which is 1: 1, P2.

In order to enhance the understanding of the technical solution of the present application, the basic structure of the flat lens 1 is described below with reference to fig. 1 to 8, and the imaging principle is explained at the same time.

Referring to fig. 1-3, a flat lens 1 includes two optical waveguide stacks 10. Each optical waveguide stack 10 is formed of a single row of sub-waveguides 101, and each sub-waveguide 101 has a rectangular cross section. Here, the cross section of the sub-waveguide 101 refers to a cross section of the sub-waveguide 101 in a direction perpendicular to the length direction thereof.

Referring to fig. 2-4, two optical waveguide stacks 10 comprise: the optical waveguide structure comprises a first optical waveguide lamination 11 and a second optical waveguide lamination 12, wherein sub-waveguides 101 of the first optical waveguide lamination 11 extend along the X direction and form multiple rows along the Y direction, sub-waveguides 101 of the second optical waveguide lamination 12 extend along the Y direction and form multiple rows along the X direction, the first optical waveguide lamination 11 and the second optical waveguide lamination 12 are arranged along the Z direction, and the X direction, the Y direction and the Z direction are perpendicular to each other. Here, the extending direction of the sub-waveguide 101 is the length direction of the sub-waveguide 101, the length direction of the single sub-waveguide 101 of the first optical waveguide stack 11 is the X direction, the plurality of sub-waveguides 101 of the first optical waveguide stack 11 are closely attached and stacked in the Y direction, and the width direction of the single sub-waveguide 101 is the Y direction; the length direction of the single sub-waveguide 101 of the second optical waveguide stack 12 is the Y direction, the plurality of sub-waveguides 101 of the second optical waveguide stack 12 are closely arranged in a close-fitting manner in the X direction, and the width direction of the single sub-waveguide 101 is the X direction. The two optical waveguide stacks 10 are respectively shaped like a flat plate, and the arrangement direction of the first optical waveguide stack 11 to the second optical waveguide stack 12 is the Z direction, which is also the thickness direction of the flat lens 1. Note that, in the first optical waveguide stack 11 and the second optical waveguide stack 12, the first optical waveguide stack 11 may be adjacent to the image source side, and the second optical waveguide stack 12 may be adjacent to the image source side, which is not limited herein. The two sub-waveguides 101 are perpendicular to each other in the longitudinal direction, and thus the two optical waveguide layers 10 are referred to as being orthogonal to each other.

Alternatively, each of the sub waveguides 101 is provided with a reflective film on each of both side surfaces in the width direction for total reflection of light. For example, the sub-waveguides 101 of the first optical waveguide stack 11 are provided with reflective films on both sides in the Y direction, and the first optical waveguide stack 11 includes a plurality of sub-waveguides 101, so that the plurality of reflective films are arranged in the Y direction in the first optical waveguide stack 11. The sub-waveguides 101 of the second optical waveguide stack 12 are provided with reflective films on both sides in the X direction, and since the second optical waveguide stack 12 includes a plurality of sub-waveguides 101, the second optical waveguide stack 12 is arranged with a plurality of reflective films along the X direction.

In some embodiments, as shown in fig. 1 and 3, the flat lens 1 may further include a protective cover 30, and the protective cover 30 is used for supporting and protecting the optical waveguide stack 10. The protective cover 30 may be provided only on one side of the flat lens 1, or the protective cover 30 may be provided on both sides of the flat lens 1. Specifically, the protective cover 30 is a transparent cover, and optionally, the protective cover 30 is a glass plate.

Fig. 1-3 are schematic structural diagrams of a flat lens 1 according to an embodiment. The flat lens 1 includes a pair of protective covers 30, which are a first cover 31 and a second cover 32, respectively. The slab lens 1 further comprises two optical waveguide stacks 10, respectively a first optical waveguide stack 11 and a second optical waveguide stack 12, located between two protective cover plates 30. The X direction is the extending direction of the sub-waveguides 101 in the first optical waveguide stack 11, the Y direction is the extending direction of the sub-waveguides 101 in the second optical waveguide stack 12, and the Z direction is the thickness direction of the flat lens 1. Of course, it is possible to eliminate the protective cover 30 and protect the optical waveguide stack 10 in other ways.

Alternatively, as shown in fig. 4, the outer contour of the formed optical waveguide stack 10 is rectangular, and the extending direction of each sub-waveguide 101 forms an angle θ with at least two sides of the outer contour of the optical waveguide stack 10. Further optionally, θ satisfies: theta is more than or equal to 30 degrees and less than or equal to 60 degrees, and theta is preferably more than or equal to 45 degrees, and the floating real image P2 is clearer and the afterimage is not obvious under the angle.

Here, the core imaging element of the slab lens 1 is the first optical waveguide stack 11 and the second optical waveguide stack 12, the first optical waveguide stack 11 and the second optical waveguide stack 12 include the single-row multi-row sub-waveguides 101 orthogonal to each other, and the slab lens 1 is a slab as a whole, as shown in fig. 5, which can realize point-to-point aberration-free imaging of the image P1.

The specific imaging principle is as follows: here the two optical waveguide stacks 10 are split. As shown in fig. 6 and 7, the first optical waveguide stack 11 is taken as an example. In the single-layer optical waveguide stack 10, the single-point light on the image source side passes through the single-side optical waveguide stack 10, is divided by the sub-waveguides 101 of each row to be subjected to mirror modulation, and then is converged on a straight line P1' parallel to the X direction again, so that a point-to-line one-dimensional imaging effect is formed. Fig. 6 shows that the incident angle of a single-point light ray on the image source side through a certain sub-waveguide 101 is δ, the exit angle thereof after reflection by the sub-waveguide 101 is δ ', and the incident angle is δ and the exit angle is δ'.

As shown in fig. 8, in order to achieve intersection of two directions (X direction and Y direction) at a single point, it is necessary to use two optical waveguide stacks 10 in combination, so that the arrangement directions of the two sub-waveguides 101 are perpendicular to each other, and point-to-point modulation can be performed on the target light source image P1. Therefore, light rays in any direction can be converged into a floating real image P2 again at the symmetrical position of the optical waveguide lamination 10 by passing through the mutually orthogonal double-layer optical waveguide lamination 10. The imaging distance m2 of the floating real image P2 is the same as the distance m1 to the original image, the floating real image P2 is imaged at equal distance, and the real image can be directly presented in the air without a carrier such as a screen projection and the like because the floating real image P2 is positioned in the air.

Therefore, the plate lens 1 can directly realize the aerial real image of the two-dimensional or three-dimensional light source and realize the real holographic image. The method realizes the naked eye three-dimensional display characteristic while realizing large visual field, large aperture, high resolution, no distortion and no dispersion.

In the drawings of the present application, the flat lens 1 is rectangular, but in other embodiments of the present application, the flat lens 1 may be adjusted in shape as needed, for example, it may be circular, trapezoidal, etc., and is not limited herein.

As shown in fig. 2, two adjacent sub-waveguides 101 in the same optical waveguide stack 10 are separated by a plurality of spacers 102. The gaps between adjacent sub-waveguides 101, except for the spacers 102, are filled with glue layers 103 formed by curing glue.

It will be appreciated that the glue layer 103 is provided to integrate adjacent sub-waveguides 101. The glue layer 103 is formed by glue, air (or nitrogen and the like) in the gap can be extruded out by utilizing the fluidity of the glue, and the phenomenon that the air is remained too much to cause infirm bonding is avoided.

Since the glue layer 103 is formed by curing glue, the mobility of the glue makes the thickness of the glue layer 103 difficult to control in a very fine manner, which may result in a decrease in the parallelism of the adjacent sub-waveguides 101. In the scheme of the application, the adjacent sub-waveguides 101 are spaced by the plurality of spacers 102, the spacers 102 can keep the two adjacent sub-waveguides 101 parallel, and the width of the gap between the adjacent sub-waveguides 101 can be limited to be equal to the height of the spacers 102, so that the sub-waveguides 101 are not easy to push to displace when the glue is cured.

Specifically, each optical waveguide stack 10 can be processed in at least two ways. In one mode, as shown in fig. 9, the optical waveguide stack 10 requires a plurality of transparent parallel plates with reflective films coated on both sides, and after stacking, the adjacent transparent parallel plates are connected by a spacer 102 and a glue layer 103. The individual transparent parallel flat plates are wide and, after being stacked, are integrated into a block structure, which is then divided into a plurality of plate-like optical waveguide stacks 10. In fig. 9, the block structure is cut by three knives to form four optical waveguide stacks 10, and the large transparent parallel plate is cut into four sub-waveguides 101. In fig. 9, a single transparent parallel plate with both sides coated with reflective films before division can be regarded as one substrate 51, and for the convenience of distinguishing from another substrate 51, the transparent parallel plate with both sides coated with reflective films is referred to as a first substrate 511. The plurality of first substrates 511 are filled with glue, cured, and then cut after the spacers 102 are processed and stacked.

Alternatively, as shown in fig. 10, the optical waveguide stack 10 requires a plurality of transparent parallel plates with reflective films coated on both sides, and after stacking, the adjacent transparent parallel plates are connected by spacers 102 and glue layers 103. The width of the single transparent parallel plate is the same as that of the sub-waveguide 101, and the whole stacked transparent parallel plate has a plate-shaped structure, so that an optical waveguide stack 10 can be directly processed without division, and the transparent parallel plate used in fig. 10 is the sub-waveguide 101. In fig. 10, a single transparent parallel plate with reflective films coated on both sides can be regarded as a substrate 51, and such a substrate 51 can also be referred to as a first substrate 511. After the spacers 102 are processed and stacked, the plurality of first substrates 511 are filled with glue and cured.

As shown in fig. 3 and 2, the two finished optical waveguide stacks 10 need to be orthogonal and stacked. The two optical waveguide stacked layers 10 are spaced by a plurality of spacers 102, and the gaps between the two optical waveguide stacked layers 10 except the spacers 102 are filled with glue layers 103 formed by curing glue, so that the two optical waveguide stacked layers 10 can be ensured to be firmly connected and parallel to each other. Since the stacking of two optical waveguide stacks 10 requires the fabrication of spacers 102, a single optical waveguide stack 10 can be regarded as another substrate 51, and such a substrate 51 also requires filling with glue and curing after the fabrication of spacers 102 and stacking. For the sake of distinction, the stack of lightwave layers 10 is referred to as a second substrate 512. In fig. 9 and 10, after the spacers 102 are processed on the first substrates 511 and the filling glue is cured, a plurality of second substrates 512 can be cut or a single second substrate 512 can be directly formed.

In summary, in any substrate 51, the spacer 102 needs to be processed before filling the glue. In the solution of the present application, at least one layer of spacers 102 is formed on the substrate 51 by imprinting. That is, when the optical waveguide stack 10 is processed, the spacers 102 may be formed on one of the transparent parallel plates by imprinting, or the spacers 102 may be formed on the optical waveguide stack 10 by imprinting when two optical waveguide stacks 10 are stacked. By processing the spacers 102 onto the substrate 51 in an embossing manner, the molding efficiency of the spacers 102 is greatly improved, and the spacers 102 do not need to be placed on the substrate 51 one by using a robot.

Specifically, as shown in fig. 11, the substrate 51 is formed with spacers 102 by imprinting, including the steps of:

s1: fixing the substrate on a fixed base, and covering an ink layer 55 on the surface of the substrate;

s2: covering an embossing template on one side of the substrate paved with the ink layer 55, wherein one side of the embossing template facing the substrate is provided with a convex part, mutually pressing the embossing template and the substrate, extruding the area of the ink layer 55 facing the convex part into a concave area, and forming an ink block 551 in the concave area of the ink layer 55;

s3: the imprint template is removed from the substrate and the ink segments 551 are cured to form the spacers.

In step S1, the substrate 51 may be fixed on the fixing base 52, and then the ink layer 55 may be covered on the substrate 51; the substrate 51 may be fixed to the fixed base 52 after the ink layer 55 is first coated on the substrate 51. Alternatively, the ink layer 55 is formed on the substrate 51 by spraying, or may be formed on the substrate 51 by other means, such as brushing.

Alternatively, the fixing of the substrate 51 to the fixing base 52 may be performed manually, and the rest of the imprinting operation may be performed automatically by a machine, to improve the degree of automation.

The shape and size of the projections 531 on the imprint template 53 enable the ink block 551 to be pressed toward the region without the projections 531, and the shape of the ink block 551 thus formed is in a substantially complementary relationship with the shape of the projections 531, so that the shape of the projections 531 substantially determines the shape, size, etc. of the spacers 102.

When the embossing template 53 is replaced with the different protrusions 531, spacers 102 of different shapes and sizes can be formed. The pitch of the projections 531 also determines the pitch of the spacers 102. Compared with other processing modes, the arrangement of the convex part 531 on the stamping template 53 solves the problems of the shape, the arrangement parameters and the like of the spacers 102 at one time, not only is the processing efficiency high, but also the arrangement precision of the spacers 102 is high, and the problem of uneven spacing of the spacers 102 caused by factors such as mechanical jitter and matching errors is reduced.

According to the method for processing the flat lens 1 of the embodiment of the present invention, the spacer 102 is processed on the substrate 51 by imprinting, so that the efficiency of forming the spacer 102 is greatly improved, and the parameters such as the height, shape, and pitch of the spacer 102 can be maintained by setting the size of the protruding portion 531 on the imprint template 53. Since the ink layer 55 is pressed against the substrate 51 by the imprint template, the ink segments 551 can be firmly adhered to the substrate 51 after curing, so that the spacers 102 formed in this way are not easily displaced on the substrate 51, and the arrangement of the spacers 102 in the subsequent process can be maintained.

The manner of curing of the ink segments 551 is not particularly limited and may be selected by one skilled in the art according to the actual needs, according to some embodiments of the present invention.

In the scheme of the application, the ink block 551 can be cured naturally, can be cured by heating, and can also be cured under the irradiation of ultraviolet light. If UV light curing is used, UV inks are correspondingly selected. The UV ink is ink which does not use solvent, has high drying speed, good gloss, bright color, water resistance, solvent resistance and good wear resistance, and can generate cross-linking polymerization reaction under the irradiation of UV light (the wavelength range is within 200-450 nm) to instantly solidify and form a film. And the UV printing ink becomes a mature printing ink technology, and the pollution emission is almost zero.

According to some embodiments of the present invention, in step S3, the ink segments 551 form the spacers 102 through natural curing, wherein the parameters of the natural curing are: the natural curing time is 10s-5min, the humidity is lower than 50%, the direct sun exposure is avoided, and the ventilation is realized at the wind speed of 0.1-2 m/s. Therefore, when natural curing is adopted, direct sunlight is avoided, uneven temperature caused by sunlight irradiation is avoided, and uneven curing caused by overlarge temperature fluctuation can be avoided. In addition, the direct sunlight and humidity limitation can be avoided, and the condensation phenomenon caused by insufficient temperature and overhigh humidity can be avoided.

According to some embodiments of the present invention, the ink segments 551 are cured by heating in step S3, and the heating temperature for heating curing is selected from 19-150 ℃ compared to natural curing. This can shorten the curing time.

According to other embodiments of the present invention, in step S3, the ink block 551 is cured under the irradiation of ultraviolet light, the wavelength of the ultraviolet light is 200 nm and 450nm, and the curing conditions are as follows: the curing environment temperature is 19-25 ℃, the curing environment humidity is lower than 50%, and the range of ventilation and wind power is 0.1-2 m/s. Therefore, the influence of environmental factors on the curing process of the spacers 102 can be avoided, and the spacers 102 are guaranteed to have qualified height uniformity.

Specifically, when the ink patch 551 is cured under the irradiation of ultraviolet light in step S3, the wavelength of the ultraviolet light is 365nm or 395nm, or the ultraviolet light is a mixed light composed of 365nm and 395nm, and the irradiance of the ultraviolet light is 20-1500mW/cm ² The total energy requirement of the ultraviolet light reaches 2000-5000mJ/cm 2. This allows the ink to harden rapidly under uv light, forming a robust spacer 102.

In some embodiments, the stamp template 53 and the substrate 51 are pressed against each other at step S2 under a pressure of 0.3 to 11bar, an ambient temperature of 19 to 25 ℃, and an ambient humidity of less than 50%, thereby preventing excessive temperature fluctuation or excessive humidity from affecting curing stability.

In particular, the pressure is adjustable during the embossing process.

In some embodiments, the ambient temperature in step S2 is maintained at 19-25 ℃, which can avoid the ambient temperature fluctuation from affecting the molding stability of the spacer 102 too much.

The specific type of material of the ink according to some embodiments of the present invention is not particularly limited, and may be selected by those skilled in the art according to actual needs. According to some embodiments of the present invention, the ink layer 55 is a photo-curable adhesive or a thermal-curable adhesive.

Specifically, the ink layer is one or more of epoxy resin, acrylic resin, chlorinated acrylic resin, vinyl chloride-vinyl acetate copolymer resin, polyurethane and polyamide resin. Thereby, the hardness, adhesive strength, water resistance, and the like of the spacer 102 are ensured.

It should be noted that, in order to ensure the processing quality and the imaging effect of the flat lens 1, the inventor team has conducted intensive research on each production link of the flat lens 1. The imaging quality of the plate lens 1 is related to the quality of the transparent parallel plate itself, the parallelism of the transparent parallel plate when the transparent parallel plate is laminated into the optical waveguide laminate 10, and the parallelism of the two optical waveguide laminates 10.

Here, after the transparent parallel plates (first substrates 511) are stacked, they are adhered by glue to form the optical waveguide stack 10, and the two optical waveguide stacks 10 (second substrates 512) are adhered by glue to form the plate lens 1. The key influencing factor of the parallelism of the two adjacent first substrates 511 and the parallelism of the two second substrates 512 is the uniformity of the thickness of the glue layer 103 formed after the glue is cured. However, the adhesive layer 103 generates stress when curing and shrinking, and it is difficult to keep the shrinking stress of the adhesive layer 103 uniform.

In order to solve the technical problem, the spacer 102 is used to ensure the uniformity of the thickness of the adhesive layer 103 in the scheme of the application. The spacers 102 are machined directly on the substrate 51 during machining, and the shape, height and pitch of the spacers 102 are ensured by the provision of the projections on the imprint template.

In order to ensure the supporting effect of the spacer 102, the viscosity of the ink before curing is defined to be 10000-50000cps, and the shore hardness of the spacer 102 after curing is 70A-90D.

It will be appreciated that if the viscosity of the ink used to make the spacer 102 is not suitable, there are a number of adverse consequences.

If the ink viscosity is too low, the ink flow is high, the molding is difficult, and the height/area value is too high, the density of the spacers that can be formed decreases, and the support of the spacers 102 decreases. When subsequently bonding the substrate 51 and the substrate 51, it is necessary to fill the space between the substrate 51 and the substrate 51 with glue. If the support of the spacers 102 is insufficient, the substrate 51 is easily deformed by stress generated by curing shrinkage of the glue, and finally the image distortion of the flat lens 1 is caused.

Moreover, if the height/area value is too large, the area occupied by the ink of the whole substrate is too large, the adhesive area of the glue after subsequent glue filling is reduced, and the phenomena of poor adhesion and substrate 51 fracture can be generated.

On the contrary, if the viscosity of the ink is too high, the amount of ink ejected each time is difficult to control accurately, so that the spacers 102 are not uniform enough, the supporting function of the spacers 102 is also deteriorated, and finally the substrate 51 is easily deformed, and the image of the manufactured flat lens 1 is distorted.

For the above reasons, the inventors set the viscosity of the ink to 10000-. The spacers 102 can be arranged in a proper density, the shore hardness of the spacers 102 after curing can reach 70A-90D, and sufficient support of the spacers 102 is guaranteed. The spacers 102 are not easy to collapse and deform after being stressed, so that the adhesive area of the glue is sufficient and the adhesion is firm, and the substrate 51 is not easy to break.

In addition, the shore hardness of the spacer 102 is set to 70A-90D, the hardness is lower than 70A, the spacer 102 is not easy to deform enough to play a supporting role, the hardness is higher than 90D, and the surface layer of the substrate 51 is deformed or damaged due to the fact that the hardness of the spacer 102 is too high.

Next, a plurality of examples of forming spacers 102 on the first substrate 511 and the second substrate 512 by imprinting and filling and curing the adhesive with glue are used to compare the setting requirements of the spacers 102 in each example and the possible influence of the requirements, as shown in table 1 below.

TABLE 1

In the above embodiments, the filling glue parameters and their effects are shown in table 2 below.

TABLE 2

In some embodiments, the height error of the spacers 102 is ≦ 10%. The height error of the spacers 102 is limited to be not more than 10%, so that the difference between the distances of the substrates 51 at different positions does not exceed 10%, and the situation that the spacers 102 are too short to form effective support between the two substrates 51 is avoided, so that the spacers 102 can be prevented from being displaced during glue pouring.

In some embodiments, as shown in fig. 11, a plurality of fasteners 521 are disposed on the fixing base 52, and the plurality of fasteners 521 are fastened on the base 51. This makes it possible to fix the substrate 51 to the fixed base 52 very easily, to easily attach and detach the substrate 51, and to increase the efficiency of processing the spacers 102 on the substrate 51. Of course, the present disclosure is not limited thereto, and in other embodiments, the substrate 51 may be clamped on at least two horizontal sides of the substrate 51 by using the clamping blocks when the substrate 51 is fixed on the fixing base 52.

Optionally, the substrate 51 is sucked onto the stationary base 52 by a negative pressure to ensure that the substrate 51 is completely immobilized with respect to the stationary base 52 during the imprinting process.

In some embodiments, the ink segments 551 are cured when the imprint template 53 is not pulled apart, and in some embodiments, the ink segments 551 are cured after being pulled apart from the imprint template 53, which is not limited herein.

In some alternative embodiments, the protrusion 531 is formed in a net shape, and the outer contour of the protrusion 531 completely covers the ink layer 55. Thus, when the ink layer 55 is pressed by the projections 531, the ink layer 55 is pressed in a grid pattern, and each individual grid pattern forms an ink block 551, which is finally cured to form the spaced spacers 102. Thus, when the subsequent substrate 51 is filled with glue, the spacers 102 are not connected into a line, which is beneficial to filling the gaps with glue.

In some alternative embodiments, the imprint template 53 is cleaned after multiple uses to prevent residual ink from curing to occupy the corner areas of the projections 531.

In some cases, the imprint template 53 is detachably provided on the fixed base 52. Here, the imprint template 53 may be removed and cleaned, or the entire processing apparatus may be cleaned as it is.

In the present embodiment, the material of the imprint template 53 is optional, and a material having a high hardness and a high degree of adhesion to the substrate 51, such as a resin, may be selected according to the type of the substrate.

In some embodiments, after at least two substrates 51 are stacked by the spacers 102, a glue pool is connected, in which glue is filled between adjacent substrates 51 by pressure difference or gravity. Thus, during glue filling, the positions of the spacers 102 and the substrates 51 on the two sides are relatively fixed, the spacers 102 are not easy to shift in the glue filling process, and the spacers 102 can still keep a proper distance after glue filling.

Specifically, after the spacers 102 are formed on the substrate 51 by stamping, the lamination is performed by a robot arm, and then the laminated structure is sandwiched and placed in a glue bath. After the glue is placed in a glue pool, vacuum pumping can be carried out to form negative pressure, so that glue is injected into the laminated gap, and gluing is realized after the glue generates a thermosetting reaction when the temperature reaches a certain temperature. In some schemes, the relative position of the glue pool and the laminated structure is changed, and at the moment, the glue can automatically flow into the laminated gap by using gravity. In another embodiment, the glue is filled by driving the glue with a pressure difference, but the glue reservoir may be pressurized to force the glue into the lamination gap.

Since the spacers 102 have the same hardness and adhesion, and are not displaced after gravity lamination during lamination, the spacers 102 are not displaced during the gluing process. The ink, after curing, adheres to the surface of the substrate 51 with sufficient adhesion to ensure that the spacer 102 does not move during lamination.

In the description herein, references to the description of the terms "embodiment," "example," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least some embodiments or examples of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are exemplary and not to be construed as limiting the present invention, and that changes, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A method for processing a flat lens, wherein the flat lens is formed by stacking two optical waveguide stacks along a Z direction, each optical waveguide stack is formed by sub-waveguides which are single-row multi-row and have rectangular cross sections, and the two optical waveguide stacks comprise: the sub-waveguides of the first optical waveguide lamination extend along the X direction and form a plurality of rows along the Y direction, the sub-waveguides of the second optical waveguide lamination extend along the Y direction and form a plurality of rows along the X direction, and the X direction, the Y direction and the Z direction are vertical in pairs;

each optical waveguide lamination is formed by superposing transparent parallel flat plates with two sides plated with reflecting films, and the transparent parallel flat plates are first substrates; when the two optical waveguide laminated layers are laminated into the flat lens, the optical waveguide laminated layer is a second substrate; the first substrate and the second substrate are both substrates;

a plurality of spacers are arranged between two adjacent substrates when the two substrates are stacked, and at least one layer of the spacers is formed on the substrates through stamping;

s3: and removing the imprint template from the substrate, and curing the ink block to form the spacers.

2. The method as claimed in claim 1, wherein the ink block is cured under the irradiation of ultraviolet light at a wavelength of 200-450nm in step S3 under the following conditions: the curing environment temperature is 19-25 ℃, the curing environment humidity is lower than 50%, and the range of ventilation and wind power is 0.1-2m/s, so that gas volatile matters generated by curing the ink are eliminated.

3. The method according to claim 2, wherein when the ink body is cured in step S3 under irradiation of ultraviolet light having a wavelength of 365nm or 395nm, or a mixed light of 365nm and 395nm, the irradiance of the ultraviolet light is 20mW/cm ² -1500mW/cm ² The total energy requirement of the ultraviolet light reaches 2000-5000mJ/cm ² 。

4. The method of claim 1, wherein the ink layer is a photo-curable glue or a thermal-curable glue.

5. The method as claimed in claim 1, wherein the viscosity of the ink before curing is 10000-50000cps and the shore hardness of the spacer after curing is 70A-90D; the ink layer is one or more of epoxy resin, acrylic resin, chlorinated acrylic resin, vinyl chloride-vinyl acetate copolymer resin, polyurethane and polyamide resin.

6. The method according to claim 1, wherein the ambient temperature in step S2 is maintained at 19-25 ℃.

7. The method of claim 1,

when the viscosity of the ink is 10000-30000cps and the Shore hardness of the spacers is 25D-40D after curing, the height of the spacers is 10-100 mu m and the distance between the adjacent spacers is 2-3 mm;

when the viscosity of the ink is 10000-30000cps and the Shore hardness of the spacers after curing is 70A-25D, the height of the spacers is 10-100 mu m and the distance between the adjacent spacers is 0.5-1 mm;

8. The method of claim 1, wherein the fixture base has a plurality of snaps positioned thereon, the plurality of snaps being snapped onto the substrate.

9. The method according to claim 1, wherein after at least two of said substrates are stacked by said spacers, a glue reservoir is connected, in which glue is filled between adjacent said substrates by pressure difference or gravity.

10. The method according to any one of claims 1 to 9, wherein the projections are formed in a net shape, the outer contour of the projections completely covering the ink layer.