CN111303478A - Naked eye 3D display screen material and preparation method thereof - Google Patents

Abstract

A naked eye 3D display screen material and a preparation method thereof are disclosed, the method comprises the following steps: providing a polymer solution of a matrix material dissolved in a volatile solvent, wherein the matrix material is an optically transparent material, and the volatile solvent is not miscible with water; in a constant temperature and humidity closed container, the polymer solution is cast and molded on an optical transparent substrate, and nucleation and growth of water drops on the surface of the polymer solution are promoted through volatilization of a volatile solvent; and standing the optical transparent substrate with the polymer solution in a constant-temperature constant-humidity closed container, and forming a microstructure of a spherical pit left by water drops on the surface of the base material after the volatile solvent and the water drops are completely volatilized, so as to obtain the naked-eye 3D display screen material. The invention can regulate and control the light scattering angle of the display screen material in a larger range, has higher light transmittance and better light intensity distribution uniformity, has simple preparation process, and can be applied to a holographic 3D display system.

Description

Glasses-free 3D display material and preparation method thereof

technical field

The invention belongs to the technical field of naked eye 3D display, and in particular relates to a naked eye 3D display screen material and a preparation method thereof.

Background technique

Nature shows things to human beings in true three-dimensional form, and visual information can vividly reflect the characteristics of things. However, the current mainstream display method is flat two-dimensional display, which loses the depth information of real three-dimensional objects and limits people's correct cognition of objective objects. Therefore, various types of three-dimensional (3D) display technologies emerge as the times require. and fully developed.

3D display is mainly based on the difference of images viewed by people's left and right eyes, and is processed by brain fusion to produce a three-dimensional sense of depth. At present, the 3D display technology is generally wearable display, and people need to wear corresponding auxiliary equipment, such as 3D glasses, 3D helmets, etc., to view 3D images. However, prolonged wearing of the display device will cause severe visual fatigue, and may also cause headaches, nausea and vomiting, etc., thus causing great inconvenience to users and limiting its application range. The naked eye 3D display does not need to wear any auxiliary equipment, so it has gradually attracted the attention and love of businessmen and researchers.

The patent document "A holographic functional screen and its manufacturing method" (application number: 200980100483.X) discloses a holographic functional screen and its manufacturing method, by regulating the size and distribution of speckle particles generated after laser irradiation of diffuse scatterers When the holographic function screen is placed on the specified reference surface, the widening angle of the input light in one direction in space can be exactly the said spatial sampling angle, so as to obtain the recovery of complex wave For the purpose of naked eye 3D display.

During the imaging process of the naked-eye 3D display screen, the incident light emitted by the projector array can form a continuous three-dimensional viewpoint area in space after passing through the screen, so as to meet the requirements of 3D image imaging. The most critical of these is that the screen should have a light scattering angle that matches the projector array and a uniform distribution of light intensity, because too large or too small a light scattering angle will result in blurred images and uneven light intensity distribution. It will cause problems such as "hot spots" and "glare".

However, the naked-eye 3D display screens on the market, such as the aforementioned patents, need to build a corresponding precise optical path for exposure processing by high-power lasers, and also need to prepare and reproduce the template during the processing process. In addition to the high processing cost caused by expensive equipment, complex process, and template damage in the production process, it is more critical that the processing accuracy depends on the size of the speckle, the controllability of the light scattering angle and the distribution of the light intensity. Poor uniformity.

SUMMARY OF THE INVENTION

In view of this, the main purpose of the present invention is to provide a naked-eye 3D display screen material and a preparation method thereof, so as to at least partially solve at least one of the above-mentioned technical problems.

For achieving the above object, technical scheme of the present invention is as follows:

As an aspect of the present invention, a method for preparing a naked-eye 3D display screen material is provided, including the following steps: providing a polymer solution in which a base material is dissolved in a volatile solvent, wherein the base material is an optically transparent material, and the volatile The solvent is not miscible with water; in a constant temperature and humidity closed container, the polymer solution is cast on an optically transparent substrate, and the nucleation and growth of water droplets on the surface of the polymer solution are promoted by volatilizing the volatile solvent; The optically transparent substrate cast with the polymer solution is placed in the constant temperature and humidity closed container, and after the volatile solvent and the water droplets are completely volatilized, a microscopic microscopic view of the spherical pits left by the water droplets is formed on the surface of the base material. structure, that is, the naked-eye 3D display screen material is obtained.

As another aspect of the present invention, a naked-eye 3D display screen material is provided, comprising: an optically transparent substrate; and a base material formed on the optically transparent substrate, wherein the base material is an optically transparent material, and the The surface of the base material forms a microstructure of spherical pits.

Based on the above technical solutions, the naked-eye 3D display screen material and the preparation method thereof of the present invention have the following advantages:

(1) There is no need to customize a template, and the condensation and evaporation process of water droplets are used to obtain pits on the surface of the display material, so as to realize the regulation of the surface morphology of the display material.

(2) By regulating the environmental factors such as temperature and humidity in the preparation process, the size of the pits on the surface of the display screen material is regulated to realize the directional modulation of the incident light.

(3) The preparation method has the advantages of simple process, convenient operation and low cost.

(4) The display screen material can control the light scattering angle in a wide range, and has a high transmittance to ensure the transmission of light information, and the uniformity of light intensity distribution is good, which can be used in holographic 3D display systems .

Description of drawings

1 is a schematic cross-sectional view of the naked-eye 3D display screen material of the present invention;

2 is a test light path diagram of a naked-eye 3D display screen material in Example 1 of the present invention;

3 is an optical topography diagram of a naked-eye 3D display screen material in Example 1 of the present invention;

4 is an optical topography diagram of the display screen material of Comparative Example 1 of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

The naked-eye 3D display screen material and the preparation method thereof provided by the present invention can realize the problem of 3D image imaging after incident light passes through the screen by adjusting the shape of the microstructure on the surface of the screen. The duty cycle can effectively solve the problem of the uniformity of the light intensity distribution, and at the same time, the whole processing technology also has the advantages of simple process and low cost, so it is especially suitable for the application occasion of preparing the holographic function screen.

Specifically, according to some embodiments of the present invention, a method for preparing a naked-eye 3D display screen material is provided, comprising the following steps:

(1) Provide a polymer solution in which a base material is dissolved in a volatile solvent, wherein the base material is an optically transparent material, and the volatile solvent is immiscible with water.

Preferably, the naked-eye 3D display screen material uses an optically transparent homopolymer or copolymer as the base material, such as polystyrene-butadiene-styrene block copolymer (SBS), polycarbonate (PC), polyethylene imine (PEI), polymethyl methacrylate (PMMA), etc. More preferably, it is SBS, which has the advantages of good film-forming performance, uniform microstructure size of the prepared display screen material, and wide adjustable range. As a further preference, the volatile solvent is one or more of carbon disulfide, dichloromethane, chloroform and toluene.

The concentration of the polymer solution is preferably 0.04g/mL to 0.4g/mL, more preferably 0.06g/mL to 0.2g/mL, both too high and too low concentrations will lead to the occupancy of the subsequently formed microstructures The ratio decreases, and the light intensity distribution is uneven.

(2) in a high-humidity constant temperature and humidity airtight container, casting the above-mentioned polymer solution on an optically transparent substrate;

The volatilization of the solvent in the high humidity environment will promote the nucleation and growth of water droplets on the surface of the polymer solution, and the size of the water droplets can be controlled by adjusting the parameters in the preparation process.

It can be understood that a suitable and clean optically transparent substrate should be selected, and the surface of the substrate should be flat. If it is a curved surface, the light will bring additional scattering angles when incident; preferably, the optically transparent substrate should be an optically transparent plate or sheet. , and insoluble in solvent or react with solution, common substrate materials can be silica glass, polyethylene terephthalate, etc.

As a further preference, the relative humidity of the constant temperature and humidity airtight container is preferably 60% to 95%, and the temperature of the airtight container is preferably 15°C to 35°C; the volume-area ratio of the poured polymer solution is preferably 0.02 mL/cm ² ～ 0.5mL/cm ² .

Too high and too low relative humidity, temperature, and volume-to-area ratio will lead to a decrease in the duty cycle of the microstructure and uneven light intensity distribution; large fluctuations in temperature and humidity in a closed container will lead to a decrease in the size of the microstructure. Uncontrollable and uneven.

(3) The optically transparent substrate cast with the polymer solution is placed in a constant temperature and humidity closed container, and after the solvent and the water droplets are completely volatilized, the microstructure of the spherical pits left by the water droplets is formed on the surface of the base material, that is, The naked-eye 3D display screen material.

According to some embodiments of the present invention, a naked-eye 3D display screen material is also provided, which includes an optically transparent substrate and a base material formed on the optically transparent substrate, and the surface of the base material forms a microstructure of spherical pits (see Figure 1), define the radius of the top surface circle of the spherical dimple as d, and the depth of the dimple as h, then d is preferably 0.1 μm to 100 μm, and h is preferably 0.01 μm to 100 μm.

The naked-eye 3D display screen of the present invention can control the light scattering angle within the range of 1° to 45°, and can be applied to a holographic 3D display system.

The invention controls the preparation parameters within a specific range to obtain submicron or even micron-level microstructures with high duty cycle, which can significantly improve the uniformity of light intensity distribution, thereby improving "hot spots", "glare" and other problems. By adjusting the preparation parameters, the d and h of the microstructure can be adjusted, and the precise control of the light scattering angle can be achieved.

The naked-eye 3D display screen material of the present invention adopts an optically transparent substrate and an optically transparent base material, so that the light transmittance of the screen is above 70%, and the higher light transmittance can ensure sufficient transmission of light information.

The present invention is further illustrated below through comparative examples, examples and related test experiments. In the following detailed description, for convenience of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present invention. Obviously, however, one or more embodiments may be practiced without these specific details. Moreover, the details of the following embodiments may be arbitrarily combined into other feasible embodiments without conflict.

Performance Testing:

Transmittance:

A haze meter was used to test the light transmittance of the naked-eye 3D display material.

Light scattering angle and light intensity distribution:

Using the test optical path shown in Figure 2, the light beam emitted by the laser is incident on the naked-eye 3D display screen material, and the optical power meter is moved through the slide rail to measure the outgoing light spot of the naked-eye 3D display screen material, and the light scattering angle and light intensity are obtained. distributed.

Example 1:

First select silica glass as the substrate, then weigh a certain amount of polystyrene-butadiene-styrene block copolymer (SBS) and dissolve it in carbon disulfide to prepare a 0.1g/mL SBS carbon disulfide solution, and then put The aforementioned solution was cast on the surface of the substrate at a volume-area ratio of 0.2 mL/cm ² in a closed container at 25°C and 80% relative humidity, and the volatilization of the solvent promoted the nucleation and growth of water droplets on the surface of the solution. The naked-eye 3D display screen material is obtained. The size range of the radius d of the spherical pit on the screen surface is 25μm±2μm, and the size range of the depth h is 25μm±2μm. After testing, the light scattering angle of the screen is about 40°, the light transmittance is about 75%, and the light intensity evenly distributed. Figure 3 shows the optical topography of the naked-eye 3D display screen, and it can be seen that it has a high duty cycle.

Example 2:

First select silica glass as the substrate, then weigh a certain amount of polycarbonate (PC) and dissolve it in dichloromethane to prepare a 0.14g/mL PC dichloromethane solution, and then heat it at 20°C and 90% relative humidity. The aforementioned solution was cast on the surface of the substrate at a volume-area ratio of 0.3 mL/cm ² in an airtight container, and the volatilization of the solvent promoted the nucleation and growth of water droplets on the solution surface. Material. The size range of the radius d of the spherical pit on the screen surface is 50μm±5μm, the size range of the depth h is 1μm±0.1μm, the light scattering angle of the screen is about 1°, the light transmittance is about 99%, and the light intensity distribution is relatively high. evenly.

Example 3:

Firstly, polyethylene terephthalate was selected as the substrate, and then a certain amount of polyethyleneimine (PEI) was weighed and dissolved in dichloromethane to prepare a 0.06g/mL PEI dichloromethane solution, and then placed in a dichloromethane solution of 0.06 g/mL. The aforementioned solution was cast on the surface of the substrate at a volume-area ratio of 0.1 mL/cm ² in a closed container at 30° C. and 70% relative humidity, and the volatilization of the solvent promoted the nucleation and growth of water droplets on the surface of the solution. The naked-eye 3D display screen material is obtained. The size range of the radius d of the spherical pit on the screen surface is 5μm±0.5μm, the size range of the depth h is 1μm±0.1μm, the light scattering angle of the screen is about 15°, the light transmittance is about 95%, and the light intensity distribution more uniform.

Example 4:

Firstly, polyethylene terephthalate was selected as the substrate, and then a certain amount of SBS was weighed and dissolved in dichloromethane to prepare a 0.06g/mL SBS dichloromethane solution, and then the solution was heated at 30°C and 70% relative humidity. The aforementioned solution was cast on the surface of the substrate at a volume-area ratio of 0.1 mL/cm ² in an airtight container, and the volatilization of the solvent promoted the nucleation and growth of water droplets on the solution surface. Material. The size range of the radius d of the spherical pit on the screen surface is 1μm±0.1μm, and the size range of the depth h is 0.1μm±0.01μm. After testing, the light scattering angle of the screen is about 7°, and the light transmittance is about 91%. , the light intensity distribution is relatively uniform.

Comparative Example 1:

First select silica glass as the substrate, then weigh a certain amount of SBS dissolved in carbon disulfide to prepare a 0.1 g/mL SBS carbon disulfide solution, and then in a closed container at 40 °C and 80% relative humidity at 0.2 mL/cm ² The volume-area ratio of the aforementioned solution was cast on the surface of the substrate, and the solvent and water droplets were completely evaporated. FIG. 4 is an optical topography diagram of the display screen.

Due to the high temperature, the duty cycle of the microstructure on the screen surface is extremely low, and the incident light will directly pass through the screen without scattering, and the concentration of light intensity in the central area will cause a "hot spot" problem.

Comparative Example 2:

First select silica glass as the substrate, then weigh a certain amount of SBS dissolved in carbon disulfide to prepare a 0.14 g/mL SBS carbon disulfide solution, and then in a closed container at 25 ° C and 40% relative humidity at 0.1 mL/cm ² The volume-area ratio of the aforementioned solution was cast on the surface of the substrate, and the solvent and water droplets were completely evaporated.

Because the relative humidity is too low, the transparent SBS screen at this time has no spherical pits on the surface of the screen, and the light does not scatter after passing through the screen.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above-mentioned specific embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention. Within the spirit and principle of the present invention, any modifications, equivalent replacements, improvements, etc. made should be included within the protection scope of the present invention.

Claims (10)

1. A preparation method of a naked eye 3D display screen material comprises the following steps:

providing a polymer solution of a matrix material dissolved in a volatile solvent, wherein the matrix material is an optically transparent material, and the volatile solvent is not miscible with water;

in a constant temperature and humidity closed container, the polymer solution is cast and molded on an optical transparent substrate, and nucleation and growth of water drops on the surface of the polymer solution are promoted through volatilization of a volatile solvent;

and standing the optical transparent substrate cast with the polymer solution in the constant-temperature constant-humidity closed container, and forming a microstructure of a spherical pit left by water drops on the surface of a base material after the volatile solvent and the water drops are completely volatilized, so as to obtain the naked-eye 3D display screen material.

2. The method according to claim 1, wherein the concentration of the matrix material in the polymer solution is 0.04g/mL to 0.4 g/mL.

3. The method of claim 1, wherein the volatile solvent is selected from one or more of carbon disulfide, methylene chloride, chloroform, and toluene.

4. The method according to claim 1, wherein the temperature in the closed container is 15-35 ℃.

5. The preparation method according to claim 1, wherein the relative humidity in the constant-temperature constant-humidity closed container is 60% to 95%.

6. The method of claim 1, wherein the cast polymer solution has a volume-to-area ratio of 0.02mL/cm²～0.5mL/cm²。

7. The method according to claim 1, wherein the matrix material is a homopolymer or a copolymer, preferably selected from a polystyrene-butadiene-styrene block copolymer, polycarbonate, polyethyleneimine or polymethyl methacrylate.

8. The production method according to claim 1, wherein the optically transparent substrate is silica glass or polyethylene terephthalate.

9. A naked eye 3D display screen material comprising:

an optically transparent substrate; and

a base material formed on the optically transparent substrate,

the base material is an optical transparent material, and the surface of the base material forms a microstructure of spherical pits.

10. The naked eye 3D display screen material according to claim 9, wherein the top surface of the spherical pits has a circular radius of 1-100 μm and a pit depth of 0.01-100 μm.

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