CN215067620U

CN215067620U - Ultraviolet screen and photocuring 3D printer

Info

Publication number: CN215067620U
Application number: CN202120748010.9U
Authority: CN
Inventors: 刘军; 龚乐; 王臻
Original assignee: Central South University
Current assignee: Central South University
Priority date: 2021-04-13
Filing date: 2021-04-13
Publication date: 2021-12-07
Anticipated expiration: 2031-04-13

Abstract

The utility model discloses an ultraviolet screen and photocuring 3D printer, the ultraviolet screen includes glass substrate, alignment film, TFT, polaroid and liquid crystal; one side of each of the upper glass substrate and the lower glass substrate is covered with an alignment film, and at least one other side of one glass substrate is provided with a TFT (thin film transistor) and a polarizer which are attached in sequence; the upper and lower glass substrates are arranged in parallel with the alignment film side facing each other to clamp the liquid crystal. The high transmittance in the ultraviolet light and visible light range is realized by optimally designing the internal structure of the liquid crystal display screen, so that the ultraviolet light transmittance optical performance of the common liquid crystal display screen is changed, the ultraviolet transmittance can reach more than 30%, the success rate of the photocuring printer in the printing process is favorably improved, the printing work period is further shortened, and the cost is reduced. Compared with the traditional liquid crystal display, the liquid crystal display has no complex structures such as a backlight module, a frame and the like, greatly reduces the cost of the screen, optimizes the process flow of the screen and greatly improves the ultraviolet transmittance of the screen.

Description

Ultraviolet screen and photocuring 3D printer

Technical Field

The utility model belongs to the 3D prints the field, specifically is an ultraviolet screen and photocuring 3D printer.

Background

The photocuring 3D printer has great commercial value due to light equipment, simple operation technology and proper price. However, with the advent of diversified 3D printing products, the requirements for photocuring 3D printing technology are also increasing. The kind of liquid crystal display screen on the market can not meet the new development requirement. At present, the traditional liquid crystal display screen mainly comprises a color liquid crystal display screen and a black and white liquid crystal display screen which are composed of three primary colors (red, green and yellow), and the color liquid crystal display screen and the black and white liquid crystal display screen respectively have the following defects:

the ultraviolet light transmittance of the liquid crystal display screen is very low, incident ultraviolet light can be filtered by the color filter contained in the color screen, so that the ultraviolet light transmittance of the liquid crystal display screen only reaches 0.6%, while the black and white display screen improves the ultraviolet light transmittance by removing the color filter by the color screen, the printing efficiency is improved to a certain extent, but the ultraviolet light transmittance is only 3%, and the utilization rate of the ultraviolet light is very low.

Because the liquid crystal in the traditional liquid crystal display screen needs two layers of polaroids, the light transmission efficiency is less than 50 percent.

The polarization functions of the upper polarizer and the lower polarizer in the conventional liquid crystal display are perpendicular to each other, and the functions of the upper polarizer and the lower polarizer are similar to that of a fence, so that the light wave component is blocked according to requirements, the light wave component perpendicular to the fence of the polarizer is blocked, and only the light wave component parallel to the fence is allowed to pass through.

In addition, the traditional liquid crystal screen uses organic glass, and has certain absorption rate to ultraviolet light.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an ultraviolet screen with high ultraviolet transmittance and have photocuring 3D printer of this ultraviolet screen to improve the success rate of printing the product.

The utility model provides an ultraviolet screen, which comprises a glass substrate, an alignment film, a TFT, a polaroid and a liquid crystal; one side of each of the upper glass substrate and the lower glass substrate is covered with an alignment film, and at least one other side of one glass substrate is provided with a TFT (thin film transistor) and a polarizer which are attached in sequence; the upper and lower glass substrates are arranged in parallel with the alignment film side facing each other to clamp the liquid crystal.

In one embodiment of the above ultraviolet screen, the glass substrate is pure quartz glass or alkali-free borosilicate glass with a thickness of less than 1 mm.

In an embodiment of the ultraviolet panel, the alignment film is made of polymethyl methacrylate.

In one embodiment of the ultraviolet screen, the TFTs and the polarizers are sequentially attached to the outer sides of the two glass substrates.

In one embodiment of the ultraviolet screen, the TFT and the polarizer are sequentially attached to an outer side of one of the glass substrates.

The utility model provides a this kind of photocuring 3D printer, its light source system comprises the ultraviolet lamp pearl of array, and its liquid crystal display is the ultraviolet screen among the above-mentioned technical scheme.

The utility model discloses an ultraviolet screen structure compares in traditional LCD screen, does not have complicated structures such as backlight unit and frame, very big reduction the cost of screen, optimized the process flow of screen, improved the ultraviolet transmittance of screen greatly.

The principle of the high ultraviolet transmittance of the ultraviolet screen is as follows: the utility model provides an ultraviolet screen both can adopt attached polaroid respectively in the outside of two upper and lower glass substrate and also can assemble into the attached polaroid in the glass substrate outside only below the liquid crystal, controls the incident light source towards single direction, and the intensity that the incident light sees through the liquid crystal also changes thereupon. When a light source passes through, the incident light source can be changed by the polarizer to form a linear polarizer in a single direction, and the direction of the linear polarizer is controlled to be consistent with the light moving direction of the polarizer. In the absence of an applied voltage, the optical axes of the PDLC molecules of the small droplets are in a free orientation state, and are not oriented, so that the PDLC molecules cannot form a regular array arrangement, and the effective refractive index of the PDLC molecules is not matched with that of the polymer. Thus, when light enters, it is strongly scattered, so that the light is strongly scattered by the PDLC liquid crystal molecules to be in an opaque milky white state or a translucent state when passing through the glass matrix. When external voltage is applied, the optical axis of PDLC molecules is arranged perpendicular to the surface of the display, i.e. the direction of the PDLC molecules is kept consistent with the direction of an external electric field, so that the refractive index of the PDLC molecules is basically matched with that of the polymer, no obvious interface is generated, and a basically uniform medium is formed, therefore, incident light cannot be scattered, and the display is transparent, so that the ultraviolet transmittance of the display can reach 80%. When the applied electric field is removed, the PDLC liquid crystal molecules restore the original scattering state again, thereby ending the display. In short, the ultraviolet screen of the present invention relies on the optical activity of the liquid crystal, and combines with the control of the external electric field, so as to realize the image informatization display. Based on the high ultraviolet transmittance characteristic of the ultraviolet screen, the ultraviolet screen can also be used in a photocuring 3D printer, the success rate of printing products can be greatly improved, the working period can be shortened, and the printing cost can be greatly reduced.

Drawings

Fig. 1 is a schematic structural diagram of an ultraviolet screen in an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of an ultraviolet screen in the second embodiment of the present invention.

Detailed Description

First embodiment, as shown in fig. 1, the ultraviolet panel disclosed in this embodiment includes a glass substrate 1, an alignment film 2, a TFT (thin film transistor) 3, a polarizer 4, and a liquid crystal 5.

In fig. 1, the opposite sides of two upper and lower glass substrates 1 are covered with alignment films 2, the outer sides of the two glass substrates are attached with TFTs 3 and polarizers 4, respectively, and the space between the two glass substrates is used for filling and clamping the required liquid crystal 5.

The glass substrate of the embodiment adopts high-transmittance pure quartz glass with the thickness of less than 1mm, excellent mechanical properties, heat resistance and chemical corrosion resistance.

The glass substrate of other embodiments can also adopt alkali-free borosilicate glass with the thickness less than 1mm, excellent mechanical property, heat resistance and chemical corrosion resistance according to the requirement, for example, one of ITO glass, FTO glass and AZO glass can be selected according to the actual requirement.

The alignment film 2 is made of Polymethyl Methacrylate (PMMA), and the transmittance thereof is up to 90%.

The Liquid Crystal 5 is a Polymer Dispersed Liquid Crystal (PDLC), and is formed by mixing three compounds of a low molecular Liquid Crystal, a high molecular Polymer and a Polymer according to the mass fraction ratio of 1:2: 1.

The two sides of the liquid crystal 5 are respectively contacted with the alignment films, and the PMMA material of the alignment films can enable PDLC liquid crystal molecules to realize uniform arrangement and orientation on the layer surface of a microscopic size.

The main component of the glass substrate is quartz which can completely transmit ultraviolet rays, and after the glass plate is coated with the alignment film, PMMA can effectively filter ultraviolet rays with the wavelength less than 300 nm and can allow light sources between 300 nm and 450 nm to pass through.

The principle of the high ultraviolet transmittance of the ultraviolet screen is as follows: the utility model provides an ultraviolet screen both can adopt upper and lower two-layer polaroid also can assemble into only a polaroid, controls the incident light source towards single direction, and the incident light sees through the intensity of liquid crystal also changes thereupon. When a light source passes through, the incident light source can be changed by the polarizer to form a linear polarizer in a single direction, and the direction of the linear polarizer is controlled to be consistent with the light moving direction of the polarizer. In the absence of an applied voltage, the optical axes of the PDLC molecules of the small droplets are in a free orientation state, and cannot form regular array arrangement, and the effective refractive index of the PDLC molecules is not matched with that of the polymer. Thus, when light enters, it is strongly scattered, so that the light is strongly scattered by the PDLC liquid crystal molecules to be in an opaque milky white state or a translucent state when passing through the glass matrix. When external voltage is applied, the optical axis of PDLC molecules is arranged perpendicular to the surface of the display, i.e. the direction of the PDLC molecules is kept consistent with the direction of an external electric field, so that the refractive index of the PDLC molecules is basically matched with that of the polymer, no obvious interface is generated, and a basically uniform medium is formed, therefore, incident light cannot be scattered, and the display is transparent, so that the ultraviolet transmittance of the display can reach 80%. When the applied electric field is removed, the PDLC liquid crystal molecules restore the original scattering state again, thereby ending the display. In short, the ultraviolet screen of the utility model can realize information display by relying on the optical activity of the liquid crystal and combining with the control of the external electric field. Based on the high ultraviolet transmittance characteristic of the ultraviolet screen, when the ultraviolet screen is used in a photocuring 3D printer, the success rate of printing products can be greatly improved, the working period can be shortened, and the printing cost can be greatly reduced.

The ultraviolet screen comprises two glass substrates and a liquid crystal box with a certain storage space formed by the space between the two glass substrates, wherein PDLC polymerized composite liquid crystal formed by mixing three compounds of low molecular liquid crystal, high molecular polymer and polymer according to the mass percent of 1:2:1 is injected into the liquid crystal box, the liquid crystal contact sides of the two glass substrates are covered with a layer of organic PMMA, and a layer of polaroid is attached to the contact external light source sides of the two glass substrates.

In the second embodiment, as shown in fig. 2, the difference between the present embodiment and the first embodiment is: no TFT (thin film transistor) is attached to the outside of the glass substrate above the liquid crystal.

Other structures and material selections/configurations of the present embodiment are the same as those of the first embodiment.

In short, the utility model discloses an optimize the inner structure of ultraviolet screen, can realize having high transmittance in ultraviolet ray and the visible light scope, make it have good ultraviolet printing opacity optical property. Tests prove that the ultraviolet transmittance of the ultraviolet screen can reach more than 30%.

Since the ultraviolet screen has high ultraviolet transmittance, the ultraviolet screen can be applied to a photocuring 3D printer.

The corresponding light source system of the 3D photocuring printer can be composed of an ultraviolet lamp bead array, the power is larger than or equal to 300W, and the screen resolution of the ultraviolet screen can be larger than or equal to 2K.

After being applied to photocuring 3D printer with this ultraviolet screen, its ultraviolet printing opacity optical property promotes by a wide margin, is favorable to improving the success rate of photocuring printer at the printing in-process product, also can further shorten the duty cycle of printing, reduce cost.

The utility model discloses in, be higher than 30% with ultraviolet transmittance, screen resolution ratio is not less than 2K's liquid crystal display is ultraviolet screen for short.

Based on the utility model discloses the high ultraviolet luminousness of well ultraviolet screen still can be with its wide application in other photocuring technical field.

Claims

1. An ultraviolet screen, characterized by: the liquid crystal display panel comprises a glass substrate, an alignment film, a TFT, a polarizer and liquid crystal;

one side of each of the upper glass substrate and the lower glass substrate is covered with an alignment film, and at least one other side of one glass substrate is provided with a TFT (thin film transistor) and a polarizer which are attached in sequence;

the upper and lower glass substrates are arranged in parallel with the alignment film side facing each other to clamp the liquid crystal.

2. The uv screen of claim 1, wherein: the glass substrate is pure quartz glass or alkali-free borosilicate glass with the thickness of less than 1 mm.

3. The uv screen of claim 1, wherein: the alignment film is made of polymethyl methacrylate.

4. The uv screen of claim 1, wherein: the outer sides of the upper glass substrate and the lower glass substrate are sequentially attached with the TFT and the polaroid.

5. The uv screen of claim 1, wherein: the TFT and the polaroid are sequentially attached to the outer side of one glass substrate.

6. The utility model provides a photocuring 3D printer which characterized in that: the light source system consists of ultraviolet lamp beads in an array, and the liquid crystal display screen is the ultraviolet screen in claim 1.