Active retroreflective sheeting and method of making same

Abstract

The application relates to an active light-emitting retroreflective film and a preparation method thereof, which comprises a substrate and a retroreflective film layer, the substrate is provided with a reflection structure, the reflection structure comprises a transparent adhesive layer, a plurality of LED chips and a reflection light support body in the shape of a conical boss structure, the LED chips and the reflection light support body are distributed on the substrate at intervals, the transparent adhesive layer encapsulates the LED chips and the reflection light support body on the substrate, a light reflection layer in the shape of an inverted conical pit is arranged on the top of the transparent adhesive layer at a position above the LED chips, the retroreflective film layer comprises a retroreflective base layer and a light-transmitting adhesive layer, the retroreflective base layer is located on the transparent adhesive layer, and the light-transmitting adhesive layer is arranged on the bottom of the retroreflective base layer corresponding to the reflection light support body. The active light-emitting retroreflective film has the advantages of light weight, high light utilization rate, clear display and the like.

Description

Technical Field

[0001] This invention relates to the field of traffic safety equipment, specifically to an active light-emitting retroreflective film and its preparation method. Background Technology

[0002] Existing reflective films are mainly divided into glass bead-type reflective films and microprism-type reflective films. Due to their excellent retroreflective properties, they are widely used in various road traffic safety facilities, signs, and advertising. These types of reflective films require an external light source to illuminate their front surface. The light then passes through the microprisms or glass microbeads and is reflected back into the human eye, allowing the human eye to recognize information such as colors, text, and patterns on the reflective film.

[0003] With the development and application of lighting technologies such as LED light sources, placing the light source on the back of the retroreflective film allows some light to be transmitted from the back, thus illuminating the retroreflective film. This eliminates the need for direct illumination from an external light source and enables the human eye to recognize information such as colors, text, and patterns on the retroreflective film. This provides convenience for people's safe activities and travel at night and for the effective acquisition of information, and is very popular in the market.

[0004] However, existing retroreflective films are designed based on the principle of retroreflection, and the amount of light transmitted from the back is extremely low, typically only around 25%. Because they need to accommodate retroreflection, even after optimization, the transmittance of the back side of the film is unlikely to exceed 50%. Furthermore, because the light emitted from the internal light source is deflected at a large angle after passing through the retroreflective structure, the central light is very weak, resulting in limited light within the effective angle range of -20° to +20° (see attached image). Figure 7 As shown in the figure, this results in extremely low light energy utilization efficiency for such active light-emitting signage structures, leading to a significant waste of energy.

[0005] Furthermore, placing the light source on the back of the retroreflective film usually requires a box to fix and protect the light source, resulting in a heavy retroreflective film structure, complex manufacturing process, and unreliable quality. In addition, the method of setting the light source by making small holes at the corresponding LED light source positions on the retroreflective film and the aluminum alloy base plate on which the retroreflective film is pasted will reduce the strength of the retroreflective film fixing structure, increase the complexity of the manufacturing process, and lead to problems such as difficulty in dust and water protection of the retroreflective film. Summary of the Invention

[0006] The purpose of this invention is to provide an active light-emitting retroreflective film with a thin and light-reducing structure, high light utilization rate, and clear display.

[0007] An active light-emitting retroreflective film includes a substrate and a retroreflective film layer. The substrate has a reflective structure, which includes a transparent adhesive layer, multiple LED chips, and a reflective light support with a conical protrusion structure. The LED chips and the reflective light support are spaced apart on the substrate. The transparent adhesive layer encapsulates the LED chips and the reflective light support on the substrate. The top of the transparent adhesive layer has a reflective layer with an inverted conical recess shape above the LED chips. The retroreflective film layer includes a retroreflective base layer and a light-transmitting adhesive layer. The retroreflective base layer is located on the transparent adhesive layer, and the bottom of the retroreflective base layer has a light-transmitting adhesive layer at a position corresponding to the reflective light support.

[0008] In the above technical solution, the present invention adds a reflective structure to the substrate and the antireflective film layer, forming a three-layered, stacked structure that is tightly bonded to each other. The reflective light support and LED chip inside the reflective structure are arranged at intervals and fixed by the transparent adhesive layer. This eliminates the need for additional fixing structures or other reflective layered structures, significantly saving space. Furthermore, the maximum height of the reflective light support is the maximum height of the reflective structure, with the remaining parts lower than the reflective light support, reducing the overall thickness of the reflective structure. This results in a simpler and more compact structure. Compared to existing products with numerous light-scattering or fixing structures, the present invention is simpler and thinner. The reflective light support is a conical protrusion shape, whose sides can reflect the portion of the vertical light emitted from the LED chip at a large angle, focusing the light angle and projecting it onto the effective area through the transparent adhesive layer. This effectively avoids light waste, reduces power consumption, and improves light utilization. Each LED chip has an inverted cone-shaped reflective layer above it, which reflects a small portion of the vertical light to the side of the reflective light support. After a second reflection from the side of the reflective light support, the light is projected onto the effective area through a light-transmitting adhesive layer, further improving light utilization and greatly reducing light waste and power consumption. The reflective structure is covered with a retroreflective base layer, and a light-transmitting adhesive layer is provided on the top of the reflective light support. The retroreflective base layer can retroreflect light from external light sources. The light-transmitting adhesive layer fills the retroreflective base layer, so that the retroreflective base layer in this area no longer retroreflects light, and light can pass directly through this area, forming a light-transmitting area. The remaining part forms a retroreflective area. Under the combined action of the light-transmitting area and the retroreflective area, the information displayed by the retroreflective film is clearer and more distinct, and the human eye can more easily identify the colors, text, and patterns on the retroreflective film, providing a guarantee for effective information acquisition and safe travel on the road.

[0009] Furthermore, the multiple LED chips disposed on the substrate are arranged in a regular array, and the light-reflecting support is distributed in the intervals between the LED chips.

[0010] In the above technical solution, the multiple LED chips are arranged in a regular pattern of squares, rhombuses or other polygons on the substrate, and the light-reflecting support is distributed in the intervals between the LED chips. The overall distribution is uniform and makes reasonable use of the space on the substrate.

[0011] Furthermore, the transparent adhesive layer fills the gap between the LED chip and the reflective light support, thus encapsulating the LED chip and the reflective light support.

[0012] In the above technical solution, the transparent adhesive layer wraps around the multiple LED chips and the reflective light support, and fills the gap between the LED chips and the reflective light support. The maximum height of the transparent adhesive layer is lower than the height of the reflective light support, so as not to cover the top of the reflective light support and affect the subsequent setting and use of other structures.

[0013] Furthermore, the top of the transparent adhesive layer is provided with an inverted conical recess structure located above the LED chip, and the reflective layer fills the recess structure.

[0014] In the above technical solution, the transparent adhesive layer above the LED chip is provided with an inverted conical reflective layer. The reflective layer contains reflective material, and the generatrix of its inverted conical structure is curved. It can reflect the portion of the light emitted by the LED chip in the vertical direction with a small angle to the adjacent reflective light support. After being reflected a second time by the reflective light support, the light passes through the light-transmitting adhesive layer, so that the light is concentrated and projected onto the effective area, thereby improving the light utilization rate and reducing light waste.

[0015] Furthermore, the retroreflective substrate is provided with a refractive structure with a high refractive index.

[0016] In the above technical solution, the retroreflective substrate is provided with high refractive index glass beads or microprism structures, which can refract the incoming light and reflect it back in the original direction, so that when the retroreflective film is irradiated by an external light source, the information on the retroreflective film can be displayed through retroreflection.

[0017] Furthermore, an adhesive layer is provided on the side of the substrate away from the retroreflective film layer, and the adhesive layer covers and adheres to the bottom surface of the substrate.

[0018] In the above technical solution, an adhesive layer is applied to the other side of the substrate excluding the retroreflective film layer. The adhesive layer covers the entire bottom surface of the substrate and is used to bond with the surface of the object to be used.

[0019] A method for preparing an active light-emitting retroreflective film includes the following steps:

[0020] S1: Select a conductive material as the substrate, and process the power supply circuit on the substrate by vapor deposition, electroplating or printing, and set up multiple pads distributed in an array; set up multiple pads in a regular arrangement of squares, rhombuses or other polygons, and pre-print or apply solder paste at each pad position to facilitate the subsequent soldering of multiple LED chips.

[0021] S2: Based on the power supply circuit, each LED chip is soldered and fixed onto the set pads by reflow soldering to form an LED chip array; the LED chips are fixed at the pre-set pad positions so that each LED chip forms an electrical path with the circuit layer on the substrate, ensuring that the LED chips emit light normally.

[0022] S3: Liquid adhesive with added reflective material is pressurized into a molding machine. At the position between the substrate and the LED chip, the liquid adhesive is vacuum-molded into a conical protrusion shape. The adhesive is then cured at high temperature to form a reflective light support. Subsequently, an anti-reflective base layer is welded to the top surface of the reflective light support using ultrasonic hot melting. A reflective material with reflective properties is then sprayed onto the surface of the reflective light support. The conical protrusion shape, with its curved sides having a certain slope, concentrates and reflects light falling on this curved surface upwards, focusing the light onto the effective area, reducing light waste and greatly improving light utilization. At the same time, an anti-reflective base layer is pre-welded to the top surface of the reflective light support to facilitate the subsequent application of the light-transmitting adhesive layer.

[0023] S4: Using a molding machine, transparent adhesive is vacuum-molded onto the fixed reflective support and LED chip, completely encapsulating the reflective support and LED chip onto the substrate. An inverted conical recess structure is pressed above each LED chip. After high-temperature curing, a transparent adhesive layer is formed. The molding machine encapsulates the reflective support and LED chip with transparent adhesive and encapsulates them onto the substrate, stabilizing the reflective support and LED chip while maintaining and protecting the overall structure.

[0024] S5: A masking film is placed at the inverted conical recess structure on the surface of the transparent adhesive layer. After filling with reflective material, a reflective layer is formed. At the same time, a transparent adhesive with added light-diffusing material is sprayed onto the retroreflective base layer on the top of the reflective support to form a light-transmitting adhesive layer. Before spraying the reflective layer, a masking film is placed at the inverted conical recess structure pre-pressed on the transparent adhesive layer. Then, the reflective material is sprayed to fill the recess structure to form a reflective layer. At the same time, a transparent adhesive with added light-diffusing material is sprayed onto the retroreflective base layer set on the top of the reflective support to form a light-transmitting adhesive layer. The width of the light-transmitting adhesive layer is greater than the width of the top of the reflective support. The light-transmitting adhesive layer can be filled with glass beads or microprism structures in the retroreflective base layer so that light no longer refracts in this area and can pass directly through this area. The transparent adhesive layer that constitutes the light-transmitting adhesive layer contains light-diffusing material, so that the light is more uniform after passing through the light-transmitting adhesive layer and the visual effect is more comfortable.

[0025] S6: After hot pressing and forming by heating the working mold, a planar retroreflective base layer is obtained. The retroreflective base layer is then pasted onto the transparent adhesive layer and the light-transmitting adhesive layer to form a retroreflective film layer.

[0026] Furthermore, during vacuum molding in steps S3 and S4, the pressure applied to press the adhesive is 0-0.5 MPa; during high-temperature curing, the curing temperature is 100-200℃ and the curing time is 1-2 hours.

[0027] In the above technical solution, during vacuum molding, to prevent the molding machine from bearing too much pressure and affecting the molding effect, the pressure range of the glue injection should be controlled within 0-0.5 MPa; during high-temperature curing, the curing temperature is 100-200℃. If the temperature is too low, the curing effect will be poor, and if the temperature is too high, the glue will easily melt again, affecting the molding effect. The curing time is 1-2 hours. If the time is too short, it will not be completely cured, and if the time is too long, the coating will easily age, affecting the product performance.

[0028] Furthermore, in steps S3 and S4, the height range of the light-reflecting support is 0.3-1 mm, and the height range of the transparent adhesive layer is 0.3-1 mm, wherein the maximum height of the transparent adhesive layer is lower than the maximum height of the light-reflecting support.

[0029] In the above technical solution, the maximum height of the transparent adhesive layer must be lower than the maximum height of the light-reflecting support to prevent the adhesive from covering the top of the light-reflecting support and affecting the subsequent installation and use of the light-transmitting adhesive layer or other structures.

[0030] Furthermore, the method also includes a post-process, which refers to coating a polyacrylate or double-sided adhesive on the side of the substrate away from the retroreflective film layer to form an adhesive layer.

[0031] In the above technical solution, the adhesive layer is made of polyacrylate or double-sided tape, which has strong adhesion and good bonding effect, and can be closely attached to the surface of the object to be used.

[0032] Compared with existing technologies, the active light-emitting retroreflective film of this invention has the following advantages:

[0033] First, the structure is thin and light. The present invention adds a reflective structure to the substrate and the anti-reflective film layer, and the whole is a three-layered structure with each other closely attached. Compared with the existing technology products that add more light-scattering structures or fixed structures, it is simpler and thinner.

[0034] Secondly, it has high light utilization. The reflective light support of the present invention is in the shape of a conical protrusion. Its side can reflect the part of the light emitted from the LED chip with a large vertical angle, so that the light angle is focused and projected onto the effective area through the set light-transmitting adhesive layer. This effectively avoids light waste, reduces power consumption, and improves light utilization. At the same time, each LED chip is provided with an inverted conical reflective layer, which can reflect the part of the light with a small vertical angle to the side of the reflective light support. After being reflected a second time by the side of the reflective light support, it is projected onto the effective area through the set light-transmitting adhesive layer, which greatly reduces light waste and power consumption and further improves light utilization.

[0035] Third, the display is clear. The reflective structure is covered with a retroreflective base layer, and a light-transmitting adhesive layer is provided on the top of the reflective light support. The retroreflective base layer can retroreflect light irradiated by an external light source. The light-transmitting adhesive layer is filled in the retroreflective base layer, so that the retroreflective base layer in this area no longer retroreflects light. Light can pass directly through this area to form a light-transmitting area, and the remaining part forms a retroreflective area. Under the combined action of the light-transmitting area and the retroreflective area, the information displayed by the retroreflective film is clearer and more distinct, and the human eye can more easily identify the colors, text, and patterns on the retroreflective film. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the active light-emitting retroreflective film of the present invention.

[0037] Figure 2 for Figure 1 A magnified view of a local area.

[0038] Figure 3 This is a schematic diagram showing the information displayed during the use of the active light-emitting retroreflective film of the present invention.

[0039] Figure 4 This is a schematic diagram of the light source of the active light-emitting retroreflective film of the present invention.

[0040] Figure 5This is a schematic diagram of the light distribution of the LED chip light source described in this invention.

[0041] Figure 6 This is a schematic diagram of the light distribution of the active light-emitting retroreflective film of the present invention.

[0042] Figure 7 This is a schematic diagram of the light distribution of an LED backlight retroreflective film in the prior art. Detailed Implementation

[0043] The active light-emitting retroreflective film of the present invention will be described in further detail below with reference to specific embodiments and accompanying drawings.

[0044] Reference Figures 1 to 6In a non-limiting embodiment of the present invention, an active light-emitting retroreflective film includes a substrate 10 and a retroreflective film layer 30. The substrate 10 has a reflective structure 20, which includes a transparent adhesive layer 24, a plurality of LED chips 21, and a reflective light support 22 with a conical protrusion structure. The LED chips 21 and the reflective light support 22 are spaced apart on the substrate 10. The transparent adhesive layer 24 encapsulates the LED chips 21 and the reflective light support 22 on the substrate 10. A reflective layer 23 with an inverted conical recess shape is provided at the top of the transparent adhesive layer 24 above the LED chips 21. The retroreflective film layer 30 includes a retroreflective base layer 32 and a light-transmitting adhesive layer 31. The retroreflective base layer 32 is located on the substrate 10. On the transparent adhesive layer 24, a light-transmitting adhesive layer 31 is provided at the bottom of the retroreflective base layer 32 at the position corresponding to the reflective light support 22. In this embodiment, the present invention adds a reflective structure 20 to the substrate 10 and the retroreflective film layer 30, forming a three-layered, stacked structure that is tightly bonded to each other. The reflective light support 22 and LED chip 21 inside the reflective structure 20 are arranged at intervals and fixed by the transparent adhesive layer 24. No additional fixing structure or other layered structures to aid reflection are required, greatly saving space. Furthermore, the maximum height of the reflective light support 22 is the maximum height of the reflective structure 20, and the rest is lower than the height of the reflective light support 22, reducing the overall thickness of the reflective structure 20 and making the structure more robust. Simple and compact, this invention is simpler and thinner than existing products with more diffused or fixed structures. The reflective light support 22 is a conical protrusion shape, which reflects the portion of the vertical light emitted from the LED chip 21 at a large angle, focusing the light angle and projecting it onto the effective area through the light-transmitting adhesive layer 31. This effectively avoids light waste, reduces power consumption, and improves light utilization. Simultaneously, each LED chip 21 has an inverted conical reflective layer 23 above it, which reflects the portion of the vertical light at a small angle onto the side of the reflective light support 22. After secondary reflection from the side of the reflective light support 22, the light is projected onto the effective area through the light-transmitting adhesive layer 31, further improving light utilization. This greatly reduces light waste and power consumption. The reflective structure 20 is covered with a retroreflective base layer 32, and the top of the reflective light support 22 is provided with a light-transmitting adhesive layer 31. The retroreflective base layer 32 can retroreflect light irradiated by an external light source. The light-transmitting adhesive layer 31 fills the retroreflective base layer 32, so that the retroreflective base layer 32 in this area no longer retroreflects light. Light can pass directly through this area to form a light-transmitting area 50, and the remaining part forms a retroreflective area 60. Under the combined action of the light-transmitting area 50 and the retroreflective area 60, the information displayed by the retroreflective film is clearer and more distinct. The human eye can more easily identify the colors, texts and patterns on the retroreflective film, which provides a guarantee for the effective acquisition of information and safe travel on the road.In this embodiment, specifically, after the light emitted by the LED chip is reflected and redistributed by the internal structure, the angle of the light rays exiting the retroreflective film is concentrated within the range of -20° to +20°, resulting in a large proportion of light and high light intensity within the effective range.

[0045] Reference Figures 1 to 2 In a non-limiting embodiment of the present invention, the plurality of LED chips 21 disposed on the substrate 10 are arranged in a regular array, and the light-reflecting support 22 is distributed in the intervals between the LED chips 21. In this embodiment, preferably, the plurality of LED chips 21 are arranged in a regular square, rhombus or other polygonal pattern on the substrate 10. In addition to the regular arrangement of square, rhombus or other polygonal patterns, a circular or other centrally symmetrical pattern can also be used. The light-reflecting support 22 is distributed in the intervals between the LED chips 21, and the overall distribution is uniform, making reasonable use of the space on the substrate 10.

[0046] Reference Figures 1 to 2 In a non-limiting embodiment of the present invention, the transparent adhesive layer 24 fills the gap between the LED chip 21 and the reflective light support 22, wrapping the LED chip 21 and the reflective light support 22. In this embodiment, the transparent adhesive layer 24 wraps the plurality of LED chips 21 and the reflective light support 22, and fills the gap between the LED chip 21 and the reflective light support 22. Preferably, the maximum height of the transparent adhesive layer 24 is slightly lower than the height of the reflective light support 22, so as not to cover the top of the reflective light support 22 and affect the subsequent setting and use of other structures.

[0047] Reference Figures 1 to 4 In a non-limiting embodiment of the present invention, the top of the transparent adhesive layer 24 is provided with an inverted conical recess structure above the LED chip 21, and the reflective layer 23 fills the recess structure. In this embodiment, the transparent adhesive layer 24 above the LED chip 21 is provided with an inverted conical reflective layer 23. The reflective layer 23 contains reflective material, and the generatrix of its inverted conical structure is curved. It can reflect the portion of the light emitted by the LED chip 21 in the vertical direction with a small angle to the adjacent reflective light support 22, and then be reflected a second time by the reflective light support 22 before passing through the light-transmitting adhesive layer 31, so that the light is concentrated and projected onto the effective area, improving light utilization and reducing light waste. In this embodiment of the present invention, preferably, the reflective layer 23 is an inverted conical structure with a curved generatrix. This structure is beneficial for reflecting light at an angle downwards to the reflective light support 22. In addition to this structure, a straight line, an arc, or other shaped structure can also be used.

[0048] Reference Figures 1 to 4In a non-limiting embodiment of the present invention, the retroreflective substrate 32 is provided with a high refractive index refractive structure; in this embodiment, preferably, the retroreflective substrate 32 is provided with a high refractive index microprism structure, which can refract incoming light and reflect it back in the original direction, so that when the retroreflective film is irradiated by an external light source, the information on the retroreflective film can be displayed through retroreflection; in this embodiment of the present invention, preferably, the material of the microprism structure is composed of one or more of PMMA, PC, PVC, PU or UV resin.

[0049] Reference Figures 1 to 2 In a non-limiting embodiment of the present invention, an adhesive layer 40 is provided on the other side of the substrate 10 away from the retroreflective film layer 30, and the adhesive layer 40 covers and adheres to the bottom surface of the substrate 10; in this embodiment, the adhesive layer 40 is provided on the other side of the substrate 10 excluding the retroreflective film layer 30, and the adhesive layer 40 covers the entire bottom surface of the substrate 10 for bonding with the surface of the object to be used.

[0050] Reference Figures 1 to 4 In a non-limiting embodiment of the present invention, a method for preparing an active light-emitting retroreflective film includes the following steps:

[0051] S1: Select a conductive material as the substrate of the substrate 10, and process the power supply circuit on the substrate 10 by vapor deposition, electroplating or printing, and set multiple pads distributed in an array; arrange multiple pads in a regular arrangement of squares, rhombuses or other polygons, and pre-print or apply solder paste at each pad position to facilitate the subsequent soldering of multiple LED chips 21; in this embodiment, preferably, the substrate 10 uses PET (polyethylene terephthalate) material as the substrate, but other materials can also be used besides PET material.

[0052] S2: Based on the power supply circuit, each LED chip 21 is soldered and fixed on the set pads by reflow soldering to form an LED chip 21 array; the LED chips 21 are fixed at the pre-set pad positions so that each LED chip 21 forms an electrical path with the circuit layer on the substrate 10, ensuring the normal light emission of the LED chips 21; in this embodiment, preferably, the center-to-center distance between each pair of LED chips 21 is 3-6mm.

[0053] S3: Liquid adhesive with added reflective material is pressed into a molding machine under pressure. At a position on the substrate 10 spaced from the LED chip 21, the liquid adhesive is vacuum-molded into a conical protrusion shape. High-temperature curing is then used to form a reflective light support 22. Subsequently, an anti-reflective base layer 32 is welded to the top surface of the reflective light support 22 using ultrasonic hot-melt technology. A reflective material with reflective properties is then sprayed onto the surface of the reflective light support 22. The liquid adhesive with added reflective material is vacuum-molded to form a reflective light support 22 with a conical protrusion shape, and a reflective material is sprayed onto the surface of the reflective light support 22. The reflective material is sprayed with a conical protrusion structure. Its side is a curved surface with a certain slope, which can concentrate and reflect the light falling on the curved surface upward, so that the light is concentrated and projected into the effective area, reducing light waste and greatly improving light utilization. At the same time, a retroreflective base layer 32 is welded to the top surface of the reflective support 22 in advance, which facilitates the subsequent setting of the light-transmitting adhesive layer 31. In this embodiment, preferably, the reflective support 22 is made of TPU hot melt adhesive, which contains titanium dioxide particles. In addition to the above materials, other hot melt materials, thermosetting materials or thermoplastic materials can also be used.

[0054] S4: Using a molding machine, transparent adhesive is vacuum-molded onto the fixed reflective support 22 and LED chip 21, completely encapsulating the reflective support 22 and LED chip 21 onto the substrate 10. An inverted conical recess structure is pressed out above each LED chip 21. After high-temperature curing, a transparent adhesive layer 24 is formed. The molding machine encapsulates the reflective support 22 and LED chip 21 with transparent adhesive, securing them onto the substrate 10. This stabilizes the reflective support and LED chip 21 while maintaining and protecting the overall structure. In this embodiment, preferably, the transparent adhesive layer 24 is made from a polyacrylate aqueous solution, modified polyurethane aqueous solution, silicone, UV adhesive, or epoxy resin adhesive, with the addition of reflective materials. Besides the above materials, other materials such as hot-melt materials, thermosetting materials, or thermoplastic materials can also be used.

[0055] S5: A masking film is placed at the inverted conical recess structure on the surface of the transparent adhesive layer 24, and a reflective layer 23 is formed after filling it with a reflective material by spraying. Simultaneously, a transparent adhesive containing a light-diffusing material is sprayed onto the retroreflective base layer 32 on top of the reflective support to form a light-transmitting adhesive layer 31. Before spraying the reflective layer 23, a masking film is placed at the inverted conical recess structure pre-pressed into the transparent adhesive layer 24, and then the recess structure is filled with reflective material by spraying to form the reflective layer 23. Simultaneously, a transparent adhesive is sprayed onto the retroreflective base layer 32 set on top of the reflective support 22 to form a light-transmitting adhesive layer 31. Preferably, the width of the light-transmitting adhesive layer 31 is... The width of the light-reflecting support 22 is greater than the top width and less than the bottom width of the light-reflecting support 22. The light-transmitting adhesive layer 31 can be filled with glass beads or microprism structures in the retroreflective base layer 32 so that light no longer refracts in this area and can pass directly through the area. In addition, the transparent adhesive constituting the light-transmitting adhesive layer 31 contains a light-uniforming material, so that the light is more uniform after passing through the light-transmitting adhesive layer 31 and the visual effect is more comfortable. In this embodiment, preferably, the light-transmitting adhesive layer 31 contains at least one of titanium dioxide particles, silicate particles, and plastic particles for light uniformity. In addition to the above materials, other substances with light uniformity properties can also be used.

[0056] S6: After hot pressing and forming by heating the working mold, a planar retroreflective base layer 32 is obtained. The retroreflective base layer 32 is then pasted onto the transparent adhesive layer 24 and the light-transmitting adhesive layer 31 to form a retroreflective film layer 30. In this embodiment, preferably, the thickness of the retroreflective film layer 30 is 0.2-0.5mm.

[0057] In a non-limiting embodiment of the present invention, during vacuum molding in steps S3 and S4, the pressure applied to press the adhesive is 0-0.5 MPa; during high-temperature curing, the curing temperature is 100-200°C, and the curing time is 1-2 hours. In this embodiment, preferably, during vacuum molding, to prevent the molding machine from bearing too high pressure and affecting the molding effect, the pressure applied to press the adhesive is controlled within the range of 0-0.5 MPa; during high-temperature curing, the curing temperature is 100-200°C. If the temperature is too low, the curing effect is poor; if the temperature is too high, the adhesive may melt again, affecting the molding effect. The curing time is 1-2 hours. If the time is too short, it cannot be completely cured; if the time is too long, the coating may age, affecting the product performance.

[0058] Reference Figures 1 to 2In a non-limiting embodiment of the present invention, the height range of the reflective light support 22 in steps S3 and S4 is 0.3-1mm, and the height range of the transparent adhesive layer 24 is 0.3-1mm, wherein the maximum height of the transparent adhesive layer 24 is lower than the maximum height of the reflective light support 22; in this embodiment, preferably, the height range of both the transparent adhesive layer 24 and the reflective light support 22 is 0.3-1mm, wherein the maximum height of the transparent adhesive layer 24 must be lower than the maximum height of the reflective light support 22, so as to prevent the adhesive from covering the top of the reflective light support 22 and affecting the subsequent setting and use effect of the light-transmitting adhesive layer 31 or other structures.

[0059] Reference Figures 1 to 2 In a non-limiting embodiment of the present invention, the method further includes a post-process, which refers to coating the other side of the substrate 10 away from the retroreflective film layer 30 with polyacrylate or double-sided adhesive to form an adhesive layer 40; in this embodiment, preferably, the adhesive layer 40 is made of polyacrylate or double-sided adhesive, which has strong adhesion and good bonding effect, and can be closely attached to the surface of the object to be used.

[0060] In the description of this invention, it should be understood that terms such as "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0061] Furthermore, in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0062] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0063] Although the description of the invention has been given in conjunction with the specific embodiments described above, it will be apparent to those skilled in the art that many substitutions, modifications, and variations can be made based on the foregoing. Therefore, all such substitutions, modifications, and variations are included within the spirit and scope of the appended claims.

Claims

1. An active light-emitting retroreflective film, comprising a substrate and a retroreflective film layer, characterized in that, The substrate is provided with a reflective structure, which includes a transparent adhesive layer, multiple LED chips, and a reflective light support with a conical protrusion structure. The LED chips and the reflective light support are distributed at intervals on the substrate. The transparent adhesive layer encapsulates the LED chips and the reflective light support on the substrate. The top of the transparent adhesive layer has a reflective layer with an inverted conical pit shape above the LED chips. The retroreflective film layer includes a retroreflective base layer and a light-transmitting adhesive layer. The retroreflective base layer is located on the transparent adhesive layer, and the bottom of the retroreflective base layer has a light-transmitting adhesive layer at the position corresponding to the reflective light support.

2. The active light-emitting retroreflective film according to claim 1, characterized in that, The multiple LED chips disposed on the substrate are arranged in a regular array, and the light-reflecting support is distributed in the intervals between the LED chips.

3. The active light-emitting retroreflective film according to claim 2, characterized in that, The transparent adhesive layer fills the gap between the LED chip and the reflective light support, encapsulating both the LED chip and the reflective light support.

4. The active light-emitting retroreflective film according to claim 3, characterized in that, The top of the transparent adhesive layer is provided with an inverted conical recess structure located above the LED chip, and the reflective layer is filled in the recess structure.

5. The active light-emitting retroreflective film according to claim 1, characterized in that, The retroreflective substrate contains a refractive structure with a high refractive index.

6. The active light-emitting retroreflective film according to claim 1, characterized in that, An adhesive layer is provided on the side of the substrate away from the retroreflective film layer, and the adhesive layer covers and adheres to the bottom surface of the substrate.

7. A method for preparing an active light-emitting retroreflective film, characterized in that, The method for preparing the active light-emitting retroreflective film includes the following steps: S1: Select a conductive material as the substrate, and process the power supply circuit on the substrate by means of vapor deposition, electroplating or printing, and set multiple pads distributed in an array. S2: Based on the power supply circuit, each LED chip is soldered and fixed onto the set pads by reflow soldering to form an LED chip array. S3: Liquid adhesive with added reflective material is pressed into a molding machine. At the position between the substrate and the LED chip, the liquid adhesive is pressed into the shape of a conical protrusion through vacuum molding. The adhesive is then cured at high temperature to form a reflective light support. Subsequently, an anti-reflective base layer is welded to the top surface of the reflective light support by ultrasonic hot melting. Reflective material with reflective properties is sprayed on the side of the reflective light support. S4: Using a molding machine, transparent adhesive is vacuum molded onto the fixed reflective light support and LED chip, completely wrapping and encapsulating the reflective light support and LED chip on the substrate, and pressing an inverted conical pit structure above each LED chip. After high-temperature curing, a transparent adhesive layer is formed. S5: Place a masking film at the inverted conical pit structure on the surface of the transparent adhesive layer, fill it with a reflective material to form a reflective layer, and at the same time spray transparent adhesive on the anti-reflective base layer on the top of the reflective support to form a light-transmitting adhesive layer. S6: After hot pressing and forming by heating the working mold, a planar retroreflective base layer is obtained. The retroreflective base layer is then pasted onto the transparent adhesive layer and the light-transmitting adhesive layer to form a retroreflective film layer.

8. The method for preparing the active light-emitting retroreflective film according to claim 7, characterized in that, During vacuum molding in steps S3 and S4, the pressure applied to press the adhesive in is 0-0.5 MPa; during high-temperature curing, the curing temperature is 100-200℃ and the curing time is 1-2 hours.

9. The method for preparing the active light-emitting retroreflective film according to claim 7, characterized in that, In steps S3 and S4, the height range of the light-reflecting support is 0.3-1 mm, and the height range of the transparent adhesive layer is 0.3-1 mm, wherein the maximum height of the transparent adhesive layer is lower than the maximum height of the light-reflecting support.

10. The method for preparing the active light-emitting retroreflective film according to claim 7, characterized in that, The method further includes a post-process, which refers to coating a polyacrylate or double-sided adhesive on the side of the substrate away from the retroreflective film layer to form an adhesive layer.

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