Microprism reflective film combined by three triangular pyramids and manufacturing method of mold of microprism reflective film

Abstract

The invention relates to a microprism reflective film combined by three kinds of triangular pyramids and a manufacturing method of a mold of the microprism reflective film, the surface of the microprism reflective film is formed by an array of identical parallelogram unit bodies (1), each parallelogram unit body (1) is composed of four identical triangular pyramids A, one triangular pyramid B and three identical triangular pyramids C, the directions of the four triangular pyramids A and the directions of the three triangular pyramids C and the triangular pyramids B form 180 degrees, and the three triangular pyramids C and the triangular pyramids B are arranged among the four triangular pyramids A in a staggered manner; the bottom surfaces of the triangular pyramids B and C are the same equilateral triangles, the inclination angles of the three pyramid surfaces of each triangular pyramid A are alpha / 2, the inclination angles of the pyramid surfaces of the triangular pyramids B are beta / 2, and the inclination angles of the three pyramid surfaces of the triangular pyramids C are alpha / 2, alpha / 2 and beta / 2 respectively. According to the method, the performance under different application conditions can be reasonably optimized, so that wide-angle performance improvement and optimization and balance of overall comprehensive performance can be realized.

Description

Technical Field

[0001] The present invention relates to a manufacturing method of a microprism retroreflective film and its mold using a combination of three triangular pyramids. Background Art

[0002] A widely used triangular pyramid on the market has a structure of a corner cube reflector with an equilateral triangle as the bottom surface and three reflecting surfaces that are 90-degree angles to each other, as Figure 1 shown; another triangular pyramid has a structure of a corner cube reflector with an isosceles triangle as the bottom surface and three reflecting surfaces that are 90-degree angles to each other.

[0003] Currently, there is only one optical design variable for the above microprism retroreflective film, making it difficult to simultaneously improve the retroreflective performance at different incident angles and observation angles (especially wide angles), that is, different azimuth angles, and to balance the retroreflective performance between different incident angles and observation angles (especially wide angles and small incident angles), as well as the balance between the retroreflective performances at different azimuth angles (such as 0 degrees, 90 degrees, 180 degrees).

[0004] In the prior art, in order to obtain the anisotropic uniformity of the retroreflective performance of the retroreflective film at different azimuth angles, four types of nickel molds for retroreflective films usually use two nickel molds for retroreflective films with different orientations of 0 degrees and 90 degrees to mechanically and interactively piece together to manufacture a roller master mold; by slightly adjusting an angle to deviate from the standard corner cube reflector structure, the regulation of the retroreflective performance of the retroreflective film (such as improving the wide-angle performance) is achieved, but the above method is very cumbersome to manufacture and there are mechanical stitching errors, making it difficult to achieve the expected effect.

[0005] In addition, although the microprism retroreflective film using all prisms (3M in the United States) has a 50% higher retroreflective performance than the microprism retroreflective film using triangular pyramids (or the effective reflection area of the triangular pyramid retroreflective film is 66.67% of the effective reflection area of the all-prism retroreflective film), the mold structure of the all-prism retroreflective film (such as Chinese Patent Nos. 2015107772604, 201811202555.9) is very complex, the manufacturing difficulty is very high, and due to the mold manufacturing error, the reflective performance is much lower than expected, thus limiting its popularization and application.

[0006] In view of the above deficiencies, the applicant applied for "Retroreflective Microprism Array Structure and Its Manufacturing Method" (Publication No. CN 117930406 A) in March 2024 and "Microprism Retroreflective Film with a Double Triangular Pyramid Combination Structure and Its Mold Manufacturing Method" (Publication No. CN118759624B) in September 2024 respectively.

[0007] Among them, although the "retroreflective microprism array structure and its manufacturing method" is more convenient for manufacturing compared to patents 2015107772604 and 201811202555.9, it avoids the difficulty of secondary clamping and machining of special-shaped surfaces, and ensures the quality of the finished product. However, when making through holes on the second substrate during the processing procedure, it is necessary to drill holes one by one (as Figure 1 shown), and then process them by wire cutting. The processing procedure is still relatively cumbersome, and each pyramid formed by its processing is a regular triangular pyramid, and the inclination angles of the pyramid surfaces are all the same. There is only one optical design variable for the microprism retroreflective film obtained, and it is difficult to obtain different incident angles and observation angles. That is, such a microprism retroreflective film design can meet the performance requirements of Class IV retroreflective films. When used for Class V retroreflective films, under the conditions of large observation angles and large incident angles, the retroreflective coefficient cannot meet the standard requirements; Among them, the "manufacturing method of a microprism retroreflective film with a double triangular pyramid combination structure and its mold" proposes to use two types of tools with tool design angles of α and β to process a microprism retroreflective film with a double triangular pyramid combination structure on the same mold substrate. After using the first type of tool with a tool angle of α to process the large triangular pyramid, then use the second type of tool with a tool angle of β to process. Adjust the tool orientation according to the design requirements so that the inclination angles of the three pyramid surfaces of the central triangular pyramid are all β / 2. At this time, the inclination angles of the two pyramid surfaces of the corner triangular pyramid are α / 2, and the inclination angle of the third pyramid surface in the middle is β / 2. Although the wide-angle performance of the retroreflective film can be optimized to a certain extent by adjusting the angle variable of the triangular pyramid located in the center, or a certain degree of optimization of the 0-degree and 90-degree performance of the retroreflective film can be obtained, the microprism retroreflective film obtained still has the disadvantage of insufficient freedom in optical design optimization. Summary of the Invention

[0008] In view of the above existing problems, the purpose of the present invention is to propose a manufacturing method of a microprism retroreflective film with a combination of three triangular pyramids and its mold. The manufacturing method of the microprism retroreflective film with a combination of three triangular pyramids and its mold is reasonably designed, can further increase the freedom of optical design, is conducive to optimization design, and obtains better performance indicators under different application conditions.

[0009] The technical solution of the present invention is as follows: The present invention adopts a microprism retroreflective film composed of a combination of three triangular pyramids, which is characterized in that: the surface of the microprism retroreflective film is formed by an array of identical parallelogram unit bodies, and each parallelogram unit body is composed of four identical triangular pyramids A, one triangular pyramid B, and three identical triangular pyramids C. The orientations of the four triangular pyramids A are 180 degrees opposite to those of the three triangular pyramids C and the triangular pyramid B. The three triangular pyramids C and the triangular pyramid B are staggered between the four triangular pyramids A. The bases of the triangular pyramid B and the triangular pyramid C are both identical equilateral triangles. The inclination angles of the three pyramidal faces of each triangular pyramid A are all α / 2, the inclination angles of the pyramidal faces of the triangular pyramid B are all β / 2, and the inclination angles of the three pyramidal faces of the triangular pyramid C are α / 2, α / 2, and β / 2 respectively.

[0010] Preferably, the above-mentioned triangular pyramids A are respectively triangular pyramid A1, triangular pyramid A2, triangular pyramid A3, and triangular pyramid A4, and the above-mentioned triangular pyramids C are respectively triangular pyramid C1, triangular pyramid C2, and triangular pyramid C3. The first row of the parallelogram unit body is sequentially arranged as triangular pyramid A3, triangular pyramid C1, triangular pyramid A4, and triangular pyramid C2. The second row of the parallelogram unit body is sequentially arranged as triangular pyramid A1, triangular pyramid B, triangular pyramid A2, and triangular pyramid C3. The orientations of adjacent triangular pyramids are 180 degrees opposite to each other.

[0011] Preferably, the pyramidal face A101 of the above-mentioned triangular pyramid A1 and the pyramidal face A201 of the triangular pyramid A2 are coplanar, the pyramidal face C101 of the triangular pyramid C1 and the pyramidal face C201 of the triangular pyramid C2 are coplanar, the pyramidal face A102 of the triangular pyramid A1 and the pyramidal face A301 of the triangular pyramid A3 are coplanar, the pyramidal face C301 of the triangular pyramid C3 and the pyramidal face C202 of the triangular pyramid C2 are coplanar, the pyramidal face A202 of the triangular pyramid A2 and the pyramidal face A302 of the triangular pyramid A3 are coplanar, the pyramidal face C302 of the triangular pyramid C3 and the pyramidal face C102 of the triangular pyramid C1 are coplanar, the pyramidal face A303 of the triangular pyramid A3 and the pyramidal face A401 of the triangular pyramid A4 are coplanar, the pyramidal face B001 of the triangular pyramid B and the pyramidal face C303 of the triangular pyramid C3 are coplanar, the pyramidal face B002 of the triangular pyramid B and the pyramidal face C103 of the triangular pyramid C1 are coplanar, and the pyramidal face A203 of the triangular pyramid A2 and the pyramidal face A402 of the triangular pyramid A4 are coplanar.

[0012] Preferably, the above-mentioned α = 70.50 degrees, β = 70.32 degrees, and γ = 0.5 * (α + β) = 70.41 degrees.

[0013] Preferably, the above-mentioned α = 70.50 degrees, β = 70.36 degrees, and γ = 0.5 * (α + β) = 70.43 degrees.

[0014] The manufacturing method of a mold for a microprism retroreflective film composed of a combination of three triangular pyramids according to the present invention is used to manufacture a mold for a microprism retroreflective film composed of a combination of three triangular pyramids as described above, and is characterized in that: The mold substrate is installed on the workbench. The workbench can drive the mold substrate to move along the X-axis and Y-axis in the horizontal direction, and the B-axis turntable on the workbench can drive the mold substrate to rotate around the normal line B-axis of the mold substrate. Above the mold substrate, there is a main shaft parallel to the upper surface of the mold substrate and a fly cutter disk fixedly connected to the main shaft. Tools are installed on the fly cutter disk, and the tools can rotate around the Y-axis driven by the main shaft. The specific manufacturing steps are as follows: Step 1: Rotate the mold substrate on the B-axis turntable by an angle of 0 degrees (or 180 degrees), and use the first type of tool with a tool angle of α installed on the fly cutter disk to machine the two side conical surfaces of the parallelogram unit, namely the conical surface A101 of triangular pyramid A1, the conical surface A201 of triangular pyramid A2, the conical surface C101 of triangular pyramid C1, and the conical surface C201 of triangular pyramid C2, with an inclination angle of α / 2; the first type of tool is a symmetric tool with the same inclination angles on both sides; Step 2: Rotate the mold substrate on the B-axis turntable by an angle of 120 degrees (or 300 degrees), and use the first type of tool with a tool angle of α installed on the fly cutter disk to machine the other two side conical surfaces of the parallelogram unit, namely the conical surface A102 of triangular pyramid A1, the conical surface A301 of triangular pyramid A3, the conical surface C301 of triangular pyramid C3, and the conical surface C202 of triangular pyramid C2, with an inclination angle of α / 2; Step 3: Rotate the mold substrate on the B-axis turntable by an angle of 60 degrees (or 240 degrees), and use the first type of tool with a tool angle of α installed on the fly cutter disk to machine the conical surfaces at two opposite corners of the parallelogram unit (1), that is, the conical surface A202 of triangular pyramid A2, the conical surface A302 of triangular pyramid A3, the conical surface C302 of triangular pyramid C3, and the conical surface C102 of triangular pyramid C1, with an inclination angle of α / 2; Step 4: Rotate the mold substrate on the B-axis turntable by an angle of 0 degrees (or 180 degrees), and replace it with the second type of tool with a tool angle of γ = 0.5 * (α + β) installed on the fly cutter disk to machine and form the conical surface B001 of triangular pyramid B and the conical surface C303 of triangular pyramid C3, with an inclination angle of β / 2; at the same time, form the conical surface A303 of triangular pyramid A3 and the conical surface A401 of triangular pyramid A4, with an inclination angle of α / 2; the second type of tool is an asymmetric tool with an inclination angle of α / 2 on one side and an inclination angle of β / 2 on the other side; Step 5: Rotate the mold substrate on the B-axis turntable by an angle of 120 degrees (or 300 degrees), and use the second type of tool with a tool angle of γ = 0.5 * (α + β) installed on the fly cutter disk to machine and form the conical surface B002 of triangular pyramid B and the conical surface C103 of triangular pyramid C1, with an inclination angle of β / 2; at the same time, form the conical surface A203 of triangular pyramid A2 and the conical surface A402 of triangular pyramid A4, with an inclination angle of α / 2; Step 6: Finally, rotate the mold substrate on the B-axis turntable by an angle of 60 degrees (or 240 degrees), and use the second tool with a tool angle of γ = 0.5*(α + β) installed on the fly cutter head to machine and form the pyramid surface B003 of the triangular pyramid B and the pyramid surface C203 of the triangular pyramid C2, with an inclination angle of β / 2; at the same time, form the pyramid surface A103 of the triangular pyramid A1 and the pyramid surface A403 of the triangular pyramid A4, with an inclination angle of α / 2; Thus, the mold of the microprism reflective film composed of three different triangular pyramid structures, namely, the triangular pyramid A with an inclination angle of α / 2 for each, the triangular pyramid B with an inclination angle of β / 2, and the triangular pyramid C with inclination angles of α / 2, α / 2, and β / 2 respectively, is machined and formed.

[0015] The present invention has the following technical advantages.

[0016] From the perspective of optical design, an increase in the degree of freedom of optical design means that the optical system is expected to simultaneously meet the performance indicators of more different application conditions. For Class V reflective films with high performance requirements, improving their wide-angle performance at large viewing angles and large incident angles, as well as their performance in the 90-degree and 0-degree azimuth orientations and their optimization and balance, have always been the focus of the research and development of Class V reflective film technology; the reflective film of the present invention has three triangular pyramids, namely, the triangular pyramid A with a pyramid surface inclination angle of α / 2, the triangular pyramid B with a pyramid surface inclination angle of β / 2, and the "hybrid" triangular pyramid C with three pyramid surface inclination angles of α / 2, α / 2, and β / 2 respectively; it achieves the design freedom of the three triangular pyramids, and the area ratios of the three triangular pyramids A, B, and C are 50%, 12.5%, and 37.5% respectively, which can reasonably optimize the performance under different application conditions, thereby obtaining an improvement in wide-angle performance that cannot be achieved by the microprism reflective films with traditional triangular pyramid unit structures and double triangular pyramid combination structures, as well as the optimization and balance of the overall comprehensive performance. Description of the Drawings

[0017] The present invention will be further described below with reference to the accompanying drawings; Figure 1 is a three-dimensional view of the structure of the second substrate of the existing reflective microprism; Figure 2 is a three-dimensional schematic diagram of the structure of the parallelogram unit body of the present invention; Figure 3 is Figure 2 the front view of Figure 4 is a three-dimensional schematic diagram of the mold substrate placed on the workbench for processing; Figure 5 is a sectional schematic diagram of the mold substrate processed by the fly cutter tool in the first embodiment; Figure 6 is a three-dimensional schematic diagram of the finished mold of the microprism reflective film of the present invention; Figure 7 isFigure 6 Front view (for intuitive viewing, the reference numerals in the figure correspond one by one Figure 3 to the reference numerals of the reflective film in Figure 8 It is a schematic three-dimensional structure diagram of the mold substrate before processing; Figure 9 is Figure 8 the front view of Figure 10 is Figure 8 the front view of the mold substrate of Figure 11 is Figure 10 the front view of the mold substrate of Figure 12 is Figure 11 the front view of the mold substrate of Figure 13 is Figure 12 the three-dimensional view of Figure 14 is Figure 12 the front view of the mold substrate of Figure 15 is Figure 14 the schematic three-dimensional structure diagram of Figure 16 is Figure 14 the front view of the mold substrate of Figure 17 is Figure 16 the schematic three-dimensional structure diagram of Figure 18 is Figure 16 the front view of the mold substrate of Figure 19 is Figure 18 the schematic three-dimensional structure diagram (i.e., the schematic three-dimensional structure diagram of the finished mold of the present application); Figure 20 is the schematic cross-sectional structure diagram of the mold substrate processed by the flying cutter tool in the second embodiment. Specific embodiments

[0018] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0019] The microprism retroreflective film of the present invention adopts a combination of three triangular pyramids. The surface of the microprism retroreflective film is formed by an array of identical parallelogram unit cells 1. Each parallelogram unit cell 1 is specifically composed of four identical triangular pyramids A, one triangular pyramid B, and three identical triangular pyramids C. Among them, the triangular pyramids A are respectively triangular pyramid A1, triangular pyramid A2, triangular pyramid A3, and triangular pyramid A4, and the triangular pyramids C are respectively triangular pyramid C1, triangular pyramid C2, and triangular pyramid C3. The first row of the parallelogram unit cell is sequentially arranged as triangular pyramid A3, triangular pyramid C1, triangular pyramid A4, and triangular pyramid C2. The second row of the parallelogram unit cell is sequentially arranged as triangular pyramid A1, triangular pyramid B, triangular pyramid A2, and triangular pyramid C3. The orientations of adjacent triangular pyramids are 180 degrees to each other.

[0020] Among them, the orientations of the four triangular pyramids A are 180 degrees to the orientations of the three triangular pyramids C and the triangular pyramid B. The three triangular pyramids C and the triangular pyramid B are staggered between the four triangular pyramids A.

[0021] The bases of the triangular pyramids A, B, and C are all identical equilateral triangles. The inclination angles of the three pyramid faces of each triangular pyramid A are all α / 2, the inclination angle of the pyramid face of the triangular pyramid B is β / 2, and the inclination angles of the three pyramid faces of the triangular pyramid C are α / 2, α / 2, and β / 2 respectively. In one embodiment, α = 70.50 degrees, β = 70.32 degrees, and γ = 0.5 * (α + β) = 70.41 degrees.

[0022] Or, the bases of the triangular pyramids A, B, and C are all identical equilateral triangles. The inclination angles of the three pyramid faces of each triangular pyramid A are all α / 2, the inclination angle of the pyramid face of the triangular pyramid B is γ - α / 2, and the inclination angles of the three pyramid faces of the triangular pyramid C are α / 2, α / 2, and γ - α / 2 respectively. In one embodiment, α = 70.50 degrees, β = 70.36 degrees, and γ = 0.5 * (α + β) = 70.43 degrees.

[0023] The pyramid face A101 of the triangular pyramid A1 and the pyramid face A201 of the triangular pyramid A2 are coplanar. The pyramid face C101 of the triangular pyramid C1 and the pyramid face C201 of the triangular pyramid C2 are coplanar. The pyramid face A102 of the triangular pyramid A1 and the pyramid face A301 of the triangular pyramid A3 are coplanar. The pyramid face C301 of the triangular pyramid C3 and the pyramid face C202 of the triangular pyramid C2 are coplanar. The pyramid face A202 of the triangular pyramid A2 and the pyramid face A302 of the triangular pyramid A3 are coplanar. The pyramid face C302 of the triangular pyramid C3 and the pyramid face C102 of the triangular pyramid C1 are coplanar. The pyramid face A303 of the triangular pyramid A3 and the pyramid face A401 of the triangular pyramid A4 are coplanar. The pyramid face B001 of the triangular pyramid B and the pyramid face C303 of the triangular pyramid C3 are coplanar. The pyramid face B002 of the triangular pyramid B and the pyramid face C103 of the triangular pyramid C1 are coplanar. The pyramid face A203 of the triangular pyramid A2 and the pyramid face A402 of the triangular pyramid A4 are coplanar.

[0024] The processing method of the mold specifically used for manufacturing the aforementioned microprism retroreflective film composed of three triangular pyramids is as follows.

[0025] Example 1, as Figure 4 , 5 shown, the mold substrate K1 is horizontally installed on the workbench K2. The workbench can drive the mold substrate to move along the X-axis and Y-axis in the horizontal direction, and the B-axis turntable on the workbench can drive the mold substrate to rotate around the normal B-axis of the mold substrate. Above the mold substrate, there is a main shaft K3 parallel to the upper surface of the mold substrate and a fly cutter disk K4 fixedly connected to the main shaft. The main shaft K3 can be driven to rotate by existing machine tool equipment. A tool K5 is installed on the fly cutter disk, and the tool can rotate around the Y-axis driven by the main shaft. The specific manufacturing steps are as follows: Step 1: Rotate the mold substrate on the B-axis turntable by an angle of 0 degrees (or 180 degrees) (i.e., Figure 9 shown state), and use the first type of tool with a tool angle of α installed on the fly cutter disk to machine the two side cones of the parallelogram unit body (i.e., Figure 10 the upper and lower side cones, and the workbench drives the mold substrate to move along the X-axis direction during the machining process), that is, the pyramid surface A101 of the triangular pyramid A1, the pyramid surface A201 of the triangular pyramid A2, the pyramid surface C101 of the triangular pyramid C1, and the pyramid surface C201 of the triangular pyramid C2. Their inclination angle is α / 2. The first type of tool is a symmetric tool, and the two side inclination angles are the same, as Figure 10 shown.

[0026] Step 2: Rotate the mold substrate on the B-axis turntable by an angle of 120 degrees (or 300 degrees) (i.e., rotate counterclockwise by 120 degrees (or 300 degrees) around the center in the Figure 9 shown state), and use the first type of tool with a tool angle of α installed on the fly cutter disk to machine the other two side cones of the parallelogram unit body (i.e., Figure 11 the left and right side cones, and the workbench drives the mold substrate to move along the X-axis direction during the machining process), that is, the pyramid surface A102 of the triangular pyramid A1, the pyramid surface A301 of the triangular pyramid A3, the pyramid surface C301 of the triangular pyramid C3, and the pyramid surface C202 of the triangular pyramid C2. Their inclination angle is also α / 2, as Figure 11 shown.

[0027] Step 3: Rotate the mold substrate on the B-axis turntable by an angle of 60 degrees (or 240 degrees) (i.e., rotate counterclockwise by 60 degrees (or 240 degrees) around the center in the Figure 9 shown state), and use the first type of tool with a tool angle of α installed on the fly cutter disk to machine the two diagonal cones of the parallelogram unit body 1, that is, the pyramid surface A202 of the triangular pyramid A2, the pyramid surface A302 of the triangular pyramid A3, the pyramid surface C302 of the triangular pyramid C3, and the pyramid surface C102 of the triangular pyramid C1. Their inclination angle is also α / 2, asFigure 12 , 13 as shown

[0028] Step 4: Rotate the mold substrate on the B-axis turntable by an angle of 0 degrees (or 180 degrees) (i.e., Figure 9 the state shown), replace the tool on the fly cutter head with the second type of tool with a tool angle of γ = 0.5*(α + β) to machine and form the pyramid surface B001 of triangular pyramid B and the pyramid surface C303 of triangular pyramid C3, with an inclination angle of β / 2; at the same time, form the pyramid surface A303 of triangular pyramid A3 and the pyramid surface A401 of triangular pyramid A4, with an inclination angle of α / 2. The second type of tool is an asymmetric tool, with an inclination angle of α / 2 on one side and an inclination angle of β / 2 on the other side, as Figure 14 , 15 shown

[0029] Step 5: Rotate the mold substrate on the B-axis turntable by an angle of 120 degrees (or 300 degrees), use the second type of tool with a tool angle of γ = 0.5*(α + β) installed on the fly cutter head to machine and form the pyramid surface B002 of triangular pyramid B and the pyramid surface C103 of triangular pyramid C1, with an inclination angle of β / 2; at the same time, form the pyramid surface A203 of triangular pyramid A2 and the pyramid surface A402 of triangular pyramid A4, with an inclination angle of α / 2, as Figure 16 , 17 shown

[0030] Step 6: Finally, rotate the mold substrate on the B-axis turntable by an angle of 60 degrees (or 240 degrees), use the second type of tool with a tool angle of γ = 0.5*(α + β) installed on the fly cutter head to machine and form the pyramid surface B003 of triangular pyramid B and the pyramid surface C203 of triangular pyramid C2, with an inclination angle of β / 2; at the same time, form the pyramid surface A103 of triangular pyramid A1 and the pyramid surface A403 of triangular pyramid A4, with an inclination angle of α / 2, as Figure 18 , 19 shown, Figure 18 , 19 that is, the schematic diagram of the structure of the mold product of this application, Figure 18 , 19 is the same as Figure 7 , 8 They are all schematic diagrams of the structure of the mold for manufacturing the reflective film of this application. The shape and size of the mold obtained by the above method are the same as those of the reflective film formed by the subsequent manufacture of this mold. For the convenience of visual inspection, therefore Figure 7 each label in Figure 2 uses the same label as to reflect the one-to-one correspondence between the mold and the reflective film.

[0031] So far, the mold of the microprism retroreflective film composed of three different triangular pyramid structures, namely triangular pyramid A with an inclination angle of α / 2, triangular pyramid B with an inclination angle of β / 2, and triangular pyramid C with inclination angles of α / 2, α / 2, and β / 2 respectively, is processed and formed.

[0032] Specific processing example of Embodiment 1: The tool angle α of the first tool is 70.50 degrees; the asymmetric tool with the tool angle γ of the second tool being 70.41 degrees has an inclination angle of 35.25 degrees on one side and 35.16 degrees on the other side. During processing, first use the α tool and perform array machining according to the B-axis rotation angles of 0 degrees (or 180 degrees), 60 degrees (or 240 degrees), and 120 degrees (or 300 degrees) and an intercept of 0.433 mm. The first to third cuts form a large triangular pyramid table (side length 500 microns, referring to the aforementioned steps 1-3 and Figures 9 - 13 ), and then use the second tool angle to perform array machining along the center line connection of the large triangular pyramid table edges. The fourth to sixth cuts form a composite microprism retroreflective film composed of a parallelogram unit array (referring to the aforementioned steps 4-6 and Figures 14 - 19 ). Each parallelogram unit contains eight triangular pyramid microprism retroreflective films with three reflective surfaces with a side length of 250 μm, and the three reflective surfaces are composed of three different combinations of two inclination angles.

[0033] Embodiment 2, as shown in Figure 4 、 Figure 20 The mold base material K1 is horizontally and fixedly installed on the workbench K2. The workbench can drive the mold base material to move along the X-axis and Y-axis in the horizontal direction, and the B-axis turntable on the workbench can drive the mold base material to rotate around the normal B-axis of the mold base material. Above the mold base material, there is a main shaft K3 and a fly cutter head K4 fixedly connected to the main shaft. The main shaft K3 can be driven to rotate by existing machine tool equipment. A tool K5 is installed on the fly cutter head, and the tool can rotate around the Y-axis driven by the main shaft. The specific steps during manufacturing are as follows: Step 1: Rotate the mold base material on the B-axis turntable to an angle of 0 degrees (or 180 degrees) (i.e., the state shown in Figure 9 ), and use the first tool with a tool angle of α installed on the fly cutter head to machine the two side cone surfaces of the parallelogram unit body (i.e., the upper and lower side cone surfaces of Figure 10 ). During the machining process, the workbench drives the mold base material to move along the X-axis direction), that is, the cone surface A101 of triangular pyramid A1, the cone surface A201 of triangular pyramid A2, the cone surface C101 of triangular pyramid C1, and the cone surface C201 of triangular pyramid C2, with an inclination angle of α / 2, as shown in Figure 10 . For example, the tool angle α of the first tool is 70.50 degrees.

[0034] Step 2: Rotate the mold base material on the B-axis turntable to an angle of 120 degrees (or 300 degrees) (i.e., with Figure 9Rotate counterclockwise 120 degrees (or 300 degrees) around the center in the state shown, and use the first type of tool with a tool angle of α installed on the fly cutter head to machine the other two tapered surfaces of the parallelogram unit body (that is, Figure 11 the left and right tapered surfaces, and the workbench drives the die substrate to move along the X-axis direction during the machining process), that is, the tapered surface A102 of the triangular pyramid A1, the tapered surface A301 of the triangular pyramid A3, the tapered surface C301 of the triangular pyramid C3, and the tapered surface C202 of the triangular pyramid C2, and their inclination angles are also α / 2, as Figure 11 shown.

[0035] Step 3: Rotate the die substrate on the B-axis turntable by an angle of 60 degrees (or 240 degrees) (that is, Figure 9 rotate counterclockwise 60 degrees (or 240 degrees) around the center in the state shown, and use the first type of tool with a tool angle of α installed on the fly cutter head to machine the tapered surfaces of the two opposite corners of the parallelogram unit body 1, that is, the tapered surface A202 of the triangular pyramid A2, the tapered surface A302 of the triangular pyramid A3, the tapered surface C302 of the triangular pyramid C3, and the tapered surface C102 of the triangular pyramid C1, and their inclination angles are also α / 2, as Figure 12 、 13 shown.

[0036] Step 4: Replace the tool on the fly cutter head of the working spindle with the second type of tool with a tool angle of γ, and adjust the tool to generate a deflection angle △, that is, the symmetric center plane of the second type of tool forms a deflection angle △ with the normal plane of the die substrate, as Figure 20 shown; make the inclination angle of one side edge of the tool angle be γ / 2 + △ = α / 2, and the inclination angle of the other side edge be γ / 2 - △ = γ - α / 2 = β / 2. For example, for the first type of tool with a tool angle α = 70.50 degrees and the second tool being a symmetric tool with γ = 70.43 degrees, by adjusting the tool deflection angle △ = 0.035 degrees, the inclination angle of one side of the tool is 35.25 degrees, and the inclination angle of the other side is 35.18 degrees; on the basis of the structure machined in Step 3, rotate the die substrate to the position at 0 degrees (or 180 degrees) (that is, Figure 9 the position shown), and then use the adjusted second type of tool to machine and form the tapered surface B001 of the triangular pyramid B and the tapered surface C303 of the triangular pyramid C3, and their inclination angle is γ - α / 2; at the same time, form the tapered surface A303 of the triangular pyramid A3 and the tapered surface A401 of the triangular pyramid A4, and their inclination angle is α / 2; as Figure 14 、 15 shown.

[0037] Step 5: Rotate the die substrate to 120 degrees (or 300 degrees) in sequence, and use the aforementioned adjusted second type of tool to machine and form the tapered surface B002 of the triangular pyramid B and the tapered surface C103 of the triangular pyramid C1, and their inclination angle is γ - α / 2, and at the same time, form the tapered surface A203 of the triangular pyramid A2 and the tapered surface A402 of the triangular pyramid A4, and their inclination angle is α / 2, as Figure 16, 17 as shown.

[0038] Step 6: Finally, rotate the mold substrate sequentially by 60 degrees (or 240 degrees), and use the aforementioned adjusted second type of tool to machine and form the pyramid surface B003 of triangular pyramid B and the pyramid surface C203 of triangular pyramid C2, with an inclination angle of γ - α / 2; at the same time, form the pyramid surface A103 of triangular pyramid A1 and the pyramid surface A403 of triangular pyramid A4, with an inclination angle of α / 2, as Figure 18 , 19 shown, Figure 18 , 19 that is, the structural schematic diagram of the finished mold of the present application, Figure 18 , 19 and Figure 6 , 7 are the same. They are all structural schematic diagrams of the molds for making the reflective film of the present application. The shape and size of the mold obtained by the above method are the same as those of the reflective film formed subsequently by this mold. For the convenience of intuitive viewing, therefore Figure 7 each label in Figure 2 uses the same label as that in

[0039] to reflect the one-to-one correspondence between the mold and the reflective film. Figure 18 , 19 shown.

[0040] Example 2 Specific processing example: The tool angle α of the first type of tool is 70.50 degrees; the second type of tool is a symmetric tool with γ = 70.43 degrees. By adjusting the tool deflection angle △ = 0.035 degrees, the inclination angle of one side of the tool is 35.25 degrees, and the inclination angle of the other side is 35.18 degrees; during processing, first use the α tool and perform array processing according to the rotation angles of the B axis being 0 degrees (or 180 degrees), 60 degrees (or 240 degrees), and 120 degrees (or 300 degrees), and the intercept being 0.433 mm. The first to third cuts in the processing form a large triangular pyramid frustum (side length 500 microns). Then, use the second type of tool to perform array processing along the center line connection of the large triangular pyramid frustum edges respectively. The fourth to sixth cuts in the processing form a composite microprism reflective film composed of a parallelogram unit array. Each parallelogram unit contains 8 triangular pyramid microprism reflective films with three reflective surfaces with side lengths of 250 μm and composed of two inclination angles combined into three different types.

[0041] In order to verify the significant advantages of the above embodiments of the present application, a comparative example is provided below: The tool of this comparative example has a tool angle α = 70.50 degrees, and the side length of the triangular pyramid is 250 μm. According to the rotation angle of the B-axis, it is 0 degrees (or 180 degrees), 60 degrees (or 240 degrees), and 120 degrees (or 300 degrees) respectively, and the intercept is 216.5 μm. An array machining is performed to form a conventional triangular pyramid microprism retroreflective film composed of an array of the same parallelogram units. Each parallelogram unit is composed of 2 identical triangular pyramids.

[0042] Comparison of the retroreflective performance test data of 3 samples:

[0043] Description of technical advantages: The comparative example is a conventional triangular pyramid microprism retroreflective film, and its retroreflective performance is mainly distributed at a small observation angle of 0.2 degrees. It cannot meet the requirements of Class V (V class) standards under the test conditions of an incident angle of 30 degrees, observation angles of 0.5 degrees and 1 degree, and observation angles of 1 degree, incident angles of -4 degrees and 15 degrees; the microprism retroreflective film prepared by the present invention is composed of three different triangular pyramids, which optimizes and improves the retroreflective performance under the test conditions of large observation angles and large incident angles, so that the retroreflective performance under all test conditions meets the requirements of Class V standards.

[0044] The mold obtained by the above processing is further processed by the existing conventional technical means to obtain a retroreflective film (which is the prior art and will not be repeated here).

[0045] In addition, samples (or retroreflective film samples) prepared by using different tools and processing methods can also be used for performance detection to verify and compare the performance of the mold or retroreflective film obtained by the technical solution of the present application.

[0046] The specific different tools and processing methods are as follows: 1. Use the first tool with a tool angle of α to independently process and detect a microprism retroreflective film sample with a triangular pyramid unit structure having a pyramid surface inclination angle of α / 2.

[0047] 2. Use the third tool with a tool angle of β to independently process and detect a microprism retroreflective film sample with a triangular pyramid unit structure having a pyramid surface inclination angle of β / 2.

[0048] 3. Use the first tool with a tool angle of α to process two pyramid surfaces of the triangular pyramid, and then use the third tool with a tool angle of β to process the third pyramid surface of the triangular pyramid, so as to form a "composite cone surface" triangular pyramid retroreflective film sample and detect it.

[0049] Among the three triangular pyramid retroreflective film samples obtained by the above three processing methods, the bottom shape dimensions of each triangular pyramid unit are the same as those of a single triangular pyramid in this application. The difference lies in the different pyramid surfaces. The three triangular pyramid retroreflective film samples obtained by the three processing methods have a single optical design variable, and it is difficult to obtain different incident angles and observation angles (especially wide angles), and their performance is lower than or close to that of Class V retroreflective films.

[0050] In addition, for the "Manufacturing Method of a Microprism Retroreflective Film with a Double Triangular Pyramid Composite Structure and Its Mold" (Patent Publication No. CN118759624B), after machining the large triangular pyramid with the first tool with a tool angle of α, the second tool with a tool angle of β is used for machining (a total of 6 machining steps). Although the wide-angle performance of the retroreflective film can be optimized to a certain extent by adjusting the angle variable of the triangular pyramid at the center, or a certain degree of optimization of the performance at 0 degrees and 90 degrees of the retroreflective film can be obtained, under the same machining steps (this application also has 6 machining steps and 6 steps), although the microprism retroreflective film obtained by this patent has two degrees of freedom in the design of triangular pyramids, there is still a lack of freedom in optical design optimization.

[0051] This application has three triangular pyramids: a triangular pyramid A with a pyramid surface inclination angle of α / 2, a triangular pyramid B with a pyramid surface inclination angle of β / 2, and a "hybrid" triangular pyramid C with three pyramid surface inclination angles of α / 2, α / 2, and β / 2 respectively. It achieves three degrees of freedom in the design of triangular pyramids. The area ratios of the three triangular pyramids A, B, and C are 50%, 12.5%, and 37.5% respectively, which can further reasonably optimize the performance under different application conditions, thereby achieving an improvement in wide-angle performance that cannot be achieved by the microprism retroreflective film with the traditional triangular pyramid unit structure and the double triangular pyramid composite structure, as well as the optimization and balance of the overall comprehensive performance.

[0052] In summary, the present invention has the following technical advantages.

[0053] From the perspective of optical design, an increase in the degree of freedom of optical design means that the optical system is expected to simultaneously meet the performance indicators of more different application conditions. For Class V retroreflective films with high performance requirements, improving their wide-angle performance at large viewing angles and large incident angles, the performance in the 90-degree and 0-degree azimuth orientations, and their optimization and balance have always been the focus of the research and development of Class V retroreflective film technology; the retroreflective film of the present invention has a triangular pyramid A with a pyramid surface inclination angle of α / 2, a triangular pyramid B with a pyramid surface inclination angle of β / 2, and a "hybrid" triangular pyramid C with three pyramid surface inclination angles of α / 2, α / 2, and β / 2 respectively; it achieves the design freedom of three triangular pyramids, and the area ratios of the three triangular pyramids A, triangular pyramid B, and triangular pyramid C are 50%, 12.5%, and 37.5% respectively, which can reasonably optimize the performance under different application conditions, so as to obtain an improvement in wide-angle performance that cannot be achieved by the microprism retroreflective film with the traditional triangular pyramid unit structure and the double triangular pyramid combination structure, as well as the optimization and balance of the overall comprehensive performance.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: it is still possible to modify the specific implementation manners of the present invention or perform equivalent replacements for some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. A microprismatic retroreflective film using a combination of three triangular pyramids, characterized in that: The surface of the microprism retroreflective film is formed by an array of identical parallelogram unit bodies (1). Each parallelogram unit body (1) is composed of four identical triangular pyramids A, one triangular pyramid B, and three identical triangular pyramids C. The orientations of the four triangular pyramids A are 180 degrees opposite to those of the three triangular pyramids C and the triangular pyramid B. The three triangular pyramids C and the triangular pyramid B are staggered between the four triangular pyramids A. The bases of the triangular pyramid B and the triangular pyramid C are both identical equilateral triangles. The inclination angles of the three pyramidal faces of each triangular pyramid A are all α / 2, the inclination angles of the pyramidal faces of the triangular pyramid B are all β / 2, and the inclination angles of the three pyramidal faces of the triangular pyramid C are α / 2, α / 2, and β / 2 respectively.

2. The microprism retroreflective film using a combination of three triangular pyramids according to claim 1, characterized in that: The triangular pyramids A are respectively triangular pyramid A1, triangular pyramid A2, triangular pyramid A3, and triangular pyramid A4. The triangular pyramids C are respectively triangular pyramid C1, triangular pyramid C2, and triangular pyramid C3. In the first row of the parallelogram unit body (1), they are arranged in sequence as triangular pyramid A3, triangular pyramid C1, triangular pyramid A4, and triangular pyramid C2. In the second row of the parallelogram unit body (1), they are arranged in sequence as triangular pyramid A1, triangular pyramid B, triangular pyramid A2, and triangular pyramid C3. The orientations of adjacent triangular pyramids are 180 degrees opposite to each other.

3. The microprism retroreflective film using a combination of three triangular pyramids according to claim 2, wherein: The pyramidal face A101 of the triangular pyramid A1 and the pyramidal face A201 of the triangular pyramid A2 are coplanar. The pyramidal face C101 of the triangular pyramid C1 and the pyramidal face C201 of the triangular pyramid C2 are coplanar. The pyramidal face A102 of the triangular pyramid A1 and the pyramidal face A301 of the triangular pyramid A3 are coplanar. The pyramidal face C301 of the triangular pyramid C3 and the pyramidal face C202 of the triangular pyramid C2 are coplanar. The pyramidal face A202 of the triangular pyramid A2 and the pyramidal face A302 of the triangular pyramid A3 are coplanar. The pyramidal face C302 of the triangular pyramid C3 and the pyramidal face C102 of the triangular pyramid C1 are coplanar. The pyramidal face A303 of the triangular pyramid A3 and the pyramidal face A401 of the triangular pyramid A4 are coplanar. The pyramidal face B001 of the triangular pyramid B and the pyramidal face C303 of the triangular pyramid C3 are coplanar. The pyramidal face B002 of the triangular pyramid B and the pyramidal face C103 of the triangular pyramid C1 are coplanar. The pyramidal face A203 of the triangular pyramid A2 and the pyramidal face A402 of the triangular pyramid A4 are coplanar.

4. The microprismatic retroreflective film using a combination of three triangular pyramids according to claim 3, characterized in that: The α = 70.50 degrees, β = 70.32 degrees, and γ = 0.5 * (α + β) = 70.41 degrees.

5. The microprism retroreflective film using a combination of three triangular pyramids according to claim 3, characterized in that: The α = 70.50 degrees, β = 70.36 degrees, and γ = 0.5 * (α + β) = 70.43 degrees.

6. A manufacturing method for a mold of a microprism retroreflective film using a combination of three types of triangular pyramids, which is used to manufacture the mold of the microprism retroreflective film using a combination of three types of triangular pyramids as described in any one of claims 1, 2, 3, or 4. The characteristics are as follows: The mold substrate is installed on the workbench. The workbench can drive the mold substrate to move along the X-axis and Y-axis in the horizontal direction, and the B-axis turntable on the workbench can drive the mold substrate to rotate around the normal B-axis of the mold substrate. Above the mold substrate, there is a main shaft parallel to the upper surface of the mold substrate and a fly cutter head fixedly connected to the main shaft. A cutter is installed on the fly cutter head. The cutter can rotate around the Y-axis driven by the main shaft. The specific manufacturing steps are as follows: Step 1: Rotate the mold substrate on the B-axis turntable by an angle of 0 degrees, and use the first type of tool with a tool angle of α installed on the fly cutter head to machine the two tapered surfaces of the parallelogram unit body (1), namely, the tapered surface A101 of the triangular pyramid A1, the tapered surface A201 of the triangular pyramid A2, the tapered surface C101 of the triangular pyramid C1, and the tapered surface C201 of the triangular pyramid C2. The inclination angle is α / 2. The first type of tool is a symmetric tool with the same inclination angles on both sides. Step 2: Rotate the mold substrate on the B-axis turntable by an angle of 120 degrees, and use the first type of tool with a tool angle of α installed on the fly cutter head to machine the other two tapered surfaces of the parallelogram unit body (1), namely, the tapered surface A102 of the triangular pyramid A1, the tapered surface A301 of the triangular pyramid A3, the tapered surface C301 of the triangular pyramid C3, and the tapered surface C202 of the triangular pyramid C2. The inclination angle is also α / 2. Step 3: Rotate the mold substrate on the B-axis turntable by an angle of 60 degrees, and use the first type of tool with a tool angle of α installed on the fly cutter head to machine the tapered surfaces at the two opposite corners of the parallelogram unit body (1), that is, the tapered surface A202 of the triangular pyramid A2, the tapered surface A302 of the triangular pyramid A3, the tapered surface C302 of the triangular pyramid C3, and the tapered surface C102 of the triangular pyramid C1. The inclination angle is also α / 2. Step 4: Rotate the mold substrate on the B-axis turntable by an angle of 0 degrees, replace the tool, and use the second type of tool with a tool angle of γ = 0.5*(α + β) installed on the fly cutter head to machine and form the tapered surface B001 of the triangular pyramid B and the tapered surface C303 of the triangular pyramid C3. The inclination angle is β / 2; at the same time, form the tapered surface A303 of the triangular pyramid A3 and the tapered surface A401 of the triangular pyramid A4. The inclination angle is α / 2. The second type of tool is an asymmetric tool with an inclination angle of α / 2 on one side and an inclination angle of β / 2 on the other side. Step 5: Rotate the mold substrate on the B-axis turntable by an angle of 120 degrees, and use the second type of tool with a tool angle of γ = 0.5*(α + β) installed on the fly cutter head to machine and form the tapered surface B002 of the triangular pyramid B and the tapered surface C103 of the triangular pyramid C1. The inclination angle is β / 2; at the same time, form the tapered surface A203 of the triangular pyramid A2 and the tapered surface A402 of the triangular pyramid A4. The inclination angle is α / 2. Step 6: Finally, rotate the mold substrate on the B-axis turntable by an angle of 60 degrees, and use the second type of tool with a tool angle of γ = 0.5*(α + β) installed on the fly cutter head to machine and form the tapered surface B003 of the triangular pyramid B and the tapered surface C203 of the triangular pyramid C2. The inclination angle is β / 2; at the same time, form the tapered surface A103 of the triangular pyramid A1 and the tapered surface A403 of the triangular pyramid A4. The inclination angle is α / 2. So far, the mold of the microprism retroreflective film composed of three different triangular pyramid structures, namely, each triangular pyramid A with an inclination angle of α / 2, the triangular pyramid B with an inclination angle of β / 2, and each triangular pyramid C with inclination angles of α / 2, α / 2, and β / 2 respectively, is machined and formed.

7. The manufacturing method of the mold for the microprism retroreflective film using the combination of three triangular pyramids according to claim 6, characterized in that: The first type of cutting tool has a cutting edge angle α = 70.50 degrees; the second type of cutting tool is an asymmetric cutting tool with a cutting edge angle γ = 70.41 degrees, one side inclination angle is 35.25 degrees, and the other side inclination angle is 35.16 degrees; during processing, the α cutting tool is used first, and it is processed by arraying according to the rotation angles of the B-axis being 0 degrees, 60 degrees, and 120 degrees respectively, with an intercept of 0.433 mm. The first to third cuts of the processing form a large triangular pyramid frustum, and the side length of the large triangular pyramid frustum is 500 microns. Then, the second type of cutting tool edge angle is used to process by arraying along the center connection line of the edges of the large triangular pyramid frustum respectively. The fourth to sixth cuts of the processing form a composite microprism reflective film composed of an array of parallelogram units. Each parallelogram unit contains 8 triangular pyramid microprism reflective films with side lengths of 250 μm, and the three reflective surfaces of each are composed of three different combinations of two inclination angles.

8. A microprism retroreflective film using a combination of three triangular pyramids, characterized in that: The surface of the microprism reflective film is formed by arraying the same parallelogram unit bodies (1). Each parallelogram unit body (1) is composed of four identical triangular pyramids A, one triangular pyramid B, and three identical triangular pyramids C. The orientations of the four triangular pyramids A are 180 degrees with respect to the orientations of the three triangular pyramids C and the triangular pyramid B. The three triangular pyramids C and the triangular pyramid B are staggered between the four triangular pyramids A; the bases of the triangular pyramid B and the triangular pyramid C are both the same equilateral triangle. The inclination angles of the three pyramid faces of each triangular pyramid A are all α / 2, the inclination angle of the pyramid face of the triangular pyramid B is γ - α / 2, and the inclination angles of the three pyramid faces of the triangular pyramid C are α / 2, α / 2, and γ - α / 2 respectively; the triangular pyramids A are respectively triangular pyramid A1, triangular pyramid A2, triangular pyramid A3, and triangular pyramid A4, and the triangular pyramids C are respectively triangular pyramid C1, triangular pyramid C2, and triangular pyramid C3. The first row of the parallelogram unit body (1) is arranged in sequence as triangular pyramid A3, triangular pyramid C1, triangular pyramid A4, and triangular pyramid C2. The second row of the parallelogram unit body (1) is arranged in sequence as triangular pyramid A1, triangular pyramid B, triangular pyramid A2, and triangular pyramid C3. The orientations of adjacent triangular pyramids are 180 degrees with respect to each other.

9. A manufacturing method of a mold for a microprism reflective film using a combination of three triangular pyramids, which is used to manufacture the mold for the microprism reflective film using a combination of three triangular pyramids as described in claim 8, and is characterized in that: The mold substrate (K1) is horizontally installed on the workbench (K2). The workbench can drive the mold substrate to move along the X-axis and Y-axis in the horizontal direction, and the B-axis turntable on the workbench can drive the mold substrate to rotate around the normal B-axis of the mold substrate. Above the mold substrate, there is a main shaft (K3) parallel to the upper surface of the mold substrate and a fly cutter disk (K4) fixedly connected to the main shaft. A cutting tool (K5) is installed on the fly cutter disk, and the cutting tool can rotate around the Y-axis driven by the main shaft. The specific manufacturing steps are as follows: Step 1: Rotate the mold substrate on the B-axis turntable by an angle to 0 degrees, and use the first type of tool with a tool angle of α installed on the fly cutter head to machine the two side conical surfaces of the parallelogram unit body, namely the conical surface A101 of the triangular pyramid A1, the conical surface A201 of the triangular pyramid A2, the conical surface C101 of the triangular pyramid C1, and the conical surface C201 of the triangular pyramid C2. Their inclination angle is α / 2. The first type of tool is a symmetric tool, and the inclination angles on both sides are the same; Step 2: Rotate the mold substrate on the B-axis turntable by an angle to 120 degrees, and use the first type of tool with a tool angle of α installed on the fly cutter head to machine the other two side conical surfaces of the parallelogram unit body, namely the conical surface A102 of the triangular pyramid A1, the conical surface A301 of the triangular pyramid A3, the conical surface C301 of the triangular pyramid C3, and the conical surface C202 of the triangular pyramid C2. Their inclination angle is also α / 2; Step 3: Rotate the mold substrate on the B-axis turntable by an angle to 60 degrees, and use the first type of tool with a tool angle of α installed on the fly cutter head to machine the conical surfaces at two opposite corners of the parallelogram unit body (1), that is, the conical surface A202 of the triangular pyramid A2, the conical surface A302 of the triangular pyramid A3, the conical surface C302 of the triangular pyramid C3, and the conical surface C102 of the triangular pyramid C1. Their inclination angle is also α / 2; Step 4: Replace the tool on the fly cutter head with the second type of tool with a tool angle of γ, and adjust the tool to generate a deflection angle △, that is, the symmetric center plane of the second type of tool forms a deflection angle △ with the normal plane of the mold substrate. △ is not zero, so that the inclination angle of one side edge of the tool angle is γ / 2 + △ = α / 2, and the inclination angle of the other side edge is γ / 2 - △ = γ - α / 2 = β / 2; On the basis of the structure processed in Step 3, rotate the mold substrate to the 0-degree position, and then use the adjusted second type of tool to machine and form the conical surface B001 of the triangular pyramid B and the conical surface C303 of the triangular pyramid C3. Their inclination angle is γ - α / 2; At the same time, form the conical surface A303 of the triangular pyramid A3 and the conical surface A401 of the triangular pyramid A4. Their inclination angle is α / 2; Step 5: Rotate the mold substrate to 120 degrees in sequence, and use the aforementioned adjusted second type of tool to machine and form the conical surface B002 of the triangular pyramid B and the conical surface C103 of the triangular pyramid C1. Their inclination angle is γ - α / 2. At the same time, form the conical surface A203 of the triangular pyramid A2 and the conical surface A402 of the triangular pyramid A4. Their inclination angle is α / 2; Step 6: Rotate the mold substrate to 60 degrees in sequence again, and use the aforementioned adjusted second type of tool to machine and form the conical surface B003 of the triangular pyramid B and the conical surface C203 of the triangular pyramid C2. Their inclination angle is γ - α / 2; At the same time, form the conical surface A103 of the triangular pyramid A1 and the conical surface A403 of the triangular pyramid A4. Their inclination angle is α / 2; So far, the mold of the microprism reflective film composed of three different triangular pyramid structures, namely, the triangular pyramid A with an inclination angle of α / 2 for each, the triangular pyramid B with an inclination angle of γ - α / 2, and the triangular pyramid C with inclination angles of α / 2, α / 2, and γ - α / 2 respectively, is machined and formed.

10. The manufacturing method of the mold of the microprism reflective film using the combination of three triangular pyramids according to claim 9, characterized in that: The tool angle α of the first tool is 70.50 degrees; the second tool is a symmetric tool with γ = 70.43 degrees. By adjusting the tool deflection angle △ = 0.035 degrees, the inclination angle of one side of the tool is 35.25 degrees, and the inclination angle of the other side is 35.18 degrees. When processing, first use the first tool and perform fixed-intercept array machining according to the B-axis rotation angles of 0 degrees, 60 degrees, and 120 degrees. The first to third cuts form a large triangular pyramid frustum. Then, use the second tool to perform array machining along the center line connection of the edges of the large triangular pyramid frustum. The fourth to sixth cuts form a composite microprism reflective film composed of a parallelogram unit array.

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