TW201910110A - Method for manufacturing Fresnel lens and injection molding mold apparatus for Fresnel lens capable of preventing the plastic material from being locally cooled and solidified and improving the optical quality of the Fresnel lens finished product - Google Patents

Abstract

A method for manufacturing a Fresnel lens includes a rapid heating step, an injection step, a transfer printing step, and a rapid cooling molding step. The rapid heating step includes injecting a high temperature fluid into at least one mold water passage in a Fresnel lens injection molding mold apparatus for rapid heating the thermoplastic material to a flowable temperature. The rapid cooling molding step is to inject a low temperature fluid instead into the mold water passage in the Fresnel lens injection molding mold apparatus for rapidly cooling the liquid thermoplastic material in the mold cavity and making the material cooled and solidified into a Fresnel lens. The injection molding mold apparatus can be uniformly and rapidly heated and cooled via the mold water passage, thereby preventing the plastic material from being locally cooled and solidified and improving the optical quality of the Fresnel lens finished product.

Description

Method for manufacturing Fresnel lens, Fresnel lens injection molding device and Fresnel lens thereof

The invention relates to a lens manufacturing method, in particular to a method for manufacturing a Fresnel lens, a Fresnel lens injection molding device and a Fresnel lens thereof. The manufacturing method enables the plastic material to be sufficiently filled into the cavity in the mold by performing a quenching and heat treatment process on the thermoplastic plastic material, so that the manufactured Fresnel lens is produced on the tip end of the sawtooth portion and in the groove. The structure is sharp enough and the surface of the Fresnel lens has a high-gloss mirror effect, thereby enhancing the optical quality of the Fresnel lens.

Fresnel lenses, also known as threaded lenses, are characterized by a short focal length and are more material and lighter than conventional lenses. Compared to earlier lens designs, the Fresnel lens is thinner and therefore delivers more light, so that after the source is refracted through the Fresnel lens, the light is more efficiently directed into the distance.

Fresnel lenses are widely used in lighthouse projection navigation lights, projection projector lenses, rear projection display screens, and automotive headlights.

Most of today's optical lenses are made by injection molding with a mold. Traditional Fresnel lenses are mainly produced by this method. In general, Fresnel lenses are processed by an injection molding machine. . However, in the existing Fresnel lens mold, the temperature of the mold is slow, the temperature of each part of the mold is uneven, and the speed of the thermoplastic plastic flowing in the cavity of the mold is different, so the molding cycle is too long, which leads to the injection molding process. It is easy to produce defect flow marks and gas lines on the surface of the Fresnel lens, and finally the surface of the Fresnel lens cannot achieve the effect of sufficiently high-gloss mirror surface. In addition, due to the uneven temperature during processing of various parts of the mold, the lower temperature plastic material is first cooled and formed, resulting in a short shot of the Fresnel lens which is insufficiently filled, and this type of short shot The interior of the defective Fresnel lens is also accompanied by the problem of stress buildup, which in turn affects optical imaging and seriously affects the quality of the Fresnel lens.

Referring to FIG. 18, the conventional Fresnel lens 90 having a short-shot defect has a 15x optical magnification due to insufficient filling of the plastic material at the tip end 91 of the serration portion of the cross section and the groove 92 between the adjacent serrations. The magnification of the electron microscope has been rounded and blunt, rather than ideally sharp.

Up to now, the industry has not produced a sawtooth portion and a groove having a sharp Fresnel lens under an electron microscope exceeding 15 times optical magnification by any processing method.

The present inventors have in view of the conventional injection molding machine for manufacturing Fresnel lenses and the processing method in which the cavity is partially filled due to uneven heat and cold in various parts of the mold during the injection molding process, resulting in the sharpness of the serrated portion of the Fresnel lens product. Insufficient and affecting optical quality and other shortcomings, improving its deficiency and lack, and creating a Fresnel lens manufacturing method, its Fresnel lens injection molding device and its Fresnel lens.

SUMMARY OF THE INVENTION A primary object of the present invention is to provide a method for producing a Fresnel lens, a Fresnel lens injection molding apparatus, and a Fresnel lens thereof. The manufacturing method enables the plastic material to be sufficiently filled into the cavity in the mold by performing a quenching and heat treatment process on the thermoplastic plastic material, so that the manufactured Fresnel lens is produced on the tip end of the sawtooth portion and in the groove. The structure is sharp enough and the surface of the Fresnel lens has a high-gloss mirror effect, thereby enhancing the optical quality of the Fresnel lens.

To achieve the above object, the method for manufacturing the aforementioned Fresnel lens comprises: a rapid heating step of injecting a high-heat fluid into at least one mold water path in a Fresnel lens injection molding apparatus for rapid heating to a thermoplastic plastic material flowable a step of injecting a liquid thermoplastic material into a cavity in the Fresnel lens injection molding apparatus; and a transfer step of pressurizing the liquid thermoplastic material in the cavity with at least one pair of molds To produce a Fresnel lens structure in the thermoplastic plastic material; a rapid cooling molding step, injecting a cryogenic fluid into the mold water path in the Fresnel lens injection molding device to rapidly cool the liquid thermoplastic material in the cavity And it is cooled and solidified into a Fresnel lens.

According to the above technical means, the Fresnel lens injection molding device and the related manufacturing method of the present invention use the first mold water path and the second mold water path for injecting hot steam, hot water or cold water, thereby quickly and uniformly Heating or cooling the mother mold and the male mold, so that the temperature of each part of the plastic material in the cavity is raised and lowered rapidly, uniformly and uniformly, and the surface of the Fresnel lens is prevented from being generated by the excessively long injection molding process. In addition, the uniform temperature control can prevent the thermoplastic material from being cooled and solidified first to cause short-shot phenomenon, thereby improving the sharpness of the sharp portion of the Fresnel lens, thereby improving the optical quality of the Fresnel lens.

The mold water path refers to the first mold water path in a master mold in the Fresnel lens injection molding apparatus.

The mold water path refers to the second mold water path in a male mold in the Fresnel lens injection molding apparatus.

The mold water path refers to a first mold water path in a master mold in the Fresnel lens injection molding apparatus and a second mold water path in a male mold.

In the rapid heating step, a hot water vapor is supplied to the mold water path through a quenching and hot mold temperature controller to perform rapid heat.

In the rapid cooling molding step, a quenching and hot mold temperature controller is used to input cold water to the mold water passage for quenching.

In the above-mentioned injection step, plastic is injected into the Fresnel lens injection molding apparatus through a plastic injection molding machine.

Another object of the present invention is to provide a Fresnel lens injection molding apparatus suitable for the above manufacturing method, comprising: a mother mold having at least one first assembly groove formed therein, and a first one formed in the mother mold a mold water passage, a first mold cavity communicating with the first assembly groove is formed on one side of the mother mold; a male mold connected to the female mold and movable relative to the female mold to abut or move away from the mother mold Forming, on the male mold, at least one second assembly groove that is matched with the corresponding first assembly groove, and forming, on one side of the male mold, a second cavity communicating with the second assembly groove, the second The cavity and the first cavity together form a cavity; at least one female die is respectively disposed in the corresponding first assembly groove; and at least one male die is respectively disposed in the corresponding second assembly groove, And match the mother mold kernel.

A second mold water path is formed in the male mold.

The first mold water path and the second mold water path are in a crisscross shape.

The mother mold has a mother mold pad and a female mold outer frame, and the at least one first assembly groove, the first mold water path and the first mold cavity are formed in the mother mold pad, and the female mold outer frame is Hollow and sleeved on the master mold pad.

The male mold has a male mold pad and a male mold outer frame, and the at least one second assembly groove, the second mold water path and the second cavity are formed in the male mold pad, and the male mold outer frame is Hollow and sleeved on the male mold pad.

The first assembly slot is plural, and the female mold core is plural; the first mold cavity has a first main plastic flow channel and a plurality of first branch plastic flow channels, and the plurality of first branch plastic flow channels are from the first The main plastic flow path extends outwardly and communicates with the plurality of first assembly grooves, respectively.

The second assembly tank is plural, and the male mold core is plural; the second mold cavity has a second main plastic flow passage and a plurality of second branch plastic flow passages, and the second main plastic flow passage corresponds to the first main The plurality of second branch plastic flow passages respectively correspond to the plurality of first branch plastic flow passages, and extend outward from the second main plastic flow passages and communicate with the plurality of second assembly grooves, respectively.

The two opposite apexes of the first mold water path are two first bus points, and each of the first bus points forms a first main branch path, and the first main branch path extends beyond the mother pad.

Two first sub-branch passages are formed on each of the first confluence points of the first mold water passage, and the two first sub-branch passages extend beyond the master mold pad.

The two opposite apexes of the second mold water path are two second bus points, and each of the second bus points forms a second main branch path, and the second main branch path extends beyond the male die pad.

Two second sub-branch passages are formed on each of the second confluence points of the second mold water passage, and the two second sub-branch passages extend beyond the male mold pad.

A first Fresnel structure transfer surface is formed on an inner side surface of the female mold core, and a second Fresnel structure transfer surface is formed on an inner side surface of the male mold core.

A first mold water channel is formed inside the mother mold.

A second mold water channel is formed inside the male mold core.

The two opposite vertices of the first mold water channel of the mother mold are two first communication points, and a first sealing hole is formed through a first sealing gasket disposed on the female mold core, and the two The first letting through hole and the two first connecting points are respectively connected.

The two opposite vertices of the second mold water channel of the male mold core are two second connecting points, and a second sealing hole is formed through a second sealing gasket disposed on the male mold core, the two The second yielding through holes are respectively connected to the two second connecting points.

The Fresnel lens injection molding apparatus further includes a fixed substrate and a movable substrate, wherein the fixed substrate and the mother mold are fixed to each other, and at least one first mold tube group is disposed on the fixed substrate, and each of the first mold cores The pipeline group has a first inflow pipe and a first outflow pipe to be respectively connected to the two first retaining holes of the corresponding female die; the movable substrate and the male die are fixed to each other, and at least one of the movable substrate is disposed on the movable substrate The second mold tube set, each of the second mold line sets has a second inflow tube and a second outflow tube to be respectively connected to the two second yielding through holes of the corresponding male mold.

It is still another object of the present invention to provide a Fresnel lens manufactured by the above manufacturing method, comprising: a lens body and a plurality of concentric annular ribs formed on the lens body and in a concentric manner Arranging, in a side section passing through a central axis of the Fresnel lens, the plurality of concentric annular ribs respectively have a sawtooth cross section, and the plurality of sawtooth sections are bilaterally symmetrical with respect to the central axis; at a magnification of up to 150 Under the observation of the microscope, the tips of the sawtooth sections of the concentric annular ribs are sharp and not rounded.

There is a sawtooth groove cross section between any two adjacent sawtooth sections, and the bottom of the zigzag groove section is sharp without rounded corners under the observation of a microscope up to 150 magnifications.

Referring to FIGS. 1 to 3 and FIG. 16, the Fresnel lens injection molding apparatus 1 of the present invention can be connected to a quenching hot mold temperature control machine 2 and a plastic injection molding machine 3, and includes: a mother mold 10, a male The mold 20, at least one female mold core 30, at least one male mold core 40, a fixed substrate 50, and a movable substrate 60.

Referring to FIGS. 4 and 9, at least one first assembly groove 130 is formed on the mother mold 10, and a first mold water path 135 is formed in the mother mold 10 for the quenching hot mold temperature control machine 2 The injected hot steam, hot water or cold water is injected thereinto to heat or cool the master mold 10 quickly and uniformly. The first mold water path 135 may be quadrilateral, spiral, U-shaped or any shape that may be uniformly distributed within the master mold 10. The high-temperature hot steam may be a high temperature of 140 degrees Celsius to 160 degrees Celsius, at which the good fluidity of the general thermoplastic plastic material can be maintained, and the hot steam temperature can be increased depending on the condition; in addition, the cold water can be 80 degrees Celsius to 90 degrees Celsius. At this temperature, the general thermoplastic plastic material can be cooled and solidified, and the temperature of the cold water can be increased or decreased depending on the situation. A first cavity communicating with the first assembly groove 130 is formed on one side of the mother mold 10 for the plastic injection molding machine 3 to inject a thermoplastic material therein. In addition, the temperature (also referred to as the material temperature) of the thermoplastic plastic material of the plastic injection molding machine 3 at the time of injection is usually between 200 and 260 degrees Celsius.

In a preferred embodiment, the master mold 10 has a mother mold pad 13 and a female mold outer frame 11, at least a first assembly groove 130, the first mold water path 135, and the first mold cavity formed therein. In the master mold block 13, the female mold outer frame 11 is hollow and sleeved on the master mold pad 13. The two opposite apexes of the first mold water path 135 are two first bus points 1350. Each of the first bus points 1350 forms a first main branch path 1351. The first main branch path 1351 extends to the master pad 13 outer. In addition, two first sub-bracket passages 1352 are formed on each of the first confluence points 1350, and the two first sub-branch passages 1352 extend beyond the master mold pad 13. The first main branch passage 1351 can connect a line from the quenching hot mold temperature control machine 2 for injecting hot steam, hot water or cold water into the master mold block 13. The first auxiliary branch passages 1352 can be locked with screws to seal the external lines, and can be connected to the quenching and hot mold temperature control machine 2 in other situations.

Referring to Figures 6 and 10 and 13, the male mold 20 and the female mold 10 are connected to each other and movable relative to the female mold 10 to abut or move away from the mother mold 10. A second mold water path 235 is formed in the male mold 20 for injecting hot steam, hot water or cold water injected into the quenching hot mold temperature control machine 2, thereby heating or cooling the male mold 20 quickly and uniformly. . The second mold water path 235 may be quadrilateral, spiral, U-shaped or any shape that may be evenly distributed within the male mold 20. The second mold water path 235 may be in a crisscross shape with the first mold water path 135 as shown in FIG. At least one second assembly groove 230 is formed on the male mold 20 to be matched with the corresponding first assembly groove 130. A second cavity communicating with the second assembly groove 230 is formed on one side of the male mold 20. The plastic injection molding machine 3 is used to inject a thermoplastic plastic material therein. The second cavity forms a cavity with the first cavity.

In a preferred embodiment, the male mold 20 has a male mold pad 23 and a male outer frame 21, and at least a second assembly groove 230, the second mold water path 235, and the second cavity are formed therein. In the male mold pad 23, the male mold outer frame 21 is hollow and sleeved on the male mold pad 23. The two opposite apexes of the second mold water path 235 are two second sink points 2350, and each of the second bus points 2350 forms a second main branch passage 2351 extending to the male mold pad 23 outer. In addition, two second sub-bracket passages 2352 are formed on each of the second confluence points 2350 of the second mold water passage 235, and the two second sub-branch passages 2352 extend beyond the male mold pad 23. The second main branch passage 2351 can connect a line from the quenching hot mold temperature control machine 2 for injecting hot steam, hot water or cold water into the male mold pad 23. The second auxiliary branch passages 2352 can be sealed by screws and can be connected to the quenching and hot mold temperature control machine 2 in other situations.

Referring to Figures 4 and 5 and 11, the female mold core 30 is disposed in the corresponding first assembly tank 130. A first mold water channel 35 is formed inside the female mold core 30 for injecting hot steam, hot water or cold water injected into the quenching hot mold temperature control machine 2, thereby heating or cooling the mother quickly and uniformly. Mould 30. The first mold water channel 35 can be quadrangular, spiral, U-shaped or any shape that can be evenly distributed within the female mold core 30. The two opposite apexes of the first mold water channel 35 are two first communication points 350. Two first through holes 31, 32 are formed through a first sealing gasket 301 disposed on the female mold core 30. The two first access holes 31, 32 are respectively connected to the two first communication points 350. In addition, a first Fresnel structure transfer surface 300 is formed on an inner side surface of the female mold core 30, which may be an aspherical surface. Further, the female mold core 30 may be provided with two bolts to further fix the first gasket 301 to the female mold core 30.

Referring to Figures 6, 7 and 12, the male mold core 40 is disposed in the corresponding second assembly groove 230 and matches the female mold core 30. A second mold water channel 45 is formed inside the male mold core 40 for injecting hot steam, hot water or cold water injected into the quenching hot mold temperature control machine 2, thereby rapidly or uniformly heating or cooling the male mold. Molding 40. The second mold water channel 45 can be quadrangular, spiral, U-shaped or any shape that can be evenly distributed within the male mold core 40. The two opposite apexes of the second mold water channel 45 of the male mold core 40 are two second communication points 450, and a second sealing pass is formed on a second sealing gasket 401 disposed on the male mold core 40. The holes 41, 42 are connected to the two second communication points 450, respectively. Further, a second Fresnel structure transfer surface 400 is formed on an inner side surface of the male mold core 40. A Fresnel lens can be manufactured by embossing the first Fresnel structure transfer surface 300 and the second Fresnel structure transfer surface 400 on the surface of the thermoplastic material in the cavity. Further, the male mold core 40 may be provided with two bolts to further fix the second sealing gasket 401 to the male mold core 40.

Referring to Figures 4, 6 and 8, in a preferred embodiment of the present invention, the first assembly slot 130 is plural, and the female die 30 is plural; the first cavity has a first main plastic flow path 136. And a plurality of first branch plastic runners 137 extending outward from the first main plastic runner 136 and in communication with the plurality of first assembly slots 130, respectively. In addition, the second assembly tank 230 is plural, and the male mold core 40 is plural; the second mold cavity has a second main plastic flow passage 236 and a plurality of second branch plastic flow passages 237, and the second main plastic flow passage 236 corresponding to the first main plastic flow channel 136, the plurality of second branch plastic flow channels 237 respectively corresponding to the plurality of first branch plastic flow channels 137, and extending outward from the second main plastic flow channel 236 and respectively associated with the plurality The second assembly tanks 230 are in communication with each other. Through the arrangement of the plurality of female mold cores 30 and the male mold core 40, the Fresnel lens injection molding apparatus 1 can produce a plurality of Fresnel lenses in a single processing procedure. The plastic distribution in the cavity is as shown in Fig. 8, and the main plastic flow path portion C36, the branch plastic flow path portion C37 connected to the main plastic flow path portion C36, and the plurality of branch plastic flow path portions C37 are respectively disposed. Fresnel lens plastic part 80a. The mother mold 10 and the male mold 20 are uniformly quenched and heated by injecting hot water vapor, hot water or cold water through the first mold water path 135 and the second mold water path 235, so that the main plastic flow path portion C36 and the branch plastic flow can be formed. The temperature of the road portion C37 and the Fresnel lens plastic portion 80a is uniformly raised and lowered, and there is no problem that the temperature of the local plastic material is too low and the first curing causes the Fresnel lens to be poorly formed and the optical quality is lowered.

The fixed substrate 50 and the mother mold 10 are fixed to each other. At least one first mold tube set is disposed on the fixed substrate 50. Each of the first mold tube sets has a first inflow tube 51 and a first outflow tube 52. The two first letting through holes 31, 32 are respectively connected to the corresponding female mold cores 30. The first inflow pipe 51 and the first outflow pipe 52 may be connected to the quenching hot mold temperature control machine 2, thereby injecting hot steam, hot water or cold water into the master mold 30.

The movable substrate 60 and the male mold 20 are fixed to each other. At least one second mold tube set is disposed on the movable substrate 60. Each of the second mold tube sets has a second inflow tube 61 and a second outflow. The tubes 62 are connected to the two second let-through holes 41, 42 of the corresponding male mold core 40, respectively. The second inflow pipe 61 and the second outflow pipe 62 may be connected to the quenching hot mold temperature control machine 2, thereby injecting hot steam, hot water or cold water into the male mold core 40.

Referring to Figures 1, 16 and 17, the method for manufacturing the Fresnel lens of the Fresnel lens injection molding apparatus 1 of the present invention comprises: a rapid heating step S01, an ejection step S02, and a transfer step S03. And a rapid cooling molding step S04.

The rapid heating step S01 includes injecting a high-heat fluid into at least one of the mold water paths in the Fresnel lens injection molding apparatus 1 for rapid heating to a temperature at which the thermoplastic plastic material can flow. The at least one mold water path may be separately the first mold water path 135 in the mother mold 10, or the second mold water path 235 in the male mold 20 alone, or the first mold water path 135 and the second mold water path 235. By. In the rapid heating step S01, the hot water vapor is supplied to the mold water passage through the quenching and hot mold temperature controller 2 to perform rapid heat.

The injection step S02 includes injecting a liquid thermoplastic material into a cavity in the Fresnel lens injection molding apparatus 1. In the injection step S02, the thermoplastic resin is injected into the Fresnel lens injection molding apparatus 1 through the plastic injection molding machine 3.

The transferring step S03 includes pressurizing the liquid thermoplastic material in the cavity with at least one pair of dies to produce a Fresnel lens structure in the thermoplastic material.

The rapid cooling molding step S04 includes injecting a cryogenic fluid into the mold water path in the Fresnel lens injection molding apparatus 1 to rapidly cool the liquid thermoplastic material in the cavity and cool it to a Fresnel lens. In the rapid cooling molding step S04, the quenching hot mold temperature controller 2 is supplied with cold water to the mold water passage to perform rapid cooling.

Referring to Figures 14 and 15, the Fresnel lens 80 manufactured by the above manufacturing method further comprises: a lens body and a plurality of concentric annular ribs, the plurality of concentric annular ribs being formed on the lens body and Arranging in a concentric manner, on a side section of the central axis of the Fresnel lens, the plurality of concentric annular ribs respectively have a sawtooth bump section 81, and the plurality of sawtooth bump sections 81 are based on the central axis. The left and right symmetrical distributions have a sawtooth groove section 82 between any two adjacent sawtooth bump sections 81.

Under the observation of a microscope up to 150 magnifications, the tips 811 of the zigzag bump sections 81 of the concentric annular ribs are sharp and not rounded, and the bottom 821 of each of the sawtooth groove sections 82 is sharp and not Rounded corners.

The invention has the following advantages:

1. The Fresnel lens injection molding apparatus 1 and related manufacturing method of the present invention employs a first mold water path 135 and a second mold water path 235 for injecting hot steam, hot water or cold water therein for rapid and uniform heating. Or cooling the mother mold 10 and the male mold 20, so that the temperature of each part of the plastic material in the cavity is raised and lowered rapidly, uniformly and uniformly, and the surface of the Fresnel lens is prevented from being generated by the excessively long injection molding process, Gas pattern, in addition, uniform temperature control can avoid the short-acting phenomenon caused by the partial cooling and solidification of the thermoplastic plastic material, thereby improving the sharpness of the sharp portion of the Fresnel lens, thereby improving the optical quality of the Fresnel lens, such as Figure 15 shows.

2. The first mold water path 135 and the second mold water path 235 of the mother mold 10 and the male mold 20 are arranged in a crisscross manner to further improve the uniform temperature control performance of the mother mold 10 and the male mold 20, and improve the finished Fresnel lens. Quality.

1‧‧‧Fresnel lens injection molding device

2‧‧‧Quick and hot hot mold temperature control machine

3‧‧‧Plastic injection molding machine

10‧‧‧Female mold

11‧‧‧Female mold frame

13‧‧‧ mother mold pad

130‧‧‧First assembly slot

135‧‧‧First mold waterway

1350‧‧‧First Convergence Point

1351‧‧‧First main branch path

1352‧‧‧First sub-branch access

136‧‧‧First main plastic runner

137‧‧‧ first branch plastic runner

20‧‧‧Male mold

21‧‧‧ Male mold frame

23‧‧‧Mold inserts

230‧‧‧Second assembly slot

235‧‧‧Second mold waterway

2350‧‧‧Second convergence point

2351‧‧‧Second main branch path

2352‧‧‧Second sub-branch access

30‧‧‧Female model

300‧‧‧First Fresnel Structure Transfer Surface

301‧‧‧First gasket

31, 32‧‧‧First let-through hole

35‧‧‧The first model waterway

350‧‧‧ first connection point

40‧‧‧Male model

400‧‧‧Second Fresnel Structure Transfer Surface

401‧‧‧Second gasket

41, 42‧‧‧Second handicap through hole

45‧‧‧Second Moss Waterway

450‧‧‧Second connection point

50‧‧‧Fixed substrate

51‧‧‧First inflow pipe

52‧‧‧First outflow tube

60‧‧‧ movable substrate

61‧‧‧Second inflow pipe

62‧‧‧Second outflow tube

80‧‧‧Fresnel lens

80a‧‧ Fresnel Lens Plastics Department

81‧‧‧Sawtooth bump section

811‧‧‧ cutting edge

82‧‧‧Sawtooth groove section

821‧‧‧ bottom

C36‧‧‧Main Plastic Flow Department

C37‧‧‧ branch plastic runner

90‧‧‧Traditional Fresnel lens

91‧‧‧ tip

92‧‧‧ Groove

Figure 1 is a perspective view of the present invention. Figure 2 is a cross-sectional view of the present invention. Fig. 3 is a perspective exploded view of the mother mold, the female mold core, the male mold and the male mold. Fig. 4 is a perspective exploded view of the mother mold pad and the female mold core of the present invention. Fig. 5 is a perspective exploded view of the mother mold of the present invention. Figure 6 is a perspective exploded view of the male mold pad and the male mold. Figure 7 is a perspective exploded view of the male mold of the present invention. Figure 8 is a perspective view of the plasticity of the plastic in the cavity of the present invention. Figure 9 is a plan view showing the mother pad of the present invention. Figure 10 is a plan view showing the male mold pad of the present invention. Figure 11 is a plan view showing the mother mold of the present invention. Figure 12 is a schematic plan view of the male mold core and its internal mold water passage of the present invention. Figure 13 is a schematic perspective view of the mold water path and the mold core line group in the direction in which the mother mold and the male mold are overlapped in the present invention. Figure 14 is a cross-sectional view of the Fresnel lens of the present invention along a central axis. Fig. 15 is a schematic enlarged cross-sectional view showing the Fresnel lens of the present invention under an electron microscope at 150 times optical magnification. Figure 16 is a block diagram of the system of the Fresnel lens injection molding apparatus, the quenching and hot mold temperature control machine, and the plastic injection molding machine of the present invention. Figure 17 is a flow chart showing the steps of a method for manufacturing a Fresnel lens of the present invention. Figure 18 is a schematic enlarged cross-sectional view of a conventional Fresnel lens under an electron microscope at 15 times optical magnification.

Claims (26)

A method for manufacturing a Fresnel lens, comprising: a rapid heating step of injecting a high-heat fluid into at least one mold water path in a Fresnel lens injection molding apparatus for rapid heating to a temperature at which a thermoplastic plastic material can flow; a step of injecting a liquid thermoplastic plastic material into a cavity in the Fresnel lens injection molding apparatus; and a transfer step of pressurizing the liquid thermoplastic material in the cavity with at least one pair of molds to pressurize the thermoplastic The plastic material generates a Fresnel lens structure; and a rapid cooling molding step of injecting a cryogenic fluid into the mold water path in the Fresnel lens injection molding apparatus to rapidly cool and cool the liquid thermoplastic material in the cavity Solidified into a Fresnel lens. The method of manufacturing a Fresnel lens according to claim 1, wherein the mold water path refers to a first mold water path in a mother mold in the Fresnel lens injection molding apparatus. The method of manufacturing a Fresnel lens according to claim 1, wherein the mold water path refers to a second mold water path in a male mold in the Fresnel lens injection molding apparatus. The method of manufacturing a Fresnel lens according to claim 1, wherein the mold water path refers to a first mold water path in a female mold in the Fresnel lens injection molding apparatus, and a second mold in a male mold. waterway. The method of manufacturing a Fresnel lens according to any one of claims 1 to 4, wherein in the rapid heating step, the hot water vapor is input to the mold water path through a quenching and hot mold temperature control machine for rapid heat generation. . The method of manufacturing a Fresnel lens according to any one of claims 1 to 4, wherein in the rapid cooling molding step, cold water is supplied to the mold water passage through a quenching and hot mold temperature controller to perform rapid cooling. The method of manufacturing a Fresnel lens according to any one of claims 1 to 4, wherein in the ejecting step, plastic is injected into the Fresnel lens injection molding apparatus through a plastic injection molding machine. A Fresnel lens injection molding apparatus apparatus according to the manufacturing method of claim 1, comprising: a mother mold having at least one first assembly groove formed therein, and a first mold water path formed in the mother mold, Forming a first cavity communicating with the first assembly groove on one side of the master mold; a male mold interconnected with the female mold to be movable relative to the female mold to abut or move away from the mother mold, Forming, on the male mold, at least one second assembly groove that is matched with the corresponding first assembly groove, and forming, on one side of the male mold, a second cavity communicating with the second assembly groove, the second cavity being The first cavity together constitutes the cavity; at least one female die is respectively disposed in the corresponding first assembly groove; and at least one male die is respectively disposed in the corresponding second assembly groove, and Matches the master mold. A Fresnel lens injection molding apparatus according to claim 8, wherein a second mold water path is formed in the male mold. The Fresnel lens injection molding apparatus according to claim 9, wherein the first mold water path and the second mold water path are crisscrossed. The Fresnel lens injection molding apparatus according to claim 9, wherein the mother mold has a mother mold pad and a female mold outer frame, the at least one first assembly groove, the first mold water path, and the first mold A hole is formed in the master mold pad, and the outer frame of the master mold is hollow and sleeved on the master mold pad. The Fresnel lens injection molding apparatus according to claim 9, wherein the male mold has a male mold pad and a male mold outer frame, the at least one second assembly groove, the second mold water path, and the second mold A hole is formed in the male mold pad, and the male mold outer frame is hollow and sleeved on the male mold pad. The Fresnel lens injection molding apparatus according to claim 9, wherein the first assembly groove is plural, and the female mold core is plural; the first cavity has a first main plastic flow path and a plurality of first branches a plurality of first branch plastic flow passages extending outward from the first main plastic flow passage and communicating with the plurality of first assembly grooves, respectively. The Fresnel lens injection molding apparatus according to claim 13, wherein the second assembly groove is plural, and the male mold core is plural; the second mold cavity has a second main plastic flow path and a plurality of second branches a plastic flow channel, the second main plastic flow channel corresponding to the first main plastic flow channel, the plurality of second branch plastic flow channels respectively corresponding to the plurality of first branch plastic flow channels, and outward from the second main plastic flow channel Extending and communicating with the plurality of second assembly slots, respectively. The Fresnel lens injection molding apparatus according to claim 11, wherein two opposite vertices of the first mold water path are two first convergence points, and a first main branch path is formed on each first convergence point, the first main The branch path extends beyond the master pad. The Fresnel lens injection molding apparatus of claim 15, wherein each of the first confluence points of the first mold water path forms two first sub-branch passages, and the two first sub-branch passages extend to the master mold pad Outside. The Fresnel lens injection molding apparatus according to claim 12, wherein two opposite vertices of the second mold water path are two second convergence points, and a second main branch path is formed on each second convergence point, the second main The branch path extends beyond the male mold pad. The Fresnel lens injection molding apparatus according to claim 17, wherein two second sub-bracket passages are formed on the second confluence points of the second mold water passage, and the two second sub-branch passages extend to the male mold pad Outside. The Fresnel lens injection molding apparatus according to claim 8, wherein a first Fresnel structure transfer surface is formed on an inner side surface of the female mold core, and a second surface is formed on an inner side surface of the male mold core. Fresnel structure transfer surface. The Fresnel lens injection molding apparatus according to claim 8, wherein a first mold water passage is formed inside the female mold core. The Fresnel lens injection molding apparatus according to claim 20, wherein a second mold water passage is formed inside the male mold. The Fresnel lens injection molding apparatus according to claim 21, wherein two opposite vertices of the first mold water channel of the female mold core are two first communication points, and a first one is disposed on the female mold core Two first letting through holes are formed through the sealing gasket, and the two first letting through holes are respectively connected to the two first connecting points. The Fresnel lens injection molding apparatus according to claim 22, wherein two opposite vertices of the second mold water passage of the male mold are two second communication points, and a second seal is disposed on the male mold Two second retaining through holes are formed in the gasket, and the two second retaining through holes are respectively connected to the two second connecting points. The request item 23 to the Fresnel lens injection molding apparatus further includes a fixed substrate and a movable substrate, wherein the fixed substrate and the mother mold are fixed to each other, and at least one first mold tube is disposed on the fixed substrate. The first mold tube set has a first inflow tube and a first outflow tube for respectively connecting to the two first yielding through holes of the corresponding female mold core; the movable substrate and the male mold are fixed to each other, The movable substrate is provided with at least one second mold tube set, and each of the second mold tube sets has a second inflow tube and a second outflow tube for respectively connecting to the second male position of the corresponding male mold hole. A Fresnel lens manufactured by the manufacturing method of claim 1, comprising: a lens body and a plurality of concentric annular ribs formed on the lens body and arranged in a concentric manner, The plurality of concentric annular ribs have a sawtooth cross section on a side section passing through a central axis of the Fresnel lens, and the plurality of sawtooth sections are bilaterally symmetrical with respect to the central axis; at a microscope with a magnification of up to 150 Under observation, the tips of the sawtooth sections of the concentric annular ribs are sharp and not rounded. The Fresnel lens of claim 25, wherein any two adjacent sawtooth sections have a sawtooth groove cross section, and the bottom of the sawtooth groove cross section is observed under the microscope at a magnification of up to 150 magnifications. Sharp and not rounded.