Device and method for forming aspherical lens constrained by active surface shape of deformable die

Abstract

The invention belongs to the field of aspherical lens forming, and discloses an aspherical lens forming device and method for active surface shape constraint of a deformable die. A lens forming cavity is defined by the two flexible mold bodies and the supporting piece, or a lens forming cavity is defined by one flexible mold body, the initial base body and the supporting piece. The deformation driving device of the flexible mold body comprises a plurality of annular ejection pieces which are sequentially arranged from the center of the flexible mold body to the outer ring and cover the whole flexible mold, and each annular ejection piece is driven by at least two driving devices. And each driving device drives the annular ejector piece to do millimeter-scale macroscopic linear motion before the optical resin is cured, and drives the annular ejector piece to do micron-scale or nano-scale microcosmic motion in the curing process of the optical resin.

Description

Technical Field

[0001] The invention belongs to the field of aspheric lens forming, and relates to a method and a device for forming an aspheric lens with active surface shape constraint of a deformable mold. Background Art

[0002] As the number of people with vision problems in the market continues to increase, the demand for aspherical lenses is also expanding. At the same time, with the continuous development of science and technology, VR technology is constantly improving and its application scope is constantly expanding. Since spherical aberration, chromatic aberration, distortion and other problems are more common when wearing VR equipment, aspherical lenses are needed to optimize and avoid such problems.

[0003] At present, the forming method of aspheric lenses is basically the same as that of spherical lenses, including injection molding and compression molding. However, the method used more often in the production of aspheric lenses is injection molding. During the injection molding process, the shape of the mold is generally immutable. In order to form different lenses, different molds need to be replaced. Therefore, the production cost is high and the cycle is long. Some flexible molds for lens production have appeared in the prior art. For example, the patent AU2002319618A1 discloses a lens forming device and related methods, but the patent only provides that the mold can be deformed to adapt to different lenses, but how to control the deformation of the mold is not disclosed. The patent US20090146331A1 also discloses a manufacturing process for eyeglass lenses. At the same time, some deformable mold platforms are also disclosed in the prior art, but the deformation of the mold is directly driven by a number of ejector pins to deform the mold, and the cost of this driving method is relatively high. Because compared with free-form surface lenses, aspheric lenses are relatively simple, symmetrical structures, and only need to be optimized on one meridian. If the existing driving method is still used, the cost of the device will be relatively high. The materials used in the production of lenses are optical resins or light-curing adhesives, which are light-cured in combination with ultraviolet light sources. No heating is required and the curing is rapid, which minimizes the process and difficulty of operation. During the curing process, as the resin changes from liquid or semi-liquid to solid, the spacing between the molecular chains forming the cross-linked structure decreases, and its volume shrinks. In addition, due to factors such as curing shrinkage and thermal expansion, stress will be generated inside the resin during the curing process, and stress concentration will cause material deformation and affect the quality of the final product. Currently, most methods to solve problems such as material shrinkage during the curing process focus on changing the material formula or adjusting the light source required for its curing. However, this adjustment is not jointly controlled with the mold control. Therefore, when the lens precision requirements are relatively high, the lens precision requirements cannot be met. Summary of the invention

[0004] In order to shorten the optical mold manufacturing cycle, reduce the mold processing cost, and meet the diversified personalized customization production needs of lenses, the present invention proposes a deformable aspheric lens mold. Combining the symmetrical design characteristics of aspheric lenses and the characteristics of optimization on a meridian, the ring structure is used to drive the flexible mold cavity surface, and the high-precision displacement is combined to meet the contour offset compensation during the mold processing process to achieve a one-time rapid forming effect. At the same time, during the curing process of optical resin, due to the influence of factors such as curing speed and stress, the spacing between the molecular chains of the material changes, resulting in shrinkage, and even random errors such as tiny depressions on the lens surface, affecting the accuracy of the finished lens. The present invention controls the displacement of the deformable surface of the mold during the curing process, compensates for the shrinkage, and controls the final forming effect. It can effectively reduce the error generated by the lens during the curing process, realize personalized customization of aspheric lenses, improve production efficiency, and flexibly adapt to the production design needs of various aspheric lenses.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows: In the first aspect, the present invention provides a deformable aspheric lens mold, comprising a flexible mold body; two flexible mold bodies and a support member form a lens forming cavity, or a flexible mold body, an initial substrate and a support member form a lens forming cavity; the deformation driving device of the flexible mold body comprises a plurality of annular top pieces, and the plurality of annular top pieces are arranged in sequence from the center to the outer circle of the flexible mold body, covering the entire flexible mold, each annular top piece is driven by at least two driving devices, each driving device drives the annular top piece to perform millimeter-level macroscopic linear motion before the optical resin is cured, and drives the annular top piece to perform micrometer or nanometer-level microscopic motion during the optical resin curing process.

[0006] As a further technical solution, the driving device includes a first-stage driving device and a second-stage driving device. The first-stage driving device drives the annular top piece to perform millimeter-level macroscopic linear motion before the optical resin is cured, and the second-stage driving device drives the annular top piece to perform micrometer-level or nanometer-level microscopic motion during the optical resin curing process.

[0007] As a further technical solution, the corresponding driving devices of the same flexible mold body are staggered.

[0008] As a further technical solution, the contact surface between the annular top piece and the flexible mold is a non-spherical surface.

[0009] As a further technical solution, the support member is a transparent member, and a circle of light sources is arranged on its outer circle.

[0010] As a further technical solution, a heating film is arranged in the interlayer of the flexible mold body, and the heating film is arranged concentrically in a ring from the center to the outer circle of the flexible mold body.

[0011] In a second aspect, the present invention provides a forming method, which is as follows: Step 1: Obtain the three-dimensional structure of the lens to be formed, and obtain the three-dimensional structure of the specific surface shape of the flexible mold body after compensating the lens to be formed in combination with the lens forming material and relevant parameters in the curing process; Step 2: According to the three-dimensional structure of the surface of the flexible mold body obtained in step 1, the driving device is controlled to perform macroscopic and / or microscopic deformation adjustment on the flexible mold body; Step 3: injecting liquid light-curing resin or heat-curing resin into the lens forming cavity; Step 4 sets a light source on the outer circle of the lens forming cavity, or sets a heating film in the interlayer of the flexible mold body, so as to control the curing speed of the photocurable resin or the thermosetting resin, synchronously control the driving device to respond quickly, adjust the mold in the corresponding area to perform micro-deformation, so that the contraction of the photocurable resin or the thermosetting resin is always kept under the constraint of the mold.

[0012] As a further technical solution, in step 2, the control process for the macroscopic deformation of the flexible mold body is: driving the mold body from the area with small deformation to the area with large deformation gradually.

[0013] As a further technical solution, in step 4, the specific collaborative control method of the light source and the driving device is as follows: The light source is arranged in a circle, and during the curing process of the optical resin, light curing is performed step by step from the outer circle to the inner circle. During the curing process, the intensity of the light source gradually increases. At the same time, the driving device is driven step by step from the outer circle to the inner circle during the light curing process.

[0014] As a further technical solution, the specific control method of the heating film and the driving device is as follows: The thermosetting resin is thermoset from the thickest position, and the corresponding driving device is driven according to the thermosetting deformation.

[0015] The beneficial effects of the present invention are as follows: The present invention combines the symmetrical design characteristics of aspherical lenses and the characteristics of optimization on a meridian, uses an annular top piece to drive the specific cavity surface of the flexible mold, and combines high-precision displacement to meet the contour offset compensation during the mold processing process to achieve the effect of one-time rapid prototyping. And by utilizing the high-precision, controllable and deformable characteristics of the deformable mold, it works in conjunction with the light curing / thermal curing process, and the deformation of the flexible mold body is used to compensate for the resin shrinkage, while limiting the shrinkage direction and curing shape to avoid the randomness of the resin during free curing; the shrinkage change is constrained in the controllable surface deformation process, improving the product surface accuracy and yield rate.

[0016] The present invention drives the annular top piece to move through a driving component to achieve controllable deformation of the flexible mold and quickly respond to the aspheric optical lens design with different data. After liquid photocurable glue or optical resin is injected into the mold and formed through photocuring or thermal curing, high-quality optical lenses with stable properties can be obtained in batches. The high cost of manufacturing different molds for different optical lens designs is effectively avoided, and the product development cycle is greatly shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A flow chart of the aspheric lens forming method with active surface shape constraint of a deformable mold proposed by the present invention; Figure 2 Schematic diagram of the aspheric lens forming device with active surface shape constraint of the deformable mold proposed in the first embodiment of the present invention Figure 1 ; Figure 3 Schematic diagram of the aspheric lens forming device with active surface shape constraint of the deformable mold proposed in the first embodiment of the present invention Figure 2 ; Figure 4 Schematic diagram of the aspheric lens forming device with active surface shape constraint of the deformable mold proposed in the first embodiment of the present invention Figure 3 ; Figure 5 Schematic diagram of the aspheric lens forming device with active surface shape constraint of the deformable mold proposed in the first embodiment of the present invention Figure 4 ; Figure 6 A schematic diagram of an aspheric lens forming device with active surface shape constraint of a deformable mold proposed in the second embodiment of the present invention; Figure 7 A schematic diagram of an aspheric lens forming device with active surface shape constraint of a deformable mold proposed in the third embodiment of the present invention; In the figure: 1. Shell; 2. First two-stage driving device; 2-1. First stage driving device, 2-2. Second stage driving device, 3. First annular top piece; 4. First flexible mold body; 5. Injection port; 6. Optical resin; 7. Ultraviolet light source; 8. Support member; 9. Second flexible mold body; 10. Second two-stage driving device; 11. Second annular top piece; 13. Initial base; 14. Clamp; 15. Heating film. DETAILED DESCRIPTION

[0018] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0019] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless otherwise explicitly stated in the present invention, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof; In order to shorten the manufacturing cycle of optical molds, reduce mold processing costs, and meet the diversified personalized customization production needs of lenses, this embodiment proposes a non-spherical lens forming device with active surface shape constraints of a deformable mold. Combined with the symmetrical design characteristics of the non-spherical lens and the characteristics of optimization on a meridian, the ring structure is used to drive the flexible mold cavity surface, and the high-precision displacement is combined to meet the contour offset compensation during the mold processing process to achieve a one-time rapid forming effect. At the same time, during the curing process of the optical resin 6, due to the influence of factors such as curing speed and stress, the spacing between the molecular chains of the material changes, resulting in shrinkage, and even causing random errors such as tiny depressions on the lens surface, affecting the accuracy of the finished lens. The present invention controls the displacement of the deformable surface of the mold during the curing process, compensates for the shrinkage, and controls the final forming effect, which can effectively reduce the error generated by the lens during the curing process, realize personalized customization of non-spherical lenses, improve production efficiency, and flexibly adapt to the production design needs of various non-spherical lenses.

[0020] Embodiment 1 This embodiment provides a non-spherical lens forming device with active surface shape constraint of a deformable mold, the structure of which is as follows Figure 2 , Figure 3 , Figure 4 As shown, it mainly consists of a housing 1, a first flexible mold body 4, a first annular top piece 3, a first two-stage driving device 2, a second flexible mold body 9, a second annular top piece 11, a second two-stage driving device 10, and a support member 8; The first flexible mold body 4 and the second flexible mold body 9 are arranged up and down, and together with the support member 8, form a lens forming cavity; a resin injection port 5 is provided on the support member 8, and the hole is sealed after the resin is injected; The deformation driving device of the first flexible mold body 4 includes a plurality of first annular top pieces 3, which are arranged in sequence from the center to the outer circle of the first flexible mold body 4 to cover the entire first flexible mold, and each first annular top piece 3 is driven by at least two first driving devices, and the first driving devices drive the annular top piece to perform millimeter-level macroscopic linear motion before the optical resin 6 is cured, and drive the annular top piece to perform microscopic motion at the micrometer or nanometer level during the curing process of the optical resin 6; The deformation driving device of the second flexible mold body 9 includes a plurality of second annular top pieces 11, which are arranged in sequence from the center to the outer circle of the second flexible mold body 9 to cover the entire second flexible mold. Each second annular top piece 11 is driven by at least two second driving devices. The second driving device drives the annular top piece to perform millimeter-level macroscopic linear motion before the optical resin 6 is cured, and drives the annular top piece to perform micron or nanometer-level microscopic motion during the curing process of the optical resin 6.

[0021] Furthermore, the materials of the first flexible mold body 4 and the second flexible mold body 9 can be high elastic alloys or shape memory alloys. After each batch of components is produced, when the mold body needs to be deformed, it can be restored to its original shape by elastic recovery and temperature change, and the deformation can be adjusted again according to the new lens shape. In addition to relying on its own elastic deformation or thermal recovery, the specific recovery of the flexible mold can be circumferentially applied with negative pressure or installed with springs to assist the flexible mold body in restoring its original shape.

[0022] Furthermore, the materials of the first flexible mold body 4 and the second flexible mold body 9 can also be shape memory polymers (such as styrene and vinyl compounds, on which a cross-linking agent, an initiator and a modified polymer are added), which have greater fatigue strength and better deformation recovery than shape memory alloys. After the flexible mold body recovers its initial shape, the above process can be repeated to produce optical lenses with different surface shapes.

[0023] Furthermore, each annular top piece is used to apply a deformation force to the flexible mold body. Since the aspherical lens is symmetrically designed, an annular top piece is used instead of a top rod. At the same time, the aspherical lens is optimized on a meridian relative to the spherical lens, so the annular structure is nested and distributed in a progressive manner, and the different top-up heights between each layer are used to achieve optimization on a meridian. The upper end of the annular top piece adopts an aspherical surface to avoid local protrusions and poor bonding as much as possible.

[0024] Furthermore, the drive device uses a staggered arrangement of micro electric cylinders or linear actuators as a power source, and each micro electric cylinder or linear actuator corresponding to the annular top piece is connected in series. The end of the drive device is directly connected to the annular top piece, and the electric cylinder or actuator connected to the annular top piece synchronously and directly drives the axial displacement of the top piece. Of course, the annular top piece can also be connected by using a lead screw, using a voice coil motor as a driving power source, and using the angle characteristics of the lead screw nut to achieve self-locking. The drive components corresponding to each annular top piece of different diameters are arranged in a staggered manner.

[0025] Furthermore, each of the driving devices can also be designed as a two-stage drive, that is, a macro-micro drive structure design, and its accuracy is ensured to meet the application requirements through two-stage drive. Specifically, by setting piezoelectric ceramics at the end of the top rod of the micro electric cylinder or linear actuator, the micro electric cylinder or linear actuator is used as the first-stage driving device, that is, a macro driving device; piezoelectric ceramics are used as the second-stage driving device, that is, a micro driving device, to ensure the surface accuracy and fine-tuning during the resin curing process, and to ensure the surface quality of the final product. Specifically in this embodiment, the first driving device in this embodiment is a first two-stage driving device 2, the first two-stage driving device 2 includes a first-stage driving device 2-1 and a second-stage driving device 2-2, the first-stage driving device 2-1 is a micro electric cylinder or linear actuator, and the second-stage driving device 2-2 is a piezoelectric ceramic; correspondingly, the second driving device is a second two-stage driving device 10, and the second two-stage driving device 10 also includes a first-stage driving device and a second-stage driving device, the first-stage driving device is a micro electric cylinder or linear actuator, and the second-stage driving device is a piezoelectric ceramic.

[0026] Furthermore, the micro-electric cylinder or linear actuator, as the first-stage driving device, generates a macroscopic driving of millimeter-level displacement when driving the deformation of the flexible mold body, and the mechanical error of the driving device can be ignored at this time. The piezoelectric ceramic, as the second-stage driving device, fine-tunes the surface shape after the first driving device finishes working, and compensates for its shrinkage and controls the surface shape during the curing process of the optical resin 6, and can generate microscopic movement of micrometer-level or even nanometer-level displacement.

[0027] Furthermore, in order to avoid errors, the push rod of the micro-electric cylinder or linear drive in this embodiment is connected to the housing 1 through a linear bearing to avoid obvious radial deviation during movement. Figure 4 This is a top view of the present invention after removing the upper shell 1. Each ring can be driven by 2-3 drivers, and the rings are matched with ultra-precision clearances to ensure that there is no position deviation during the movement, thereby ensuring the final position accuracy. In addition, the surface accuracy after deformation can be ensured by adding a gasket or using a suitable material thickness on the contact surface between the deformable mold body and the annular top piece to avoid obvious annular protrusions.

[0028] Furthermore, the above-mentioned support member is made of transparent material, and a circle of ultraviolet light sources 7 is arranged on the outer circle of the support member; Furthermore, due to the different curing speeds and the uneven distribution of internal stress during the curing process, the volume of the optical resin 6 will shrink after curing is completed, and the deformable mold can compensate for it to a certain extent by using its high precision and deformability. For example, the shrinkage of the optical resin 6 can be calculated in advance, and a margin can be left in the initial deformation stage. At the beginning of curing, according to the different curing stages, pressure is gradually applied to the deformable surface of the mold from the outside to the inside to deform the flexible mold body, so as to adjust the shrinkage rate and shape of the resin, and finally cure to achieve the pre-designed optimal contour. At the same time, applying pressure to the cured area helps to balance the stress generated in the area being cured during the curing process.

[0029] The idea of ​​calculating its shrinkage is as follows: total shrinkage = shrinkage caused by density change + shrinkage caused by temperature change + shrinkage caused by stress change, that is, .

[0030] The shrinkage caused by the density change is as follows (can also be expressed in volume):

[0031] Temperature has a significant effect on the shrinkage during the curing process of the resin, especially in the light curing process. Temperature not only affects the curing rate and crosslinking density of the resin, but also affects the volume expansion or contraction of the resin. Specifically, the volume change of the resin due to temperature change can be estimated by introducing the thermal expansion coefficient:

[0032] During the resin curing process, stress may be generated inside the resin due to temperature changes, uneven light, uneven material shrinkage, etc. These stresses will affect the volume and shape of the resin. The volume change caused by stress can usually be calculated through the stress-strain relationship.

[0033]

[0034] Where E is the elastic modulus of the resin material used, is Poisson's ratio, To calculate the stress during the curing process, the stress distribution during the curing process can be simulated.

[0035] Based on the above description of the deformable mold and the description of the shrinkage during the curing process, the forming process of the aspheric lens can be optimized. The required surface shape is obtained by combining the data of the required lens production. Here, the aspheric surface shape is usually described by the following formula:

[0036] Where z is the surface sag, c is the vertex curvature of the aspherical surface, and k is the coefficient of the quadratic curve. k>0 is an oblate ellipse, k=0 is a sphere, k=-1 is a parabola, k<-1 is a hyperbola, and 0>k>-1 is a long ellipse. In addition, this formula is a two-dimensional description of the mirror shape base, which is converted to a three-dimensional coordinate system:

[0037] After obtaining the desired surface shape, the shrinkage amount of different positions of the lens can be obtained according to the geometric parameters such as thickness and curvature of different areas of the lens in the optical design, the curing parameters such as light intensity, and the curing characteristic parameters of the optical resin 6, and then the mold surface shape with material shrinkage margin can be obtained.

[0038] Furthermore, in this embodiment, the resin can be cured by a UV light source. During the curing process, the mold annular top piece is driven to deform the deformable surface to compensate for the shrinkage error and constrain the surface shape after curing, so that the curing process of the optical resin 6 is always carried out under the constraint of the mold surface, and finally the desired shape is formed, and the surface accuracy of less than 0.5 microns is obtained. (The process is as follows Figure 1 as shown).

[0039] This embodiment drives the annular top piece to move through the driving assembly to achieve specific controllable deformation of the flexible mold, quickly respond to the design of aspheric optical lenses with different data, and after the liquid photocurable glue or optical resin 6 is injected into the mold and formed by photocuring or thermal curing, high-quality optical lenses with stable properties can be obtained in batches. It effectively avoids the high cost of manufacturing different molds for different optical lens designs and greatly shortens the product development cycle. At the same time, the deformable surface of the mold cavity is utilized to drive the surface to deform during the curing process, and the surface shape is controlled to produce synergistic effects during the free curing process, so that the shrinkage changes are constrained in the controllable surface deformation process, thereby improving the surface accuracy and yield rate of the product.

[0040] The specific forming process of the above device is as follows: Step 1: After the optical lens is designed and finalized, a three-dimensional model of the optical lens can be obtained, and the models of the first flexible mold body 4 and the second flexible mold body 9 can be obtained according to parameters such as the shrinkage rate of the light-curing glue or optical resin 6 used during the curing process; Step 2: Discretize the geometric parameters of the first flexible mold body 4 and the second flexible mold body 9 into the axial movement distance corresponding to each annular top piece, and gradually adjust the position of each annular top piece until it is the same as the mold model to obtain a lens forming cavity; Step 3: injecting liquid light-curable resin into the lens forming cavity; In step 4, an ultraviolet light source 7 is arranged at the outer ring of the lens forming cavity to control the curing speed of the photocurable resin, synchronously control the driving device to respond quickly, and adjust the mold in the corresponding area to perform micro-deformation, so that the shrinkage of the photocurable resin or the thermosetting resin is always kept under the constraint of the mold.

[0041] In step 2, the control process for the macroscopic deformation of the flexible mold body is: driving the mold body from the area with small deformation to the area with large deformation gradually; in this embodiment, a concave-convex mirror is formed; Figure 1 During the macro-forming process, the upper die is driven step by step from the outer ring to the inner ring; the lower die is driven step by step from the outer ring to the inner ring.

[0042] As a further technical solution, in the step 4, the specific coordinated control method of the ultraviolet light source 7 and the driving device is as follows: the ultraviolet light source 7 is arranged in a circle, and the optical resin 6 is light-cured step by step from the outer circle to the inner circle during the curing process. The intensity of the ultraviolet light source 7 gradually increases during the curing process. At the same time, the driving device is driven step by step from the outer circle to the inner circle during the light-curing process.

[0043] After completing the production of this batch, the top piece is controlled to return to the initial position. During this process, the flexible mold body recovers its original shape through elastic recovery (high elastic alloy, amorphous alloy) or temperature change (shape memory alloy). The above process can be repeated to produce optical lenses with different surface shapes.

[0044] Embodiment 2 Compared with designing both the front and back surfaces of the lens, for some production needs with relatively small personalized requirements or relatively low requirements on the face shape, the design difficulty can be reduced and the mass production efficiency can be improved by designing one of the surfaces as a flat surface or using a pre-designed fixed face shape mold.

[0045] like Figure 6 As shown, the lens with the upper surface prefabricated is used as the initial substrate 13. The upper surface has been formed and coated, and the lower surface needs to be formed according to the customer's customized requirements. The initial substrate 13 is fixed on the top of the deformable mold body using a fixture 14, and the optical resin 6 is injected into the closed cavity formed by the two. The optical lens forming method with active surface shape constraint of the deformable mold is adopted. While curing, the mold deformation of the corresponding area is adjusted according to the curing speed of the optical resin 6, so that the shrinkage of the optical resin 6 is always kept under the constraint of the mold, thereby forming a stable and controllable curing shrinkage deformation, and finally becoming the designed surface shape of the optical lens. After the optical resin 6 is completely cured and demolded, it becomes a complete customized lens.

[0046] For this working condition, the selection of ultraviolet light source 7 and curing parameters can be adjusted according to actual needs. For example, a planar ultraviolet light source 7 can be used for overall irradiation to increase the curing speed of the optical resin 6; or a planar ultraviolet light source 7 can be used in combination with an aperture to achieve variable-aperture light curing, reduce the stress and deformation caused by the curing of the optical resin 6, and improve the lens forming accuracy.

[0047] Embodiment 3 The device in Example 1 or Example 2 is not only capable of performing photocuring forming, but is also suitable for thermal curing forming. The difference from Example 1 or Example 2 is that the ultraviolet light source 7 is no longer provided in the device, but a heat source is provided instead, and the lens forming cavity is filled with a thermal curing resin. During the thermal curing process, the annular top piece of the mold is driven to deform the deformable surface to compensate for the shrinkage error and constrain the surface shape after curing, so that the curing process of the optical resin 6 is always carried out under the constraint of the mold surface, and finally the desired shape is formed to obtain a surface accuracy of less than 0.5 microns.

[0048] Specifically, Figure 7 As shown, a heating film 15 is placed inside the specific material of the flexible mold in Example 1 or Example 2, so that the lens can be finally formed through thermal curing. Since temperature is an important factor affecting the curing rate and curing effect during thermal curing, the curing speed of the resin can be controlled by adjusting the heating power of the heating film 15. At that time, the shrinkage amount and shrinkage rate of the thermally cured optical resin 6 are obtained according to relevant conditions such as temperature, and then its shrinkage is compensated, and its shrinkage direction and final surface shape are controlled, so that the final surface shape and ideal accuracy desired by the present application can be obtained. For example, an annular heating film is used to correspond to the annular top piece, and heating is started from the place where more resin is injected, such as in Figure 7 The outer heating film can be heated first to ensure that the outer layer with more resin is cured first, and then the inner heating film 15 can be heated to ensure the synchronous curing of the internal resin to reduce the internal stress caused by uneven curing. At the same time, when the outer heating film 15 starts to be heated first, the outer ring top piece is driven to compensate for the shrinkage deformation first, and then as the interior gradually starts to heat, the inner ring is also driven to compensate for the shrinkage deformation.

Claims

1. A non-spherical lens forming device with active surface shape constraint of a deformable mold, characterized in that: It comprises a flexible mold body; wherein two flexible mold bodies and a support member form a lens forming cavity, or a flexible mold body, an initial base body and a support member form a lens forming cavity; the deformation driving device of the flexible mold body comprises a plurality of annular top pieces, which are arranged in sequence from the center to the outer circle of the flexible mold body, covering the entire flexible mold, each annular top piece is driven by at least two driving devices, each driving device drives the annular top piece to perform macroscopic linear motion before the optical resin is cured, and drives the annular top piece to perform microscopic motion during the curing process of the optical resin.

2. The aspheric lens forming device with active surface shape constraint of a deformable mold as claimed in claim 1, characterized in that: The driving device comprises a first-stage driving device and a second-stage driving device. The first-stage driving device drives the annular top piece to perform millimeter-level macroscopic linear motion before the optical resin is cured, and the second-stage driving device drives the annular top piece to perform micrometer-level or nanometer-level microscopic motion during the optical resin curing process.

3. The aspheric lens forming device with active surface shape constraint of a deformable mold as claimed in claim 1, characterized in that: The corresponding driving devices of the same flexible mold body are arranged in a staggered manner.

4. The aspheric lens forming device with active surface shape constraint of a deformable mold as claimed in claim 1, characterized in that: The contact surface between the annular top piece and the flexible mold is a non-spherical surface.

5. The aspheric lens forming device with active surface shape constraint of a deformable mold as claimed in claim 1, characterized in that: The supporting member is a transparent member, and a circle of light sources is arranged on its outer circle.

6. The aspheric lens forming device with active surface shape constraint of a deformable mold as claimed in claim 1, characterized in that: A heating film is arranged in the interlayer of the flexible mold body, and the heating film is arranged concentrically in a ring shape from the center to the outer circle of the flexible mold body.

7. The forming method of the aspheric lens forming device with active surface shape constraint of a deformable mold according to any one of claims 1 to 6, characterized in that: The details are as follows: Step 1: obtaining the three-dimensional structure of the lens to be formed, combining the lens forming material and relevant parameters in the curing process, and obtaining the three-dimensional structure of the specific surface shape of the flexible mold body after compensating the lens to be formed; Step 2: According to the three-dimensional structure of the surface of the flexible mold body obtained in step 1, the driving device is controlled to perform macroscopic and / or microscopic deformation adjustment on the flexible mold body; Step 3: injecting liquid light-curing resin or heat-curing resin into the lens forming cavity; Step 4 sets a light source on the outer circle of the lens forming cavity, or sets a heating film in the interlayer of the flexible mold body, so as to control the curing speed of the photocurable resin or the thermosetting resin, synchronously control the driving device to respond quickly, adjust the mold in the corresponding area to perform micro-deformation, so that the contraction of the photocurable resin or the thermosetting resin is always kept under the constraint of the mold.

8. The forming method according to claim 7, characterized in that: In the step 2, the control process for the macroscopic deformation of the flexible mold body is: driving the mold body from the area with small deformation to the area with large deformation gradually.

9. The forming method according to claim 7, characterized in that: In step 4, the specific collaborative control method of the light source and the driving device is as follows: The light source is arranged in a circle, and during the curing process of the optical resin, light curing is performed step by step from the outer circle to the inner circle. During the curing process, the intensity of the light source gradually increases. At the same time, the driving device is driven step by step from the outer circle to the inner circle during the light curing process.

10. The forming method according to claim 7, characterized in that: The specific control method of the heating film and the driving device is as follows: thermal curing is started from the thickest position of the thermal curing resin, and the corresponding driving device is driven according to the thermal curing deformation.

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