Lens device, electronic device, method of manufacturing the lens device, and mask

Abstract

Embodiments of the present application disclose a lens device, an electronic device, a method for manufacturing the lens device, and a mask plate. Embodiments of the present application can be applied to electronic devices in different application scenarios. The variable-focus flexible lens device includes a transparent film body made of a light-induced modulus control material. The film body has a lens portion for forming a lens. The elastic modulus of the lens portion is configured to increase or decrease from the center to the periphery. The lens portion can produce corresponding deformation to form a lens with good structural compatibility. In practical applications, on the basis of not affecting the existing main structure of the electronic device, on the one hand, the space occupied in the optical axis direction during the focusing process can be reduced, and the product manufacturing cost can be effectively controlled during the adjustment of the focal length error.

Description

Technical Field

[0001] This application relates to the field of computer hardware, and more particularly to a variable focal length flexible lens device and its fabrication method, a mask for fabricating the lens device, and an electronic device using the lens device. Background Technology

[0002] Traditional optical zoom imaging systems suffer from drawbacks such as complex structure, bulky size, severe mechanical wear, and high manufacturing difficulty, failing to meet the requirements of intelligent optical devices for automated, intelligent, and miniaturized optical zoom systems. Existing technologies have proposed flexible zoom systems to address this issue. Among these, flexible zoom lenses have attracted significant attention.

[0003] Existing flexible zoom lenses typically consist of a transparent elastic film and a transparent fluid medium. They achieve focal length adjustment without mechanical movement along the optical axis, offering advantages such as compact structure, flexible control, low manufacturing cost, no mechanical wear, and ease of integration. Based on the zoom driving mechanism, flexible zoom lenses can be divided into force-induced deformation-driven zoom lenses and electro-induced deformation-driven zoom lenses. Force-induced deformation-driven zoom lenses utilize lateral pressure to compress the rubber film, causing deformation.

[0004] However, the implementation of this scheme is relatively complex, and due to the limitations of its own structure, the focal length change produced under a certain degree of stretching is small, thus limiting its application scenarios. Summary of the Invention

[0005] This application provides a lens device, an electronic device, a method for fabricating the lens device, and a mask. By optimizing the structure of the variable-focus flexible lens device, a larger focusing range is obtained to support different application scenarios.

[0006] The first aspect of this application provides a variable-focus flexible lens device, including a transparent film body made of a photosensitive modulus material. The film body has a lens portion for forming a lens, the elastic modulus of which is configured to increase or decrease from its center outwards. The lens portion can deform accordingly to form a lens. This configuration allows for the control of the modulus's variation with spatial position to achieve concave / convex lenses of different surface shapes. The operability of this zoom method reduces the difficulty of applying flexible zoom lenses in variable-shape optoelectronic devices, thereby expanding the application range of flexible zoom lenses. Simultaneously, the deformable lens portion of the film body has a simple self-structure, fully utilizing the characteristics of the photosensitive modulus material. The lens position and focal length can be defined based on the exposure intensity, resulting in a simple process and low cost. Furthermore, by forming different elastic moduli in the same layer structure, the flexible lens deforms significantly under actuation force, achieving a wide range of focal length changes. Even with small deformation, a large focal length change can be obtained, effectively reducing the space occupied by the lens device in practical applications and exhibiting good structural compatibility.

[0007] For example, by applying an actuating force to the membrane body, the lens portion produces the deformation, and the direction of the actuating force is perpendicular to the optical axis of the lens. In specific applications, a tensile actuating force can be applied to the membrane body, and the lens portion will undergo tensile deformation to form a lens; or, a compressive actuating force can be applied to the membrane body, and the lens portion will undergo compressive deformation to form a lens.

[0008] In some practical applications, focal length variations ranging from infinity to tens of millimeters can be achieved by controlling the modulus as it changes with spatial position.

[0009] In other practical applications, the thickness of the membrane body is 1µm to 1cm. The appropriate thickness can be selected based on the functional requirements of different application scenarios.

[0010] Based on the first aspect, this application also provides a first implementation of the first aspect: the elastic modulus of the lens portion can be configured to increase or decrease in the thickness direction of the film body. This results in a curvature difference between the upper and lower surfaces of the lens after deformation, further enabling the adjustment of the overall refractive power of the lens after deformation.

[0011] Based on the first aspect, or the first embodiment of the first aspect, this application also provides a second embodiment of the first aspect: the elastic modulus of the lens portion is configured to increase or decrease from its center to its outer periphery, wherein the ratio of the maximum elastic modulus to the minimum elastic modulus is 1 to 50. This further makes the deformation of the flexible lens more pronounced during the application of an actuating force.

[0012] Exemplarily, the deformation ratio of the lens part is not greater than 60%.

[0013] In some practical applications, the photoinduced regulation modulus material can be a prepolymer added with a photosensitive component. Exemplarily, the prepolymer can be a PDMS prepolymer, a PP prepolymer or a PET prepolymer, and the photosensitive component can be a photoinitiator or a photo inhibitor.

[0014] In some other practical applications, the photoinduced regulation modulus material can also be an organic modified ceramic having two groups of thermal crosslinking and UV crosslinking.

[0015] Based on the first aspect, or the first implementation manner of the first aspect, or the second implementation manner of the first aspect, the embodiments of the present application further provide a third implementation manner of the first aspect: the lens part is one, and the deformed lens is a convex lens or a concave lens. It can be widely applied to application scenarios such as compact imaging lenses, optical sensors, mobile communication devices or imaging angle compensation, etc., which conforms to the design trend of product thinning.

[0016] Based on the first aspect, or the first implementation manner of the first aspect, or the second implementation manner of the first aspect, the embodiments of the present application further provide a fourth implementation manner of the first aspect: the lens parts are multiple and arranged in an array, and the multiple deformed lenses can all be convex lenses, or all be concave lenses; or, a part of the multiple deformed lenses are convex lenses and the other part are concave lenses. It can be widely applied to application scenarios such as pixel pitch compensation, optical fingerprint sensors, backlight uniformity compensation of display devices or chromatic aberration compensation of imaging systems, etc.

[0017] Based on the first aspect, or the first implementation manner of the first aspect, or the second implementation manner of the first aspect, or the third implementation manner of the first aspect, or the fourth implementation manner of the first aspect, the embodiments of the present application further provide a fifth implementation manner of the first aspect: the ratio of the lens diameter d to the lens focal length f of the convex lens is: 0 < d / f ≤ 0.3, and the ratio of the lens diameter d to the lens focal length f of the concave lens is: -0.3 ≥ d / f > 0. In this way, through the configuration method of increasing or decreasing the elastic modulus of the lens part, on the basis of reasonably controlling the lens size, the application requirements of larger focal length change can be maximally taken into account.

[0018] Exemplarily, the size of the lens is 1um to 1cm.

[0019] A second aspect of this application provides a mask for fabricating the aforementioned variable-focus flexible lens device. This mask has a light transmission control section for controlling the exposure level of the lens portion. The light transmittance of the light transmission control section is configured to increase or decrease from its center outwards. This configuration, by controlling the relationship between the central modulus and the modulus of other peripheral parts, allows for different exposure levels to be provided for different areas of the same lens portion using a single mask, thereby reliably achieving the effect of a convex / concave lens, i.e., achieving patterned modulus control. It features simple processing and low cost.

[0020] For example, the grayscale of the light transmission control section increases or decreases in a stepwise manner to form a light transmittance that decreases or increases from its center to its periphery. Alternatively, the grayscale of the light transmission control section increases or decreases gradually to form a light transmittance that decreases or increases from its center to its periphery. This allows for better subdivision of the grayscale gradient, enabling continuous variation of the modulus of the lens portion on the film body, thus achieving precise control over the lens curvature. In practical applications, the appropriate option can be selected based on the specific functional requirements of the lens.

[0021] A third aspect of this application provides a method for fabricating the aforementioned variable-focus flexible lens device, comprising the following steps: preparing a substrate for a film body using a photosensitive modulus material; exposing the substrate for the film body to exposure, and controlling the exposure intensity using the aforementioned photomask to form a lens portion on the film body. This further reduces product manufacturing costs while reasonably controlling the cost of lens materials.

[0022] For example, the substrate for preparing the film body using the above-mentioned photosensitive modulus material includes the following steps: coating a photosensitive modulus material layer on a glass substrate; annealing in an air atmosphere at 60°C to 150°C to cure the coated photosensitive modulus material layer to form a substrate.

[0023] A fourth aspect of this application provides an electronic device including the aforementioned variable focus flexible lens device.

[0024] Based on the fourth aspect, the present application also provides a first implementation of the fourth aspect: it further includes an actuating component for applying an actuating force to the film body of the variable focal length flexible lens device, so that the lens portion on the film body forms an adjustable focal length lens according to the magnitude of the actuating force.

[0025] In some practical applications, this electronic device is an image acquisition device, which includes an image sensor and an imaging lens system. The film body has a lens portion that can form a convex lens, which can be a convex lens in the imaging lens system. The image sensor is used to sense the light signal transmitted from the imaging lens system and convert the light signal into an electrical signal. The actuating component is a biaxial or multiaxial tensioning frame to provide the stretching actuation force. In this way, the flexible zoom lens is used as a zoom lens in an optical imaging system. By stretching and controlling the film body through a mechanical structure, free zoom within a predefined range can be achieved without adjusting the distance between the lenses in the lens group along the optical axis to change the imaging focal length. Compared with traditional liquid zoom lenses, based on the characteristic of modulus control by spatial position change, on the one hand, the embodiments of this application can make the focal length control of the zoom lens more accurate; on the other hand, adjusting the focal length does not require occupying space in the length direction of the lens group, which can effectively reduce the overall length of the optical imaging system and conform to the design trend of product thinning.

[0026] For example, but not limited to, the stretchable zoom lens can be used as a zoom lens in an imaging system. Alternatively, a variable number of stretchable zoom lenses can be used, partially or entirely, as a lens group in an optical imaging system, serving as multiple zoom lenses in the imaging system.

[0027] In other practical applications, the electronic device is a stretchable display device. This stretchable display device includes an elastic substrate with an array of light-emitting pixels composed of multiple light-emitting pixels. The film body has multiple lens portions that can form a lens array, and the film body is located on the light-emitting side relative to the elastic substrate. The actuating component is constructed from the elastic substrate; that is, during use, the stretched deformation portion of the elastic substrate can simultaneously stretch the lens portions to form lenses. Thus, when the stretchable display device is stretched, the spacing between the light-emitting pixels on its elastic substrate will change accordingly. The lens portions covering the elastic substrate are simultaneously stretched and deformed to form lenses, thereby reducing the dark areas formed between pixels after stretching, thus compensating for the stretched display. In the embodiments of this application, compensation at different angles can be achieved with changes in the stretch ratio; that is, the compensation lens is directly coupled to the stretch ratio of the display device, without additional IC control or power consumption requirements. It features a simple structure and low cost.

[0028] For example, the lens array can be a convex lens array, which is arranged opposite to the light-emitting pixel array, forming a convex lens in the orthographic projection area of ​​the light-emitting pixels whose focal length decreases as the stretch ratio increases; or, the lens array can be a concave lens array, which is staggered with the light-emitting pixel array, forming a concave lens in the orthographic projection area between the light-emitting pixels whose absolute focal length decreases as the stretch ratio increases. Both methods can reduce the dark areas formed between pixels after stretching.

[0029] Based on the fourth aspect, this application also provides a second implementation of the fourth aspect: the membrane body of the variable focus flexible lens device is configured to be actuated, and the lens portion on the membrane body forms a lens with a fixed focal length. This relates to an application scenario where the flexible adjustable focus lens is formed and assembled in a single stretching process.

[0030] In some practical applications, the electronic device can be an optical sensor, which includes an image-side lens device and an image sensor. The film body has multiple lens sections capable of forming a convex lens array, and the formed convex lens array with a fixed focal length is the convex lens array of the image-side lens device. Correspondingly, the image sensor includes multiple light-receiving sections, and the multiple light-receiving sections are arranged opposite to the convex lens array. In this way, based on the characteristic of modulus-controlled lenses with spatial position changes, if the convex lens array has a focusing deviation, the film body can be re-exposed through a patterned illumination process, that is, the modulus of different regions of the lens section can be readjusted, so that the focal length of the stretched and formed convex lens array can accurately focus the light emitted from the image side onto the light-receiving section of the image sensor. Compared with traditional lens processing technology, where the mold for making the lens cannot be reused once the lens array has a focusing error, the embodiments of this application can greatly reduce the manufacturing cost of the lens array.

[0031] In other practical applications, the electronic device can be a display device, which includes a display panel and a backlight device. The backlight device is located on the opposite side of the display side of the display panel. The backlight device includes a backlight cavity and multiple light sources, which are disposed in the backlight cavity. The film body has multiple lens portions that can form a lens array. The formed lens array with a fixed focal length is a lens array disposed in the backlight cavity, and the lens array is arranged opposite to the multiple light sources. With this configuration, when the lens array is configured as a concave lens array disposed in the backlight cavity, the light mixing height of the display device can be reduced, thereby achieving backlight compensation and making the display structure more compact while improving backlight uniformity. When the lens array is configured as a convex lens array disposed in the backlight cavity, the light emission angle of the light source can be reduced, thereby improving the peak brightness of the display device. The embodiments of this application are based on the characteristics of modulus lenses that can be adjusted by spatial position changes. The lens array is fixed after one stretching and forming, which enables the ultra-thin backlight module and reduces the cost.

[0032] In some practical applications, this electronic device can be a light-emitting device, which includes a reflector, a diffuser, and multiple light sources disposed on the reflector. The film body has multiple lens sections capable of forming a lens array, which is a lens array disposed on the light-emitting side of the reflector, with the lenses positioned opposite to the multiple light sources. This configuration allows the constructed light-emitting device to achieve backlight uniformity compensation and a more compact structure. Simultaneously, the lens formed by modulus stretching based on spatial positional adjustments can reliably reduce the light mixing height while lowering costs. Attached Figure Description

[0033] Figure 1 This is a front view of the variable focal length flexible lens device provided in an embodiment of this application;

[0034] Figure 2 for Figure 1 Central cross-sectional view;

[0035] Figure 3 To apply tension actuation Figure 1 A schematic diagram of the concave lens formed by the deformation of the membrane body shown;

[0036] Figure 4 The image shows the results obtained based on COMSOL finite element simulation. Figure 1 The simulation results of the concave lens are shown.

[0037] Figure 5 for Figure 4 A cross-sectional view of the simulation results shown;

[0038] Figure 6 A front view of a variable focal length flexible lens device provided in another embodiment of this application;

[0039] Figure 7 for Figure 6 Central cross-sectional view;

[0040] Figure 8 To apply tension actuation Figure 6 A schematic diagram of the convex lens formed by the deformation of the membrane body shown;

[0041] Figure 9 The image shows the results obtained based on COMSOL finite element simulation. Figure 6 The simulation results of the convex lens are shown.

[0042] Figure 10 The image shown is generated based on LightTools ray tracing simulation. Figure 6 The surface shape fitting results of the lens shown;

[0043] Figure 11 The image shown is generated based on LightTools ray tracing simulation. Figure 6Optical simulation results of the lens shown;

[0044] Figure 12 This is a schematic diagram of a concave lens array provided in an embodiment of this application;

[0045] Figure 13 The image shows the simulation results of a concave lens array formed by biaxial stretching, obtained based on COMSOL finite element simulation.

[0046] Figure 14 A schematic diagram of a photomask provided for an embodiment of this application;

[0047] Figure 15 A schematic diagram of a photomask provided for another embodiment of this application;

[0048] Figure 16 A schematic diagram of a photomask provided for yet another embodiment of this application;

[0049] Figure 17 A schematic diagram of a photomask provided for yet another embodiment of this application;

[0050] Figure 18 A schematic diagram of a photomask provided for yet another embodiment of this application;

[0051] Figure 19 A schematic diagram of a photomask provided for yet another embodiment of this application;

[0052] Figure 20 A schematic diagram of a photomask provided for yet another embodiment of this application;

[0053] Figure 21 This is a schematic diagram of the imaging lens system of the image acquisition device provided in the embodiments of this application;

[0054] Figure 22 and Figure 23 They are shown respectively Figure 21 Schematic diagram of two focal length variations for the imaging lens system shown;

[0055] Figure 24 A schematic diagram of the display device of the stretchable display device provided in the embodiments of this application;

[0056] Figure 25 for Figure 24 The diagram shows the stretched state of the display device.

[0057] Figure 26 A schematic diagram of the display device of the stretchable display device provided in the embodiments of this application;

[0058] Figure 27 for Figure 26 The diagram shows the stretched state of the display device.

[0059] Figure 28 A schematic diagram of a front-illuminated optical sensor provided in an embodiment of this application;

[0060] Figure 29 A schematic diagram of a back-illuminated optical sensor provided in an embodiment of this application;

[0061] Figure 30 A schematic diagram of a display device provided in an embodiment of this application;

[0062] Figure 31 A schematic diagram of a variable focal length flexible lens device provided in an embodiment of this application;

[0063] Figure 32 for Figure 31 A schematic diagram of the lens state after the variable focus flexible lens device is stretched.

[0064] Figure 33 A schematic diagram of a variable focal length flexible lens device provided in an embodiment of this application;

[0065] Figure 34 for Figure 33 The diagram shows the lens state after the variable focus flexible lens device has been stretched. Detailed Implementation

[0066] This application provides a variable focal length flexible lens device with uniform material. By adjusting the elastic modulus distribution of the same layer structure, it can support the function of adjusting the focal length of the lens in different application scenarios. It can achieve focal length changes from infinity to tens of millimeters, and can achieve large focal length changes with small deformation.

[0067] Without loss of generality, the variable focus flexible lens device includes a transparent film body made of a photosensitive modulus material, the film body having a lens portion for forming a lens, and the elastic modulus of the lens portion can be configured to increase or decrease from its center to its outer periphery based on the properties of the photosensitive modulus material; when an actuating force is applied to the film body, the lens portion can produce a corresponding deformation to form a lens; the direction of the actuating force is perpendicular to the optical axis of the lens.

[0068] Here, "transparent film body" refers to a film body material that allows light transmission, including not only allowing light transmission but also allowing image formation through a transparent medium; it also includes a semi-transparent medium that only allows light transmission. It should be understood that any material that meets the functional requirements of the corresponding polarity lens in different application scenarios is acceptable.

[0069] The applied actuating force can cause the membrane body to be subjected to tension or compression, meaning that the lens portion on the membrane body can undergo tensile or compressive deformation. Based on the characteristic that its elastic modulus is distributed from its center to the outer periphery, the two sides of the deformed lens portion will form a certain curved shape. By controlling the change of elastic modulus with spatial position, concave / convex lenses with different surface shapes can be realized, thereby forming lenses with different focal lengths.

[0070] It should be noted that Young's modulus is a physical quantity that defines the ability of a solid material to resist deformation. In this embodiment, Young's modulus, which characterizes the ratio of uniaxial stress to uniaxial deformation, is used as a physical quantity to describe the corresponding distribution of the above-mentioned elastic modulus in space, and based on this, the specific configuration of the lens section is described in detail for different lens types (convex lens, concave lens).

[0071] For the lens portion that forms a convex lens after deformation.

[0072] The Young's modulus of the lens portion is configured to decrease from its center to its outer periphery. By applying a tensile actuating force to the film body, the lens portion is stretched to form a convex lens. Alternatively, the Young's modulus of the lens portion is configured to increase from its center to its outer periphery. By applying a compressive actuating force to the film body, the lens portion is compressed to form a convex lens.

[0073] For the lens portion that forms a concave lens after deformation.

[0074] The Young's modulus of the lens portion is configured to increase from its center to its outer periphery. By applying a tensile actuating force to the film body, the lens portion is stretched to form a concave lens. Alternatively, the Young's modulus of the lens portion is configured to decrease from its center to its outer periphery. By applying a compressive actuating force to the film body, the lens portion is compressed to form a concave lens.

[0075] Based on the relationship between the lens form, the Young's modulus configuration of the lens section, and the tensile and compressive deformation methods described above, this embodiment is based on tensile deformation. The tensile process can be achieved through a biaxial or multiaxial tensioning frame, and the tensile stress generated in the film during tensioning is approximately 0–50 MPa. By controlling the degree of tension, the lens can achieve different focal length variations.

[0076] In this embodiment, the photomodulation material used to prepare the membrane body can be a semi-transparent / transparent elastic modulus adjustable material that can control the modulus of the membrane region through patterned illumination, as needed.

[0077] For example, but not limited to, photomodulation materials can be prepolymers with added photosensitive components. These prepolymers can be PDMS (Polydimethylsiloxane), PP (Plyprpylene), or PET (Polyethylene terephthalate) prepolymers. Specifically, a crosslinking agent can be mixed into the main material to form the corresponding prepolymer. The photosensitive component can be a photopromoter or a photoinhibitor. Alternatively, the photomodulation material can also be an organically modified ceramic with both thermally crosslinked and UV-crosslinked groups, such as those produced by the Fraunhofer Institute. Products, etc.

[0078] Please see Figure 1 , Figure 2 and Figure 3 ,in, Figure 1 This is a front view of a variable focal length flexible lens device according to an embodiment of this application. Figure 2 for Figure 1 Central cross-section view, Figure 3 A schematic diagram of a concave lens formed when a stretching actuation is applied to the membrane body to cause deformation.

[0079] The film body 10 of the variable focus flexible lens device is made of a photosensitive modulus material. The film body 10 has a lens portion 1a for forming a concave lens, which is circular as shown in the figure. In this practical example, the Young's modulus of the lens portion 1a can be configured as follows: Figure 1 As shown, the regions increasing from the center outwards are, respectively, a low-modulus region 11a, a medium-modulus region 12a, and a high-modulus region 13a, forming a smooth film body 10 before stretching. Thus, when a stretching force is applied bidirectionally to the film body 10, the lens portion 1a deforms accordingly, reducing the absolute value of the radius of the two curved surfaces, forming a shape as shown... Figure 3 The concave lens shown; of course, the direction of the actuating force is perpendicular to the optical axis of the concave lens.

[0080] In practical applications, the thickness of the film body 10 can be from 1µm to 1cm. In the Young's modulus configuration of the lens section 1a, the ratio of the maximum elastic modulus to the minimum elastic modulus can be from 1 to 50 to support the manufacturing of large-scale (centimeter-level lenses, up to 1cm) and small-scale (micrometer-level lenses, down to 1µm) lenses, and the specific selection can be made according to the functional requirements of different products. The deformation ratio of the lens section is no greater than 60%. Here, "deformation ratio" refers to the ratio of the change in the size of the lens section area before deformation to the change in the area of ​​the lens formed by deformation.

[0081] For example, but not limited to, performing optical simulations of topographic changes in a configuration where the ratio of the maximum to the minimum modulus in an increasing modulus variation is 10. Please also refer to... Figure 4 and Figure 5 ,in, Figure 4 The image shows the simulation results of a concave lens formed by biaxial stretching, obtained through finite element simulation using COMSOL (simulation software). Figure 5 for Figure 4 The diagram shows a cross-sectional view of the simulation results. It can be seen that the Young's modulus configuration of the lens section 1a can be designed according to the required focal length variation range. Specifically, the ratio of the lens diameter d to the lens focal length f of the concave lens is -0.3 ≥ d / f > 0, which can meet the needs of different application scenarios.

[0082] Among them, based on a concave lens with an aperture of 368mm, simulations were performed for three different Young's modulus configurations of the lens section. The simulation results are shown in Table 1 below:

[0083]

[0084] Please see Figure 6 , Figure 7 and Figure 8 ,in, Figure 6 This is a front view of a variable focal length flexible lens device according to another embodiment of this application. Figure 7 for Figure 6 Central cross-section view, Figure 8 A schematic diagram of a convex lens formed when a stretching actuation is applied to the membrane body to cause deformation.

[0085] The film body of the variable-focus flexible lens device is made of a photosensitive modulus material. The film body 10 has a lens portion for forming a convex lens; the lens portion 1b shown in the figure is circular. In this practical example, the Young's modulus of the lens portion 1b can be configured as follows: Figure 6 As shown, the region decreases from its center outwards, consisting of a high-modulus region 13b, a medium-modulus region 12b, and a low-modulus region 11b, respectively. Before stretching, it is also a flat film body 10. Thus, when a stretching force is applied to the film body 10 in both directions, the lens portion 1b can undergo corresponding deformation, and the absolute value of the radius of the two curved surfaces decreases, forming a shape as shown in the image. Figure 6 The convex lens shown.

[0086] In specific applications, the Young's modulus configuration range of the lens section 1b can be the same as that of the previous embodiment, and can be selected according to the functional requirements of different products.

[0087] For example, but not limited to, performing optical simulations of topographic changes in a configuration where the ratio of the maximum to the minimum modulus in an increasing modulus variation is 10. Please also refer to... Figure 9 , Figure 10 and Figure 11 , wherein Figure 9 shows the simulation results of a convex lens formed by biaxial stretching obtained based on COMSOL finite element simulation. Figure 10 shows the lens surface fitting results formed by ray tracing simulation based on LightTools (optical modeling software). Figure 11 shows the optical simulation results formed by ray tracing simulation based on LightTools. It can be seen that the focal length of the convex lens can be adjusted according to different stretching driving forces to form different light transmissions. Specifically, the ratio of the lens diameter d to the lens focal length f of the convex lens is: 0 < d / f ≤ 0.3, which can meet the needs of different application scenarios.

[0088] The variable focal length flexible lens devices provided in the above two embodiments are both in the form of a single lens. According to the concept of the present invention, a lens array can also be formed.

[0089] Among them, based on a convex lens with an aperture of 368 mm, simulations are respectively carried out for three configuration methods of the Young's modulus of the lens part, and the simulation results are shown in Table 2 below:

[0090]

[0091] Please refer to Figure 12 , which shows a schematic diagram of a concave lens array provided by an embodiment of the present application. The figure shows a part of the concave lens array.

[0092] The film body of the variable focal length flexible lens device is made of a photoinduced regulated modulus material. The film body 1 has a plurality of lens parts 1c for forming concave lenses. The lens part 1a shown in the figure is circular. In this practical example, the Young's modulus of each lens part 1c can be configured to increase from its center to the periphery, specifically the same as the Figure 1 principle schematic diagram of the shown embodiment. In this way, when a stretching driving force is applied bidirectionally or multi-directionally to the film body 10, each lens part 1c can generate a corresponding deformation, forming a concave lens array as shown in Figure 12 .

[0093] For example but not limited to, each lens part 1c is configured with a ratio of the maximum modulus to the minimum modulus of 10 in the increasing modulus change, and a topographic change optical simulation is carried out. Please also refer to Figure 13 , which shows the simulation results of a concave lens array formed by biaxial stretching obtained based on COMSOL (simulation software) finite element simulation.

[0094] It can be understood that Figure 12 in the concave lens array formed by the deformation shown in, the same stretching ratio - focal length relationship is periodically formed for each lens; in some specific applications, different focal length relationships and polarities of lens arrangements can also be formed in a non-periodic distribution form (not shown in the figure).

[0095] In other specific applications, the multiple lenses formed by deformation in a lens array can all be convex lenses, that is, a convex lens array is formed by deformation. Alternatively, some of the multiple lenses formed by deformation can be convex lenses and others can be concave lenses; that is to say, the lens array formed by deformation is not limited to lenses of the same polarity.

[0096] This embodiment provides a process method for manufacturing the aforementioned variable focal length flexible lens device, which mainly includes the following steps:

[0097] S41. Add the corresponding photosensitive component to PDMS, such as, but not limited to, benzophenone with photoinhibition ability, to form PP-PDMS prepolymer;

[0098] S42. After the glass substrate is silanized and cleaned, the PP-PDMS prepolymer is coated on the glass substrate, and the thickness of the prepolymer is controlled to be 1μm to 1cm. In addition, depending on the actual process conditions, the blade coating, spray coating, spin coating or slot coating process can be selected.

[0099] S43. Annealing in an air atmosphere at 60℃~150℃ for 10min~144h to cure the prepolymer and form a PP-PDMS film substrate;

[0100] S44. The PP-PDMS film substrate placed on the glass substrate is exposed, for example, but not limited to, by irradiation with 380nm UV light (ultraviolet light). In other specific applications, other light sources may be used for exposure. During the irradiation process, the exposure position of the film substrate is controlled by a mask. The area irradiated with UV light causes a light suppression effect, resulting in a decrease in modulus, which is negatively correlated with the degree of exposure. This results in different modulus values ​​in different areas, thereby achieving patterned modulus control and forming a lens portion with increasing or decreasing Young's modulus.

[0101] S45. Peel the PP-PDMS film body off the glass substrate.

[0102] In this way, the shape of the lens changes due to the biaxial stretching of the thin film at its edge, and the surface of the lens forms a curved surface with the modulus difference mentioned above, thus forming an optical lens.

[0103] Compared to existing variable focal length lens solutions, which are complex in structure, have inaccurate focal length control, and are easily affected by the external environment, the optical lens prepared using this embodiment can change its focal length with the change of the stretching ratio. In other words, the focal length adjustment is only limited by the stretching ratio of the lens part on the film body, which has the advantages of better precision controllability and simple structure.

[0104] It should be noted that the UV light is preferably a collimated light source. In this way, the light absorption of the film material by the exposure light source is negligible, and the curved surfaces on both sides that meet the accuracy requirements can be obtained.

[0105] This application also provides another process for preparing the aforementioned variable focal length flexible lens device. The main difference between this method and the previous method is that different prepolymer materials and photosensitive components are used.

[0106] S51. Mix polymer monomers such as PP or PET with a crosslinking agent to form the corresponding prepolymer; in addition to diphenyl ketone, other additives may be used as photopromoters or photoinhibitors, including but not limited to 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) for initiating the polymerization of hexanediol diacrylate (HDDA); and 2'-hydroxy-4',5'-dimethylacetylbenzene (HP-8) for initiating the polymerization of 2-ethylhexyl acrylate (2-EHA), acrylic acid (AA) and butyl acrylate (BA).

[0107] Specifically, when using a photoinhibitor, the modulus at the corresponding location is reduced by increasing the exposure level; when adding a photoaccelerator, the modulus at the corresponding location is increased by increasing the exposure level.

[0108] In practical applications, the photosensitive components added to the prepolymer can be various photosensitive materials with different response wavelengths. When multiple photosensitive materials (which may include both photopromoters and photoinhibitors) are used as additives, different photosensitive materials can be activated by exposure at different wavelengths in stages. This allows for the independent enhancement or reduction of the modulus in different regions of the thin film using different masks. This setup can further improve the modulus range of the thin film and expand the focal length adjustment range of the lens.

[0109] S52. In addition to coating, prepolymer film layers can also be prepared by spin coating, blade coating, inkjet printing, screen printing and other processes;

[0110] S53. Depending on the different polymer materials, the temperature range of the thermosetting process of the film substrate can be 60℃~150℃, the curing atmosphere can be [missing information], and the specific annealing and curing time range can be 10min~144h.

[0111] S54. The wavelength of the light source for the exposure process can be 100nm to 400nm; in practical applications, the specific exposure level can be achieved by controlling the exposure time and / or the exposure intensity.

[0112] S55. Peel the film body formed in step S54 off the glass substrate.

[0113] Depending on the shape and specific requirements of the film, the film body can be stretched using uniaxial / multiaxial stretching or multi-point fixed stretching to form a lens.

[0114] In view of the above-mentioned process method, an embodiment of this application provides a schematic diagram of a photomask.

[0115] Please see Figure 14 The photomask 20 has a light transmission control section 2a for controlling the exposure level of the lens portion. The light transmission control section 2a has a transmittance that decreases from its center to its periphery, making it suitable for fabricating grayscale photomasks of circular concave lenses using photosensitive modulus materials with added light inhibitors in the prepolymer. Here, transmittance represents the ability of light to pass through a medium; it is the percentage of light flux transmitted through a transparent or translucent body relative to the incident light flux, i.e., it can represent the efficiency of light transmission of the photomask. For example, but not limited to, it can be used to fabricate the variable-focus flexible lens device described in Embodiment 1. Different grayscale values ​​correspond to different optical transmittance ranges within the wavelength range of the exposure light source; that is, the smaller the grayscale value, the higher its transmittance.

[0116] As shown in the figure, the exposure intensity is highest at the center of the concentric circles of the mask 20 and lowest at the periphery. The transmittance of different grayscale regions on the mask 20 from the center to the edge for the exposure light source (such as a 380nm wavelength light source) is 100% (grayscale 0), 50% (grayscale 128), 25% (grayscale 191), and 0% (grayscale 255), respectively. Here, "grayscale" refers to linearly encoded grayscale to characterize the corresponding transmittance; it can be understood that "grayscale" in nonlinear spaces such as sRGB can also be used to characterize transmittance.

[0117] Therefore, different exposure levels in different areas of the light transmission control section 2a can be achieved simultaneously using a single mask. In other words, the grayscale of the light transmission control section 2a increases in a stepwise manner to form a light transmittance that decreases from its center to its periphery.

[0118] This application also provides a schematic diagram of another mask, please refer to [link to schematic diagram]. Figure 15 .

[0119] The photomask 20 has a light transmission control section 2b for controlling the exposure level of the lens portion. The light transmission control section 2b is configured to increase in transmittance from its center to its outer periphery, making it suitable for fabricating grayscale photomasks for circular convex lenses using photosensitive modulus materials with added light inhibitors in the prepolymer. For example, but not limited to, it can be used to fabricate the variable focus flexible lens device described in Embodiment 2.

[0120] As shown in the figure, the exposure intensity is lowest at the center of the concentric circles of the mask 20 and highest at the periphery. The transmittance of different grayscale regions on the mask from the center to the edge to the exposure light source (such as a 380nm wavelength light source) is 0% (grayscale 255), 25% (grayscale 191), 50% (grayscale 128), and 100% (grayscale 0), respectively.

[0121] In this way, different exposure levels in different areas of the light transmission control section 2b can be achieved simultaneously using a single mask. That is, the grayscale of the light transmission control section 2b decreases in a stepwise manner to form a light transmittance that increases from its center to its periphery.

[0122] The photomasks provided in the two embodiments described above both have light transmission control sections used to form circular lenses. In specific applications, based on the pattern shape of the photomask, non-circular irregular lenses can also be fabricated.

[0123] Please see Figure 16 The figure shows a schematic diagram of another type of mask provided in this embodiment.

[0124] The photomask 20 has a light transmission control section 2c for controlling the exposure level of the hexagonal lens portion. The light transmission control section 2c is configured to decrease from its center to its outer periphery, making it suitable for fabricating grayscale photomasks of hexagonal concave lenses using photomodulated modulus materials with added light inhibitors in the prepolymer.

[0125] As shown in the figure, the exposure intensity is highest at the center of the concentric hexagon of the mask 20 and lowest at the periphery. The transmittance of different grayscale regions on the mask from the center to the edge for the exposure light source (such as a 380nm wavelength light source) is 100% (grayscale 0), 75% (grayscale 64), 50% (grayscale 128), 25% (grayscale 191), and 0% (grayscale 255), respectively.

[0126] Please see Figure 17 The figure shows a schematic diagram of another type of mask provided in this embodiment.

[0127] The photomask 20 has a light transmission control section 2d for controlling the exposure level of the hexagonal lens portion. The light transmission control section 2c is configured to decrease in transmittance from its center to its outer periphery, making it suitable for fabricating grayscale photomasks of hexagonal convex lenses using photomodulated modulus materials with added light inhibitors in the prepolymer.

[0128] As shown in the figure, the exposure intensity is lowest at the center of the concentric hexagon of the mask 20 and highest at the periphery. The transmittance of different grayscale regions on the mask from the center to the edge to the exposure light source (such as a 380nm wavelength light source) is 0% (grayscale 255), 25% (grayscale 191), 50% (grayscale 128), 75% (grayscale 64), and 100% (grayscale 0), respectively.

[0129] Please see Figure 18 The figure shows a schematic diagram of another type of mask provided in this embodiment.

[0130] The photomask 20 has a light transmission control section 2e for controlling the exposure level for forming the freeform lens portion. The light transmission control section 2e is configured to increase in transmittance from its center to its periphery, making it suitable for fabricating grayscale photomasks for freeform convex lenses using photomodulated modulus materials with added light inhibitors in the prepolymer. As shown in the figure, the exposure intensity is lowest at the center of the photomask 20 and highest at the periphery.

[0131] The above Figures 14 to 18 The mask provided in the illustrated embodiment has a grayscale of the light transmission control section that increases or decreases in a step-like manner. In specific applications, the grayscale of the light transmission control section can also increase or decrease gradually to form a light transmittance that decreases or increases from its center to its periphery.

[0132] Please see Figure 19 The figure shows a schematic diagram of another type of mask provided in this embodiment.

[0133] The photomask 20 has a light transmission control section 2f for controlling the exposure level of the lens portion. The light transmission control section 2f is configured to increase from its center to its outer periphery, making it suitable for fabricating grayscale photomasks of circular convex lenses using photosensitive modulus materials with added light inhibitors in the prepolymer.

[0134] As shown in the figure, the exposure intensity is lowest at the center of the concentric circles of the photomask 20 and highest at the periphery. The grayscale on the photomask decreases gradually from the center to the edge, and correspondingly, the transmittance to the exposure light source increases gradually.

[0135] Specifically, a Halftone scheme can be used to control local illumination intensity. This scheme consists of black dots with a grayscale value of 0; the larger the volume or the denser the arrangement of the black dots, the lower the exposure intensity of the corresponding area. Compared to the aforementioned methods that achieve grayscale levels in a step-like increase or decrease, this embodiment provides a gradual increase or decrease in grayscale levels, which can better subdivide the grayscale gradient, allowing for continuous variation in the modulus of the lens portion on the film body, thus achieving precise control over the lens curvature.

[0136] Please see Figure 20The figure shows a schematic diagram of another type of mask provided in this embodiment.

[0137] The mask 20 has multiple light transmission control sections 2g for controlling the exposure level of forming multiple lens sections. The grayscale of each light transmission control section 2g decreases in a stepwise manner, that is, the light transmittance of the light transmission control section 2g is configured to increase from its center to its outer periphery. This is suitable for preparing grayscale masks for convex lens arrays using photomodulated modulus materials with added light inhibitors in the prepolymer.

[0138] As shown in the figure, multiple light-transmitting control units 2g are arranged in a circular-hexagonal-circular pattern, which allows for the fabrication of convex lens arrangements of different shapes. In specific applications, multiple light-transmitting control units can adopt the same shape or a combination of other different shapes, depending on the needs of the specific application scenario.

[0139] It should be noted that the above Figures 14 to 20 The photomasks provided in the illustrated embodiments all use photoinhibitors added to the prepolymer as photomodulation modulus materials. For specific applications where photopromoters are added to the prepolymer as photomodulation modulus materials, the resulting lenses have opposite polarities.

[0140] Furthermore, by adding more than one photosensitive component to a photomodulation material, more complex optical lens morphologies can be formed. As described in the preceding embodiments, when multiple photosensitive materials (which may simultaneously include photopromoters and photoinhibitors) are used as additives, different photosensitive materials can be activated by exposure at different wavelengths in stages. This allows for the independent enhancement or reduction of the modulus in different regions of the thin film using different masks, thereby expanding the focal length adjustment range of the lens.

[0141] Please see Figure 21 The figure shows a schematic diagram of the imaging lens system of an image acquisition device according to an embodiment of this application.

[0142] The image acquisition device includes an image sensor 211 and an imaging lens system. In this embodiment, it employs... Figure 6 The variable-focus flexible lens device provided in the illustrated embodiment serves as a component of an imaging lens system. Specifically, the film body 212 of this variable-focus flexible lens device has a lens section, and the formed convex lens, together with other optical elements 213, constitutes the imaging lens system.

[0143] The image sensor 211 is used to sense the light signal transmitted by the self-imaging lens system and convert the light signal into an electrical signal.

[0144] The actuating component applies an actuating force to the film body 212 of the variable-focus flexible lens device, causing the lens portion on the film body to form a lens with an adjustable focal length according to the magnitude of the actuating force, for example, but not limited to... Figure 22 and Figure 23 Two focal length variations are shown respectively. The actuating component (not shown in the figure) can be a dual-axis tensioning frame or a multi-axis tensioning frame, and can be implemented using different mechanical mechanisms, such as, but not limited to, using shape memory alloys or rigid structural components as the tensioning actuating component, as long as it can control the tensioning of the film body 212 and achieve free zoom within a predefined range.

[0145] It is understandable that the application of variable-focus flexible lens devices in imaging lens systems is not limited to the single-layer stretchable lens shown in the figure. In specific applications, multiple stretchable lenses can be used to partially or completely replace the lens group in a traditional optical imaging system.

[0146] based on Figure 21 The imaging lens system provided in the illustrated embodiment can be applied to electronic devices such as cameras, smartphones, tablets, laptops, smart displays, and AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) products.

[0147] The AR / VR / MR head-mounted display uses a zoom component to control the refractive power of the eyepiece system, thereby adjusting the depth of the virtual image. In this embodiment, the zoom component used in this type of adaptive zoom head-mounted display is combined with a conventional fixed-curvature optical lens. By stretching the zoom component, the optical depth of the image is adjusted.

[0148] Please see Figure 24 The figure shows a schematic diagram of a display device of a stretchable display device according to an embodiment of this application.

[0149] The stretchable display device includes an elastic substrate 241 and a film body 242 integrated with the elastic substrate 241, constituting a display device. In this embodiment, a stretchable display device is used. Figure 12 The convex lens array described in the illustrated embodiment serves as a dark area compensation lens for the display device.

[0150] As shown in the figure, the film body 242 is located on the light-emitting side relative to the elastic substrate 241. The elastic substrate 241 has a light-emitting pixel array composed of multiple light-emitting pixels 243. The film body 241 has multiple lens portions that can form a convex lens array, and the convex lens array is arranged opposite to the light-emitting pixel array; that is, there is a one-to-one correspondence between the convex lens and the light-emitting pixel 243. Before stretching, the spacing between the light-emitting pixels 243 is... Figure 24 At the preset distance shown, there is no obvious dark area in the light emission; when the display device is stretched, a convex lens 244 can be formed in the orthogonal projection area of ​​the light-emitting pixel, with the focal length decreasing as the stretching ratio increases, and as shown... Figure 25 The diagram shows a one-to-one correspondence, thereby reducing the dark areas formed between pixels after stretching.

[0151] Here, the actuation force for forming the convex lens array is provided by the deformable elastic substrate 241 or a structure that stretches synchronously with the elastic substrate 241. That is, in this embodiment, the actuation component is constructed from the self-stretching structure of the display device. For example, but not limited to, it is applied to flexible display devices with foldable and stretchable screens.

[0152] Please see Figure 26 This figure shows a schematic diagram of the display device of a stretchable display device according to another embodiment of this application. Figure 24 Compared with the illustrated embodiment, the difference in this embodiment is that the membrane body 262 has multiple lens portions that can form a concave lens array.

[0153] The stretchable display device includes an elastic substrate 261 and a film body 262 integrated with the elastic substrate 261, constituting a display device. In this embodiment, a stretchable display device is used. Figure 12 The concave lens array described in the illustrated embodiment serves as a dark area compensation lens for the display device.

[0154] Similarly, the film body 262 is located on the light-emitting side relative to the elastic substrate 261. The elastic substrate 261 has a light-emitting pixel array composed of multiple light-emitting pixels 263, and the film body 261 has multiple lens portions capable of forming a concave lens array. The concave lens array and the light-emitting pixel array are staggered, meaning that the interval regions between the concave lenses and the light-emitting pixels 263 correspond one-to-one.

[0155] Before stretching, the spacing between the 243 luminescent pixels is Figure 26 The preset distance shown indicates that when the display device is stretched, a concave lens 264 is formed in the orthogonal projection area of ​​the light-emitting pixel spacing, where the absolute value of the focal length decreases as the stretching ratio increases, and as shown... Figure 27 The diagram shows a one-to-one correspondence, thereby reducing the dark areas formed between pixels after stretching.

[0156] Similarly, the actuation force for forming the concave lens array is provided by the deformable elastic substrate 261 or a structure that is stretched synchronously with the elastic substrate 261. That is, in this embodiment, the actuation component is constructed by the self-stretching structure of the display device.

[0157] The above Figure 21 , Figure 24 and Figure 26 The electronic device provided in the illustrated embodiment uses a variable-focus flexible lens device whose focal length can be adjusted according to its shape, and its lens function is realized based on the provided dynamic actuation force. In other specific applications, a variable-focus flexible lens device with a fixed focal length after deformation can also be used.

[0158] Please see Figure 28 The figure shows a schematic diagram of a front-illuminated optical sensor according to an embodiment of this application.

[0159] This optical sensor is a front-illuminated optical sensor that collects incident light information using microlenses, including an image-side lens device 281 and an image sensor 282. In this embodiment, it employs... Figure 12 The convex lens array described in the illustrated embodiment serves as the image-side lens device 281 of the optical sensor.

[0160] As shown in the figure, the membrane body of the image-side lens device 281 has multiple lens portions that can form a convex lens array, and is fixed after stretching. During assembly, the membrane body is configured to be actuated, and the lens portions thereon are deformed to form convex lenses with a fixed focal length.

[0161] The film body is coated on the dielectric layer 284 of the image sensor 282, and its base layer 285 is located inside the dielectric layer. Multiple metal electrodes 283 are embedded in the dielectric layer and the base layer to form multiple light-receiving parts, and each light-receiving part corresponds to a convex lens. For example, but not limited to, it can be used as an under-display optical fingerprint sensor.

[0162] Please see Figure 29 The figure shows a schematic diagram of a back-illuminated optical sensor provided in an embodiment of this application.

[0163] and Figure 28 Compared to the illustrated embodiment, this optical sensor is a back-illuminated optical sensor that collects incident light information using microlenses, including an image-side lens device 291 and an image sensor 292. In this embodiment, a back-illuminated optical sensor is used. Figure 12 The convex lens array described in the illustrated embodiment serves as the image-side lens device 291 of the optical sensor.

[0164] As shown in the figure, the film body of the image-side lens device 291 is stretched and fixed on the base layer 294 of the image sensor 292. Its dielectric layer 295 is located inside the base layer 294. Multiple metal electrodes 293 are embedded in the dielectric layer and the base layer to form multiple light-receiving parts, and each light-receiving part corresponds to a convex lens.

[0165] It should be noted that the basic working principle of front-illuminated and back-illuminated optical sensors is not the core inventive point of this invention, so it will not be elaborated here.

[0166] Please see Figure 30 The figure shows a schematic diagram of a display device according to an embodiment of this application.

[0167] The display device includes a metal electrode 301 and a backlight device 302, wherein the backlight device 302 is disposed on the opposite side of the display side of the metal electrode 301. Here, "display side" refers to the side of the metal electrode 301 facing the user, and "opposite side" refers to the rear side away from the user. It should be understood that the use of the above directional terms is only for clearly describing the positional relationship between the components or structures of the technical solution, and does not constitute a substantial limitation on this solution.

[0168] The backlight device 302 includes a backlight cavity 303 and a plurality of light sources 304. The plurality of light sources 304 are disposed in the backlight cavity 303, which is formed by a reflective sheet 308. In this embodiment, a backlight device is used. Figure 12 The concave lens array 305 described in the illustrated embodiment serves as a backlight uniformity compensation lens for the display device.

[0169] As shown in the figure, after the membrane body is stretched and fixed, the lens portion on it is deformed to form a concave lens 309 with a fixed focal length. The formed concave lens array 305 is a concave lens array set in the backlight cavity 303, and the concave lens corresponds one-to-one with the light source 304.

[0170] For example, but not limited to, the metal electrode 301 can be a liquid crystal panel, and the light source 304 can be an LED. In this embodiment, by providing a concave lens array 305, the light mixing height of the LED can be reduced, thereby making the structure of the display device more compact.

[0171] It should be understood that the direct-lit LED backlight shown in the figure is only a preferred illustration. Panels using side-lit backlights can also use the same concave lens array as a backlight uniformity compensation lens.

[0172] In addition, based on Figure 30 The display device shown can have its concave lens array replaced with a convex lens array (not shown) to reduce the light emission angle of the LEDs and improve the peak brightness of the display device. For example, but not limited to, it can be used in the LCD backlight module of an automotive head-up display.

[0173] Furthermore, the backlight uniformity of this display device can be further improved by employing the diffuser plate 306 and diffuser sheet 307 shown in the figure. In specific applications, based on this display device, the following steps are taken: Figure 30 The display panel shown can be used with light-emitting devices that produce uniform light emission, such as, but not limited to, LED panels.

[0174] It can be determined that the variable-focus flexible lens device provided in this embodiment has good structural compatibility and can repeatedly adjust the modulus configuration as needed. In practical applications, without affecting the main structure of existing electronic devices, it can reduce the space occupied in the optical axis direction during focusing and effectively control product manufacturing costs during the adjustment of focusing errors.

[0175] Please see Figure 31 The figure illustrates this application. Figure 13 The illustrated embodiment provides a schematic diagram of a variable focal length flexible lens device.

[0176] and Figure 6 Compared to the illustrated embodiment, the variable focus flexible lens device provided in this embodiment further has its Young's modulus of the lens portion on the film body configured to increase in the thickness direction of the film body. For example... Figure 31 As shown, the variable focus flexible lens device is formed by exposure under the illumination of a collimating light source. Taking the light absorption rate of the film body material to the collimating light source as 50% as an example, the change in the transmittance of the lens portion to the exposure light source in the thickness direction is shown, thereby forming that the Young's modulus of the lens portion increases in the thickness direction.

[0177] Thus, after stretching and deformation, the resulting convex lens has a difference in curvature between its upper and lower surfaces, such as... Figure 32 As shown, it has the ability to adjust the overall refractive power of the lens after deformation.

[0178] Please see Figure 33 The figure shows a schematic diagram of a variable focal length flexible lens device provided in another embodiment of this application.

[0179] and Figure 6 Compared to the illustrated embodiment, the variable focal length flexible lens device provided in this embodiment, such as Figure 33 As shown, the variable focus flexible lens device is formed by exposure under the illumination of a Lambertian light source without the use of a mask. Due to the larger modulus distribution gradient in the near light source region (upper part of the schematic diagram) and the smaller modulus distribution gradient in the far light source region (lower part of the schematic diagram), the Young's modulus of the lens part increases in the thickness direction.

[0180] After stretching and deformation, the resulting convex lens has a difference in curvature between its upper and lower surfaces, such as... Figure 34 As shown.

[0181] In addition, based on Figure 31 and Figure 33 In the embodiment shown, the specific implementation of the increasing Young's modulus of the lens portion in the thickness direction can also be achieved by combining the absorption effect of the film body material on the exposure light source with the non-collimation of the exposure light source (including but not limited to the Lambert light source).

[0182] It should be noted that, in the embodiments of the present invention, the lens formed by the increasing variation of the Young's modulus of the lens portion in the thickness direction is not limited to... Figure 32 and Figure 34 The convex lens shown can also form a concave lens. The specific implementation principle is the same as described above, and will not be repeated here.

[0183] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A variable-focus flexible lens device, characterized in that, It includes a transparent film body made of a photo-induced modulus regulating material, and the film body has a lens part for forming a lens; The elastic modulus of the lens part is configured to increase or decrease from its center to the periphery; the lens part can generate corresponding deformation to form a lens; by applying a driving force to the film body, the lens part generates the deformation, and the application direction of the driving force is perpendicular to the optical axis of the lens.

2. The variable focal length flexible lens device according to claim 1, characterized in that, The elastic modulus of the lens part is also configured to increase or decrease in the thickness direction of the film body.

3. The variable-focus flexible lens device according to claim 1 or 2, wherein Applying a tensile driving force to the film body, the lens part generates tensile deformation to form the lens; Alternatively, applying a compressive driving force to the film body, the lens part generates compressive deformation to form the lens.

4. The variable focal length flexible lens device according to any one of claims 1 to 3, characterized in that, The elastic modulus of the lens part is configured to increase or decrease from its center to the periphery, wherein the ratio of the maximum elastic modulus to the minimum elastic modulus is 1 to 50.

5. The variable focal length flexible lens device according to claim 4, characterized in that, The thickness of the film body is 1 um to 1 cm.

6. The variable focal length flexible lens device according to any one of claims 1 to 5, characterized in that, The photo-induced modulus regulating material is a prepolymer added with a photosensitive component, or the photo-induced modulus regulating material is an organically modified ceramic having both thermal cross-linking and UV cross-linking groups.

7. The variable focal length flexible lens device according to claim 6, characterized in that, The prepolymer is a PDMS prepolymer, a PP prepolymer or a PET prepolymer, and the photosensitive component is a photo-promoter or a photo-inhibitor.

8. The variable focal length flexible lens device according to any one of claims 1 to 7, characterized in that, There is one lens part, and the formed lens is a convex lens or a concave lens.

9. The variable focal length flexible lens device according to any one of claims 1 to 7, characterized in that, The lens parts are arranged in an array. All the formed lenses are convex lenses or concave lenses; Alternatively, some of the formed lenses are convex lenses and the other part are concave lenses.

10. The variable focal length flexible lens device according to claim 8 or 9, characterized in that, For the convex lens, the ratio of the lens diameter d to the lens focal length f is: 0 < d / f ≤ 0.3, and for the concave lens, the ratio of the lens diameter d to the lens focal length f is: -0.3 ≥ d / f > 0.

11. A mask for fabricating the variable focal length flexible lens device according to any one of claims 1 to 10, characterized in that, The mask plate has a light transmission control part, and the light transmission control part is used to control the exposure degree of forming the lens part, and the light transmittance of the light transmission control part is configured to increase or decrease from its center to the periphery.

12. The photomask according to claim 11, characterized in that, The gray scale of the light transmission control part increases or decreases in a stepped manner to form a light transmittance that decreases or increases from its center to the periphery.

13. The photomask according to claim 11, characterized in that, The gray scale of the light transmission control part increases or decreases in a gradient manner to form a light transmittance that decreases or increases from its center to the periphery.

14. A method for manufacturing the variable focal length flexible lens device according to any one of claims 1 to 10, characterized in that, It includes the following steps: Preparing a substrate of the film body using a photo-induced modulus regulating material; Performing an exposure treatment on the substrate of the film body and controlling the exposure intensity using the mask plate according to any one of claims 11 to 13 to form the lens part on the film body.

15. The method for preparing a variable-focus flexible lens device according to claim 14, characterized in that, The preparing a substrate of the film body using a photo-induced modulus regulating material includes the following steps: Coating a layer of photo-induced modulus regulating material on a glass substrate; Annealing in an air atmosphere at 60 °C to 150 °C to cure the coated layer of photo-induced modulus regulating material to form the substrate.

16. An electronic device, characterized in that, It includes the variable-focus flexible lens device according to claim 1.

17. The electronic device according to claim 16, characterized in that, It also includes an actuating component for applying an actuating force to the film body of the variable focal length flexible lens device, so that the lens portion on the film body forms an adjustable focal length lens according to the magnitude of the actuating force.

18. The electronic device according to claim 17, characterized in that, The electronic device is an image acquisition device, which includes an image sensor and an imaging lens system; The membrane body has a lens portion that can form a convex lens, and the formed convex lens is the convex lens in the imaging lens system. The image sensor is used to sense the light signal transmitted from the imaging lens system and convert the light signal into an electrical signal. The actuating component is a biaxial tension frame or a multiaxial tension frame.

19. The electronic device according to claim 17, characterized in that, The electronic device is a stretchable display device, which includes an elastic substrate and an array of light-emitting pixels consisting of multiple light-emitting pixels. The film body has a plurality of lens portions that can form a lens array, and the film body is located on the light-emitting side relative to the elastic substrate; The actuating component is constructed from the elastic substrate.

20. The electronic device according to claim 19, characterized in that, The lens array is a convex lens array, and the convex lens array is arranged opposite to the light-emitting pixel array; Alternatively, the lens array may be a concave lens array, and the concave lens array and the light-emitting pixel array may be arranged alternately.

21. The electronic device according to claim 16, characterized in that, The membrane body of the variable focal length flexible lens device is configured to be actuated, and the lens portion on the membrane body forms a lens with a fixed focal length.

22. The electronic device according to claim 21, characterized in that, The electronic device is an optical sensor, which includes an image-side lens device and an image sensor. The film body has a plurality of lens portions that can form a convex lens array, and the formed convex lens array is the convex lens array of the image-side lens device; The image sensor includes multiple light-receiving parts, which are arranged opposite to the convex lens array.

23. The electronic device according to claim 21, characterized in that, The electronic device is a display device, which includes a display panel and a backlight device. The backlight device is disposed on the opposite side of the display side of the display panel. The backlight device includes a backlight cavity and multiple light sources, and the multiple light sources are disposed in the backlight cavity. The film body has a plurality of lens portions that can form a lens array. The formed lens array is a lens array disposed in the backlight cavity, and the lens array is disposed opposite to the plurality of light sources.

24. The electronic device according to claim 22, characterized in that, The lens array is either a convex lens array or a concave lens array.

25. The electronic device according to claim 20, characterized in that, The electronic device is a light-emitting device, which includes a reflective sheet, a diffuser plate, and multiple light sources disposed on the reflective sheet; The film body has multiple lens sections that can form a lens array. The formed lens array is a lens array disposed on the light-emitting side of the reflective sheet, and the lens array is disposed opposite to the multiple light sources.

Images