Multi-fold periscopic prism capable of realizing high-power optical zooming and processing method of multi-fold periscopic prism

Abstract

The invention discloses a multi-fold periscopic prism capable of realizing high-power optical zooming and a processing method of the multi-fold periscopic prism. According to the invention, a semiconductor manufacturing process is adopted, high-precision alignment of a plurality of patterned film layers can be realized by adopting exposure to recognize the same mark reference, the highest alignment precision can reach a hundred-nanometer level, and the alignment precision of the patterned film layer of a product processed by a conventional gluing equipment CCD recognition mode is about 20 microns; the method can effectively avoid the loss of luminous flux in the prism light transmission process caused by the deviation of a graphical film layer and the influence of stray light abnormity caused by the deviation on the imaging quality, can realize multi-fold prism processing, is applied to a mobile phone, can form an ultra-long light path in a narrow space in a folding manner, and has a wide application prospect. The ultra-high-magnification optical zoom and excellent image quality can be realized, and meanwhile, the relative lightness and thinness of a machine body are kept.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical element processing technology, and in particular to a high-magnification optical zoom "multi-fold" periscopic prism and a processing method thereof. BACKGROUND

[0002] With the continuous growth of the demand for mobile terminal thinness and high performance of photography, how to realize high magnification and high quality optical zoom in limited body space has become a key challenge. The traditional upright long-focus lens has been difficult to meet the demand due to the contradiction between the module height and the body thickness. Therefore, the industry generally adopts periscopic lens structure, which folds the optical path through a prism to build a longer focal length optical path in the lateral space, which is a "one reflection" or "three-fold" design. In order to further pursue the extreme focal length, a multiple reflection (such as "five reflections") optical path design scheme appears, aiming to more effectively compress the optical path and realize super long focal length.

[0003] In order to realize the five times refraction scheme, a multi-piece gluing process is usually adopted, and the alignment accuracy of the patterned film layer of the gluing layer is relatively high. The existing process scheme usually adopts a fixture for fixing alignment or a CCD of a gluing device for alignment, which has poor accuracy and is difficult to control. SUMMARY

[0004] To solve the above technical problems, the present application designs a high-magnification optical zoom "multi-fold" periscopic prism and a processing method thereof.

[0005] The present application adopts the following technical scheme: A processing method of a high-magnification optical zoom "multi-fold" periscopic prism, characterized by comprising the following steps: S1, selecting first, second, third and fourth optical lenses with the same refractive index for surface processing; S2, laser coding is performed on the second optical lens, so that there is one alignment mark on the left and right of the second optical lens; S3, processing of the patterned film layer of the second optical lens: First, the first surface of the second optical lens is coated, exposed, developed and black film coated, wherein the left and right marks of the substrate are recognized during exposure, so that the left and right marks on the photomask plate are aligned with the substrate marks, and then the product after coating is de-glued and ultrasonic cleaned, thereby completing the first surface patterned film layer processing of the second optical lens; The second surface of the second optical lens is coated, exposed, developed and black film coated, wherein the left and right film layer marks of the second optical lens are recognized during exposure for alignment, and then de-glued and ultrasonic cleaned, thereby completing the second surface patterned film layer processing of the second optical lens; S4, the second optical lens and the third optical lens are glued: the second optical lens and the third optical lens with two surface patterned film layers are glued by using glue with the same refractive index as the optical lens to form a first glue layer and are subjected to curing treatment; S5, third optical lens patterned film layer processing: the second optical lens and the third optical lens combination after gluing are subjected to gluing, exposure, development and black film coating processing, and the patterned film layer processing is carried out on the surface of the third optical lens of the combination, wherein the surface of the third optical lens is exposed while recognizing the left and right film layer marks of the second optical lens for alignment, and then the glue is removed and ultrasonic cleaning processing is carried out, to complete the third optical lens patterned film layer processing. S6, the second and third optical lens combination and the fourth or first optical lens are glued: the second and third optical lens combination and the fourth optical lens are glued by using glue with the same refractive index as the optical lens to form a second glue layer and are subjected to curing treatment; and then the second, third and fourth optical lens combination and the first optical lens are glued by using glue with the same refractive index as the optical lens to form a third glue layer and are subjected to curing treatment. S7, cutting processing: the large piece of optical lens after gluing is subjected to laser cutting or wire cutting processing, and is cut into a strip-shaped prism with a required shape, and during cutting, the left and right film layer alignment marks on the second optical lens are recognized by a CCD; S8, surface and shape processing is carried out on the strip-shaped prism, so that the shape and size of the product meet the design requirements.

[0006] As preferred, in the step S1, the surface processing of the first optical lens, the second optical lens, the third optical lens and the fourth optical lens is wire cutting, grinding and polishing processing, and the surface roughness Ra of the polished lens is less than 0.5 nm, the TTV is less than 3 um, and the PV is less than or equal to 25 um.

[0007] As preferred, the cross section of the patterned film layer is concave, and the inner frame edge of the patterned film layer is designed as a plurality of circular arc convexes uniformly arranged.

[0008] As preferred, in the step S3, the alignment accuracy of the left and right marks on the photomask plate and the substrate marks during exposure alignment is less than 2 um.

[0009] As preferred, in the step S3, the position accuracy of the two surface patterned film layers of the second optical lens is controlled within ±2 um.

[0010] As preferred, the curing treatment adopts UV curing treatment, the curing energy is 50000 mj / cm2, and after curing, the product is subjected to high temperature annealing treatment, the annealing temperature is 80-120℃, and the time is 0.5-5 hours.

[0011] As preferred, in the step S5, the position accuracy of the third optical lens and the patterning film layer of the second optical lens is controlled within ±2um.

[0012] As preferred, in the step S7, the position accuracy of the left and right film layer alignment mark on the second optical lens recognized by the CCD is within ±10um.

[0013] As preferred, in the step S8, the surface and profile processing of the strip-shaped prism includes grinding and polishing processing of the cut strip-shaped prism, milling, polishing, roughening processing of the strip-shaped prism, silk printing, film plating and slitting.

[0014] A high-magnification optical zoom "multi-fold" periscope prism includes a first optical lens, a second optical lens, a third optical lens and a fourth optical lens with the same refractive index, the second optical lens and the third optical lens are coated with a patterning film layer, and the first optical lens, the second optical lens, the third optical lens and the fourth optical lens are fixed as a whole by a glue layer.

[0015] The beneficial effects of the present application are: the present application adopts a semiconductor process, and multiple patterning film layers adopt exposure recognition of the same mark reference to achieve high-precision alignment, with a highest alignment accuracy of hundreds of nanometers, while the alignment accuracy of products processed by the existing CCD recognition method of the glue bonding equipment is about 20um, which can effectively avoid the loss of light flux in the prism light transmission process caused by the offset of the patterning film layer, and the influence of abnormal stray light caused by the offset on the imaging quality, and the process can realize multi-fold prism processing, and can "fold" a super-long light path in a narrow space on a mobile phone, and can realize super-high magnification optical zoom, excellent image quality, and at the same time, the body remains relatively thin. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural schematic diagram of a periscope prism in the present application; Figure 2 is a structural schematic diagram of a patterning film layer in the present application; In the figure: 1, first optical lens, 2, second optical lens, 3, third optical lens, 4, fourth optical lens, 5, first glue layer, 6, second glue layer, 7, third glue layer, 8, first patterning film layer, 9, second patterning film layer, 10, third patterning film layer. DETAILED DESCRIPTION

[0017] The technical solutions of the present application will be further described in detail below through specific embodiments and in combination with the drawings: Embodiment: as Figure 1As shown, a method for processing a high-magnification optical zoom "multi-fold" periscope prism, wherein the prism comprises: a first optical lens 1, a second optical lens 2, a third optical lens 3, a fourth optical lens 4, a first adhesive layer 5, a second adhesive layer 6, a third adhesive layer 7, a first patterned film layer 8, a second patterned film layer 9, and a third patterned film layer 10. The first patterned film layer 8 and the second patterned film layer 9 are arranged on both sides of the second optical lens 2, and the third patterned film layer 10 is arranged on the surface of the third optical lens 3. The second optical lens 2 and the third optical lens 3 are adhered by the first adhesive layer 5, the third optical lens 3 and the fourth optical lens 4 are adhered by the second adhesive layer 6, and the first optical lens 1 and the second optical lens 2 are adhered by the third adhesive layer 7. In this embodiment, the first optical lens, the second optical lens, the third optical lens, and the fourth optical lens are H-Bak7 with a refractive index of 1.568, and the patterned film layer is a black film with low reflection and low transmission. The film is coated on the surface of the second optical lens and the surface of the third optical lens. In order to suppress the concentrated diffraction phenomenon caused by sharp straight edges of the film layer (leading to ghosting and contrast reduction), the inner frame edges of the patterned film layer are designed as circular arc protrusions (as shown in Figure 2 When the light passes through the effective light transmission area, this design will disperse and offset the direction of the diffracted light, thereby converting the interference energy into weak and uniform background noise, effectively improving the image quality and transparency. The refractive index of all adhesive layers is 1.568.

[0018] The process for preparing the periscope prism is as follows: 1. Optical lens processing: Selecting appropriate optical glass or quartz as the first optical lens, the second optical lens, the third optical lens, and the fourth optical lens, and performing linear cutting, grinding, and polishing processing on the first, second, third, and fourth optical lenses. The surface roughness of the polished lenses is Ra<0.5 nm, the total thickness variation (TTV) is less than 3 um, and the peak-to-valley (PV) value is ≤25 um. 2. Laser coding on the second optical lens to form a mark on each side of the second optical lens. 3. Processing of the patterned film layer on the second optical lens: a. First, perform glue coating, exposure, development, and black film coating processing (first patterned film layer) on the first side of the second optical lens. During exposure, identify the marks on the left and right sides of the substrate to align the left and right marks on the photomask plate with the substrate marks with an alignment accuracy of <2 um. Then, perform glue removal and ultrasonic cleaning processing on the coated product to complete the patterned processing of the first side of the second optical lens. The film thickness is 1.3 um. b. The second surface of the second optical lens is coated, exposed, developed, and black film coated (second patterned film layer). The exposure is aligned with the left and right film layer marks of the second optical lens, and then the lens is de-glued and ultrasonically cleaned. The second surface of the second optical lens is patterned, and the position accuracy of the two surfaces of the second optical lens can be controlled within ±2um; 4. The second optical lens is glued with the third optical lens: the second optical lens and the third optical lens with two patterned film layers are glued (first glue layer) with glue of the same refractive index as the optical lens and are cured, the curing energy is 50000mj / cm2, and the product is annealed at high temperature after curing, the annealing temperature is 80~120℃, and the time is 0.5~5 hours. Through annealing, the residual reaction can be promoted in the area where UV irradiation is not enough or insufficient (such as shadow area, deep layer), there are still unreacted active groups (monomers, double bonds, etc.). Heating provides additional energy for these groups, enabling them to overcome the energy barrier and continue to react, thereby improving the final conversion rate, while releasing internal stress. UV curing is a rapid process, and the molecular chain is "frozen" and fixed in an instant, and a large amount of shrinkage stress and structural stress is accumulated inside. Heating enables the high molecular chain segment to have activity, relaxation and rearrangement, making the entire cross-linked network structure more uniform and stable; 5. Third optical lens patterned film layer processing: the second optical lens and the third optical lens assembly after gluing are coated, exposed, developed, coated, de-glued, and ultrasonically cleaned to complete the patterned film layer processing (third patterned film layer), which is processed on the surface of the third optical lens of the assembly. The third optical lens surface is aligned with the left and right film layer marks of the second optical lens during exposure. The position accuracy of the first surface pattern of the third optical lens and the second optical lens can be controlled within ±2um; 6. The second and third optical lens assembly is glued with the fourth or first optical lens: the second and third optical lens assembly is glued (second glue layer) with the fourth optical lens using glue of the same refractive index as the optical lens and is cured, the curing energy is 50000mj / cm2, and the product is annealed at high temperature after curing, the annealing temperature is 80~120℃, and the time is 0.5~5 hours. Then the second, third and fourth optical lens assembly is glued (third glue layer) with the first optical lens using glue of the same refractive index as the optical lens and is cured, the curing energy is 50000mj / cm2, and the product is annealed at high temperature after curing, the annealing temperature is 80~120℃, and the time is 0.5~5 hours; 7、Optical lens gluing processing: the patterned first optical lens and the second optical lens are glued by using the glue with the same refractive index as the optical lens and are cured, the curing energy is 50000 mj / cm2, after curing, the product is annealed at high temperature, the annealing temperature is 80~120℃, and the time is 0.5~5 hours; 8、Cutting processing: the glued large piece of optical lens is cut by laser cutting or wire cutting, and is cut into a strip-shaped prism with a required shape, during cutting, the CCD identifies the left and right film layer alignment mark on the second optical lens, and the position accuracy is ±10um; 9、Strip-shaped prism grinding and polishing processing: the cut strip-shaped prism is ground and polished to ensure the surface smoothness and flatness, the product surface roughness is less than 0.5nm, the PV is less than 0.3um, and the glue joint pit depth is ±10nm; 10、Strip-shaped prism shape processing: the strip-shaped prism is milled, polished, roughened and processed, so that the product shape and size meet the design requirements; 11、Screen printing: the strip-shaped prism is screen printed according to the design requirements, and after screen printing, a dust-free oven is used for heat curing, the baking temperature is 100~150℃, and the baking time is 30~180min.

[0019] 12、Coating: the long strip-shaped prism after screen printing is processed by optical film; 13、Slitting: the strip-shaped prism is slitted to cut into the final required prism.

[0020] The above-described embodiments are only a preferred scheme of the present application, and do not limit the present application in any form, and other variants and modifications are also possible without exceeding the technical scheme recorded in the claims.

Claims

1. A method for fabricating a high-magnification optical zoom "multi-fold" periscope prism, characterized in that, Includes the following steps: S1. Select the first, second, third, and fourth optical lenses with the same refractive index and perform surface processing. S2. Laser marking is performed on the second optical lens so that there is a alignment mark on each side of the second optical lens; S3, Patterning of the second optical lens: First, the first surface of the second optical lens is coated with adhesive, exposed, developed and coated with black film. During exposure, the left and right marks on the substrate are identified so that the left and right marks on the photomask are aligned with the substrate marks. Then, the coated product is subjected to adhesive removal and ultrasonic cleaning to complete the patterned film processing of the first surface of the second optical lens. The second surface of the second optical lens is coated with adhesive, exposed, developed and coated with black film. During exposure, the left and right film marks of the second optical lens are identified for alignment. Then, adhesive removal and ultrasonic cleaning are performed to complete the patterned film processing of the second surface of the second optical lens. S4. Bonding the second and third optical lenses: Using an adhesive with the same refractive index as the optical lenses, a first bonding layer is formed. The second and third optical lenses, which have completed the patterned film layers on both sides, are then bonded together and cured. S5. Patterned film processing of the third optical lens: The assembled second and third optical lenses after bonding are coated with adhesive, exposed, developed and coated with black film. The patterned film is processed on the surface of the third optical lens of the assembly. During the exposure of the surface of the third optical lens, the left and right film marks of the second optical lens are identified for alignment. Then, the adhesive is removed and ultrasonic cleaning is performed to complete the patterned film processing of the third optical lens. S6. Bonding the second and third optical lens assembly to the fourth or first optical lens: Using an adhesive with the same refractive index as the optical lens, a second adhesive layer is formed to bond the second and third optical lens assembly to the fourth optical lens and then cure it; then using an adhesive with the same refractive index as the optical lens, a third adhesive layer is formed to bond the second, third, and fourth optical lens assembly to the first optical lens and then cure it. S7. Cutting and processing: The large optical lens after bonding is laser-cut or wire-cut into strip prisms of the required shape. During cutting, the CCD identifies the alignment mark of the left and right film layers on the second optical lens. S8. Perform surface and shape processing on the strip prism to ensure that the product shape and size meet the design requirements.

2. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, In step S1, the surface processing of the first optical lens, the second optical lens, the third optical lens, and the fourth optical lens involves wire cutting, grinding, and polishing. The surface roughness of the polished lenses is Ra < 0.5 nm, TTV < 3 μm, and PV ≤ 25 μm.

3. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, The patterned membrane layer has a concave cross-section, and the inner frame edge of the patterned membrane layer is designed with multiple sets of arc-shaped protrusions evenly arranged.

4. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, In step S3, the alignment accuracy of the left and right marks on the photomask and the substrate mark during exposure alignment is <2µm.

5. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, In step S3, the positional accuracy of the patterned film layers on both sides of the second optical lens is controlled within ±2µm.

6. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, The curing process uses UV curing with a curing energy of 50,000 mj / cm2. After curing, the product undergoes high-temperature annealing at a temperature of 80~120℃ for 0.5~5 hours.

7. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, In step S5, the positional accuracy of the patterned film layer between the third optical lens and the second optical lens is controlled within ±2µm.

8. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, In step S7, the positional accuracy of the left and right film alignment marks on the second optical lens identified by the CCD is ±10µm.

9. The method for processing a high-magnification optical zoom "multi-fold" periscope prism according to claim 1, characterized in that, In step S8, the surface and shape processing of the strip prism includes grinding and polishing the cut strip prism, milling, polishing, roughening, screen printing, coating and slitting.

10. A periscope prism for achieving high-magnification optical zoom with multiple folds, characterized in that, It includes a first optical lens, a second optical lens, a third optical lens, and a fourth optical lens with the same refractive index. The second and third optical lenses are coated with a patterned film layer. The first, second, third, and fourth optical lenses are fixed together by an adhesive layer.

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