Collimation system for providing efficient parallel light rays
阅读说明：本技术 用于提供高效平行光线的准直系统 (Collimation system for providing efficient parallel light rays ) 是由 单延泉 张广军 卞海溢 于 2018-09-21 设计创作，主要内容包括：提供了一种准直系统,其包括至少一个玻璃基板(11、12)和存在于基板(11、12)的至少一个侧面上的至少一个聚合物透镜(1、2、3、4)。还提供了一种组件,其包括准直系统、至少一个光源(22)和至少一个光源基板(21)。又提供了一种制造准直系统的方法,以及准直系统的用途,特别是用于3D成像及感测、距离测量、深度测量、面部识别和/或物体识别。(A collimating system is provided comprising at least one glass substrate (11, 12) and at least one polymer lens (1, 2, 3, 4) present on at least one side of the substrate (11, 12). An assembly comprising a collimation system, at least one light source (22) and at least one light source substrate (21) is also provided. A method of manufacturing a collimation system is also provided, as well as uses of the collimation system, in particular for 3D imaging and sensing, distance measurement, depth measurement, face recognition and/or object recognition.)
1. A collimation system comprising at least one glass substrate (11, 12) and at least one polymer lens (1, 2, 3, 4) present on at least one side of the substrate (11, 12), wherein the collimation system has an aperture angle θ of less than 15 °, the ratio between the CTE of the polymer and the CTE of the glass is at most 40, and the difference between the thermal conductivity of the glass and the thermal conductivity of the polymer is at most 1.1W/(m K).
2. The collimating system of claim 1, wherein the total number of polymer lenses (1, 2, 3, 4) is at least 2.
3. The collimating system of claim 2, wherein the polymer lenses (1, 2, 3, 4) are distributed on the sides of the substrate (11, 12) based on a regular grid.
4. The collimation system as recited in any one of the preceding claims, wherein the polymer lenses (1, 2, 3, 4) are present on both sides of the substrate (11, 12).
5. The collimation system as recited in any of the preceding claims, wherein the polymer lens (1, 2, 3, 4) is composed of a polymer selected from the group consisting of epoxy and acrylic.
6. The collimation system of any of the preceding claims, wherein the glass is selected from the group consisting of silicate glass, borosilicate glass, aluminosilicate glass, and aluminoborosilicate glass.
7. The collimating system of any of the preceding claims, wherein the glass comprises components in the ranges indicated below in weight percent:
8. The collimating system of any of the preceding claims, wherein the glass comprises components in the ranges indicated below in weight percent:
9. The collimating system of any of claims 1 to 6, wherein the glass comprises a composition in weight percent within the range:
10. The collimation system of any of claims 1 to 8, wherein the glass comprises components in weight percent within the ranges indicated below:
11. the collimating system of any of claims 1 to 6, wherein the glass comprises a composition in weight percent within the range:
12. The collimation system as recited in any one of the preceding claims, wherein the collimation system comprises two glass substrates (11, 12).
13. The collimation system as recited in claim 12, wherein the two glass substrates (11, 12) are separated by a glass spacer (24).
14. The collimation system as recited in claim 13, wherein the glass spacer (24) has the same glass composition as the glass substrates (11, 12).
15. Collimation system as claimed in any one of the preceding claims, wherein the number of polymer lenses (1, 2, 3, 4) on both sides of the glass substrate (11, 12) is equal.
16. The collimation system as recited in claim 15, wherein the polymer lenses (1, 2, 3, 4) are positioned such that each lens (1, 2, 3, 4) on one side of the substrate (11, 12) has a corresponding lens (1, 2, 3, 4) on the other side of the substrate (11, 12).
17. The collimation system of any of the preceding claims, wherein the collimation system has an aperture angle θ of less than 10 °.
18. The collimation system of any of the preceding claims, wherein the glass has a thermal conductivity in a range of 0.7W/(m x K) to 1.4W/(m x K).
19. The collimation system of any of the preceding claims, wherein the polymer has a thermal conductivity in a range of 0.05W/(m x K) to 0.6W/(m x K).
20. The collimation system of any of the preceding claims, wherein a difference between a thermal conductivity of the glass and a thermal conductivity of the polymer is at most 1.0W/(m K).
21. The collimation system of any of the preceding claims, wherein the glass has a CTE of at most 15 ppm/K.
22. The collimation system of any of the preceding claims, wherein the CTE of the polymer is less than 200 ppm/K.
23. The collimation system as recited in any of the preceding claims, wherein a ratio between the CTE of the polymer and the CTE of the glass is at most 30.
24. The collimation system as recited in any one of the preceding claims, wherein a thickness of the glass substrate (11, 12) is in a range of 30 μ ι η to 1000 μ ι η.
25. The collimation system according to any of claims 8 to 19, wherein a thickness of the glass spacer (24) is in a range of 45 μ ι η to 1000 μ ι η.
26. The collimation system as recited in any one of the preceding claims, wherein the glass substrate (11, 12) and/or the glass spacer (24) is at 25mm2The local thickness variation LTV on the surface of (a) is less than 5 μm.
27. The collimation system according to any of the preceding claims, wherein a total thickness variation, TTV, of the glass substrates (11, 12) and/or the glass spacers (24) is less than 40 μ ι η.
28. The collimation system as defined in any one of the preceding claims, wherein the polymer of the polymer lens (1, 2, 3, 4) has a refractive index ndIn the range of 1.40 to 1.60.
29. The collimating system of any of the preceding claims, wherein the glass has a refractive index ndIn the range of 1.45 to 1.90.
30. The collimating system of any of the preceding claims, wherein the glass has a refractive index ndWith refractive index n of said polymerdThe difference between them is less than 0.5.
31. An assembly comprising a collimation system as claimed in any of the preceding claims, wherein the assembly further comprises at least one light source (22) and at least one light source substrate (21), wherein the light source (22) is located on one side of the light source substrate (21).
32. Assembly according to claim 31, wherein the light source substrate (21) is connected to one glass substrate (11, 12) of the collimation system by means of an adhesive (23).
33. The assembly of claim 31 or 32, wherein the light source (22) has a maximum emission wavelength in the range of 700nm to 1000 nm.
34. Assembly according to any one of claims 31 to 33, wherein the light source (22) is a laser light source (22) and wherein the light source substrate (21) is a laser light source substrate (21).
35. The assembly of any one of claims 31 to 34, wherein the light source (22) or the laser light source (22) is a Vertical Cavity Surface Emitting Laser (VCSEL) (22), and wherein the light source substrate (21) or the laser light source substrate (21) is a VCSEL substrate (21).
36. A method for manufacturing a collimation system as recited in any of claims 1 to 30, comprising the steps of:
a) providing at least one glass substrate (11, 12), and
b) at least one polymer lens (1, 2, 3, 4) is positioned on at least one side of the substrate.
37. The method according to claim 36, wherein the step of positioning the polymer lens (1, 2, 3, 4) on the substrate (11, 12) comprises the steps of:
b1) dripping liquid polymer resin onto the substrate (11, 12) at predetermined positions, and
b2) curing the polymer resin.
38. The method of claim 37, wherein the polymer resin is cured by UV light.
39. Use of the collimation system as recited in any one of claims 1 to 30, for 3D imaging and sensing, distance measurement, depth measurement, facial recognition, object recognition, animation, 3D modeling, 3D scanning, mobile payment, fingerprint sensors, augmented reality/virtual reality, and/or facial beautification.
Technical Field
The present invention relates to a collimation system. The present invention provides an efficient parallel-ray system, preferably for depth measurement or 3D imaging and sensing. The collimating system comprises at least one glass substrate and at least one polymer lens present on at least one side of the substrate. The invention also relates to an assembly comprising a collimation system, at least one light source and at least one light source substrate. The invention also relates to a method of manufacturing a collimation system and use of the collimation system, in particular for 3D imaging and sensing, distance measurement, depth measurement, face recognition, object recognition, animation, 3D modeling, 3D scanning, mobile payment, fingerprint sensors, augmented reality/virtual reality and/or facial beautification.
Background
The principle of the collimating lens is shown in fig. 1. In an ideal collimator, the light source is placed at the focal position S. The light image S' is at infinity. The light from the collimator is perfectly parallel. However, in practice, the light source cannot be located completely at the focal position because of the tolerances of each component, nor are the light rays from the collimator completely parallel. There is an aperture angle θ, which is the angle between the optical path and the optical axis, which may represent the degree of parallelism of the light rays produced by the collimating lens. The smaller the aperture angle θ, the more parallel the light rays produced by the collimating lens.
With the rapid development of consumer electronics, especially smart phones, more and more optical applications become the focus of attention. Collimating lenses are widely used to provide parallel light for applications such as 3D imaging and sensing, face recognition, and distance measurement. These lenses allow the user to control the field of view, acquisition efficiency, and spatial resolution of their settings, and to configure the illumination and acquisition angle for sampling.
Each component of the consumer electronic products requires low price, low power consumption, and small size to integrate it into current products. Wafer Level Packaging (WLP) is an ideal solution for handling complex Integrated Circuits (ICs) with a large number of inputs/outputs connected to the outside world. It may also be desirable to integrate various package-level circuit functions, such as microprocessing and graphics processing, Field Programmable Gate Array (FPGA) logic, dynamic and static memory, Radio Frequency (RF) and analog, and sensing and driving, etc., to be able to provide a complete system.
WLP processes are widely used today to manufacture front-facing cameras. The individual optical components are stacked together with spacers and sometimes filters in combination to form a single wafer-sized stack of thousands of optical devices. These Wafer Level Optics (WLO) are then stacked together with the image sensor to fabricate the camera. However, the key technology is to replicate UV polymers on transparent substrates.
The same method is used to fabricate the wafer level collimating lens. However, the usability of the resin and the substrate may be limited. To avoid material conflict, the lens and substrate of the conventional WLO are fabricated with the same material. To accommodate a given application, the collimating system should have good thermal conductivity, small size, and high efficiency.
While the previous disclosures have disclosed different structural components in the collimating lens or wafer level packaging methods or how to achieve an identified optical design, no disclosure is made as to the advantageous selection of component materials.
Although WO 2017/176213 a1 shows the WLP method, no combination of glass substrate and polymer lens is disclosed. Instead, a substrate made of a polymer is preferred. The glass may be present in the substrate in combination with the polymer in the form of a composite. However, it is suggested to use a wafer made of glass only as a carrier wafer, i.e. a wafer which differs from the actual substrate and does not have any polymer lenses.
WO 2017/039535 a1 shows a method of manufacturing a WLO, which discloses optical elements having a significantly different structure and based on a certain arrangement of two prisms. Furthermore, it does not even disclose a combination of a glass substrate and a polymer lens.
US 2017/0047362 a1 discloses: the thickness is very important in the entire optical path and spacers are used to adjust the total thickness. But does not disclose a combination of a glass substrate and a polymer lens.
However, highly parallel light has not been achieved to date, particularly in applications not associated with higher thermal loads, such as in applications using Vertical Cavity Surface Emitting Lasers (VCSELs) or edge emitting lasers as light sources. In particular, such lasers generate high temperatures in the case of high intensity and high contrast light. Thermal expansion effects cause the focal position to change, thereby causing the light rays from the lens to be insufficiently parallel to each other.
Disclosure of Invention
It is therefore an object of the present invention to overcome the disadvantages of the prior art. In particular, it is an object of the invention to provide a collimating system which is cheap but suitable for use in applications comprising VCSELs. It is another object of the invention to provide a collimating system that can provide efficient parallel light rays. The collimating system should have low temperature variation and low thermal distortion.
To achieve the above object, it has proved advantageous to combine a glass substrate with a polymer lens. Furthermore, it is particularly important to control the CTE and thermal conductivity of the glass and polymer relative to each other. In particular, the thermal conductivity should be selected so as to reduce temperature variations. In particular, the CTE should be chosen to reduce the effect of temperature variations on the optical performance so that the collimating system can provide highly parallel light rays even under such conditions.
The collimation system can be used for example for TOF (time of flight), structured light and stereo vision solutions.
This object is achieved by the subject matter of the patent claims. In particular, the object is achieved by a collimating system comprising at least one glass substrate and at least one polymer lens present on at least one side of the substrate, wherein the aperture angle θ of the collimating system is less than 15 °, the ratio between the CTE of the polymer (in the temperature range of 30 ℃ to 40 ℃) and the CTE of the glass (in the temperature range of 30 ℃ to 40 ℃) is at most 40, and wherein the difference between the thermal conductivity of the glass (at 89 ℃) and the thermal conductivity of the polymer (at 89 ℃) is at most 1.1W/(m · K).
The inventive collimating system comprises at least one glass substrate and at least one polymer lens present on at least one side of the substrate. Preferably, the polymer lens is directly adhered to the glass substrate. In other words, preferably, there is no adhesive layer or intermediate layer between the polymer lens and the glass substrate. However, in certain embodiments, one or more intervening layers may be present between the glass substrate and the polymer lens.
The polymeric lens comprises a polymeric material, preferably in an amount of at least 90 wt%, more preferably at least 95 wt%, more preferably at least 98 wt%, more preferably at least 99 wt%. Preferably, the polymer lens consists essentially of a polymer material. Therefore, other components are present as impurities at a content of not more than 0.1 wt% at most. In particular, polymer lenses are not composite materials containing other materials in amounts greater than 0.1 wt%.
Preferably, the glass substrate consists essentially of glass. Therefore, preferably, the other components are present as impurities at a content of not more than 0.1% at the most. In particular, the glass substrate is preferably not a composite material containing other materials than glass in an amount of more than 0.1 wt%. In some embodiments, a coating, particularly a Cr coating, may be applied to the glass substrate in areas of the substrate that do not have lenses. The coating helps to reduce stray light.
The aperture angle theta of the collimation system is less than 15 deg., preferably less than 10 deg., more preferably less than 5 deg., more preferably less than 2 deg., more preferably less than 1 deg., more preferably less than 0.5 deg., more preferably less than 0.1 deg., more preferably less than 0.01 deg..
The present invention shows a solution to the problems of the prior art based on a combination of a glass substrate and at least one polymer lens. An easily molded polymer lens is imprinted on a glass substrate. Glass is a material with a smaller CTE than polymeric materials. The temperature change of the glass is small. At the same time, glass has advantages in terms of deformation resistance compared to polymers. The glass has high hardness and good heat resistance.
However, the use of a combination of a glass substrate and a polymer lens for the collimating system is complicated. It is important that the material be chosen so as not to affect the focal length and light intensity. In particular, the collimating system should provide highly collimated light even in applications associated with elevated temperatures, including VCSELs. The inventors have found a solution to combine a glass substrate and a polymer lens in a collimating system. It is to be noted that the glass used for the glass substrate must be carefully selected. The following influencing factors have proven to be particularly important for obtaining a collimating system with excellent properties, in particular capable of producing highly parallel light rays.
As mentioned above, the substrate of the collimating system may be subjected to a significant amount of heat, particularly heat generated in applications including VCSELs. It is therefore advantageous if the substrate material has a higher thermal conductivity. From a material perspective, metals, while having the best thermal conductivity, are opaque. Glass is a good thermal conductivity material in the transparent group, its thermal conductivity is much better than that of polymers, and temperature variation can be reduced more effectively than polymers. Importantly, the collimation system of the present invention comprises a glass substrate. Furthermore, the collimation system of the invention may comprise one or more spacers, preferably glass spacers. Spacers, particularly glass spacers, are particularly useful in embodiments where the collimation system includes more than one glass substrate, such as two glass substrates. Preferably, the spacer (in particular the glass spacer) is located between the two glass substrates, such that the two glass substrates are spaced apart from each other and positioned at a distance from each other in the collimating system. Preferably, the spacer is a glass spacer. Preferably, the glass spacer and the glass substrate have the same glass composition. This is advantageous from an optical point of view and in order to minimize potential mechanical stresses in the collimation system, such as mechanical stresses caused by different expansion properties under thermal loading conditions. Thus, if glass properties or glass composition characteristics are described herein, they preferably refer to the glass in the glass substrate and the glass of the glass spacers optionally present. Further, the "polymer" in the present specification means a polymer of a polymer lens unless otherwise specified. Preferably, the material of the spacer is selected from the group consisting of glass, polymer, ceramic and metal. More preferably, the spacer is a glass spacer.
Preferably, the thermal conductivity of the glass is in the range of 0.7W/(m × K) to 1.4W/(m × K), more preferably 0.75W/(m × K) to 1.3W/(m × K), more preferably 0.85W/(m × K) to 1.25W/(m × K), more preferably 1.0W/(m × K) to 1.2W/(m × K) at 89 ℃.
Preferably, the thermal conductivity of the polymer is in the range of 0.05W/(m × K) to 0.6W/(m × K), more preferably 0.1W/(m × K) to 0.5W/(m × K), more preferably 0.15W/(m × K) to 0.4W/(m × K), more preferably 0.2W/(m × K) to 0.3W/(m × K) at 89 ℃.
Preferably, the thermal conductivity is according to ISO 22007-2: 2015 (E).
It is advantageous if the difference between the thermal conductivity of the glass and the thermal conductivity of the polymer is not very large, which is particularly advantageous for providing highly parallel light rays even with increased thermal loads. The difference between the thermal conductivity of the glass at 89 ℃ and the thermal conductivity of the polymer at 89 ℃ is at most 1.1W/(m × K), preferably at most 1.0W/(m × K), more preferably at most 0.95W/(m × K), more preferably at most 0.9W/(m × K), more preferably at most 0.85W/(m × K).
Furthermore, it is advantageous if the CTE of the glass (in the temperature range of 30 ℃ to 40 ℃) is rather low. Importantly, the smaller the CTE, the less the thickness and refractive index changes upon thermal shock. Thus, a smaller CTE is also associated with a smaller change in focal position upon thermal shock than a larger CTE. Preferably, the CTE of the glass (in the temperature range of 30 ℃ to 40 ℃) is at most 15ppm/K, more preferably at most 12ppm/K, more preferably at most 10 ppm/K.
It is advantageous if the CTE of the polymer (in the temperature range of 30 ℃ to 40 ℃) is not too large, so that large changes in material properties due to temperature changes are avoided. However, the CTE of generally suitable polymers is substantially much greater than the CTE of the glasses of the present invention. Preferably, the CTE of the polymer (in the temperature range of 30 ℃ to 40 ℃) is less than 200ppm/K, more preferably less than 150 ppm/K.
Preferably, the method is performed according to ISO 7991: 1987(E) to determine the CTE (in particular of glass). It can also be prepared according to ISO 11359-2: 1999(en) to determine CTE (especially of polymers). The skilled person is also aware of other suitable options for determining the CTE.
For other reasons, a lower CTE of the polymer is also advantageous. In fact, it is advantageous if the difference between the CTE of the polymer and the CTE of the glass is small. In other words, the ratio between the CTE of the polymer and the CTE of the glass should not exceed a certain value, so that stress caused by temperature change after the assembly of the glass substrate and the polymer lens can be reduced. Notably, higher stresses increase the rate of cracking during subsequent cutting. Furthermore, even with increased thermal load, a small difference between the CTE of the polymer and the CTE of the glass is beneficial for providing highly parallel light rays. The ratio between the CTE of the polymer (in the temperature range of 30 ℃ to 40 ℃) and the CTE of the glass (in the temperature range of 30 ℃ to 40 ℃) is at most 40, preferably at most 30, more preferably at most 25, more preferably at most 20, more preferably at most 15, more preferably at most 10.
The size of the collimation system as a whole is very important, especially in consumer electronics. The market trend is that thinner is better. It is noteworthy that glass, while providing sufficient strength, also serves as a good material for thinner substrates. Preferably, the thickness of the glass substrate is in the range of 30 μm to 1000 μm, more preferably 50 μm to 800 μm, more preferably 70 μm to 700 μm, more preferably 100 μm to 600 μm. In some preferred embodiments, the thickness of the glass substrate is at most 400 μm, more preferably at most 300 μm, more preferably at most 250 μm, more preferably at most 200 μm.
Preferably, the thickness of the spacer (especially glass spacer) is in the range of 45 μm to 1000 μm, more preferably 75 μm to 1000 μm, more preferably 100 μm to 1000 μm. Preferably, the thickness of the spacers (in particular the glass spacers) is chosen such that the glass substrates are at a distance from each other, thereby avoiding direct physical contact between the polymer lenses, which may be present on one side of the substrates, and the polymer lenses, which may be present on another substrate, wherein the two substrates are opposite to each other.
If the glass has small thickness variations, in particular small Local Thickness Variations (LTV) and/or small total thickness variations (T)TV), it is also advantageous. Variations in the thickness of the glass substrate and/or spacers (particularly glass spacers) also affect the focal position, such that larger variations are associated with larger aperture angles θ, and thus less parallel rays. The LTV is the difference between the highest and lowest points within one side of the substrate and/or spacer surface. Thus, LTV describes local thickness fluctuations as a surface quality feature on a surface. Preferably, at 25mm2The LTV of the glass substrate and/or the spacers (in particular glass spacers) on the surface is less than 5 μm, more preferably less than 2 μm.
TTV (total thickness variation) is understood to be the difference between the highest and lowest protrusions on the surface of the glass substrate and/or spacer with respect to the side. Thus, TTV describes the thickness variation inside the glass substrate and/or spacer. Preferably, the TTV of the glass substrate and/or the spacer (in particular the glass spacer) is less than 40 μm, more preferably less than 30 μm, more preferably less than 20 μm, more preferably less than 16 μm, more preferably less than 14 μm, more preferably less than 12 μm, more preferably less than 10 μm, more preferably less than 8 μm, more preferably less than 6 μm, more preferably less than 4 μm. Preferably, the TTV is determined from SEMI MF 1530 GBIR.
Another important aspect is the refractive index nd. Albeit with a larger refractive index ndThe overall package size can be reduced, but it is difficult to obtain a high refractive index n for polymer lens materialsd. Preferably, the refractive index n of the polymer lensdIn the range of 1.40 to 1.60, more preferably 1.42 to 1.58, more preferably 1.44 to 1.56, more preferably 1.45 to 1.55, more preferably 1.46 to 1.54.
Preferably, the refractive index n of the glassdIn the range of 1.45 to 1.90, more preferably 1.46 to 1.80, more preferably 1.47 to 1.70, more preferably 1.48 to 1.65, more preferably 1.49 to 1.60, more preferably 1.50 to 1.54.
Particularly good optical properties can be obtained by small differences between the refractive indices of the glass and the polymer material. Otherwise, light loss at the boundary between the two materials can impair light intensity, which can affect imaging quality in applications. In addition, small differences are also advantageous for obtaining highly parallel light rays. Preferably, the folding of the glassIndex of refraction ndRefractive index n with polymerdThe difference therebetween is less than 0.5, more preferably less than 0.4, more preferably less than 0.3, more preferably less than 0.2, more preferably less than 0.1, more preferably less than 0.06, more preferably less than 0.05, more preferably less than 0.04, more preferably less than 0.03, more preferably less than 0.02, more preferably less than 0.01.
Another important aspect is the strength of the bond between the glass substrate and the polymer lens. In particular, the polymer lens should adhere well to the glass substrate during the lifetime of the collimating system. The bonding strength can be increased, for example, by selecting advantageous glass surface properties, in particular those which increase the wettability of the glass by means of polymers. Preferably, the glass of the invention has a surface roughness Ra of less than 1 nm.
Preferably, a contact angle of less than 25 ° is obtained on the clean surface between the glass substrate and the polymer lens, in particular between the two.
According to certain aspects of the present invention, the glass of the glass substrate may be cut, diced, coated, chemically tempered, etched and/or structured.
Preferably, the glass substrate and the polymer lens of the present invention have a transmittance of more than 90%, particularly in the wavelength range of 380nm to 1200nm, thereby obtaining particularly good optical properties. The term "transmittance" as used in this specification refers to the total transmittance, further refers to the percentage of light intensity behind the glass substrate and/or polymer lens to the originally applied light intensity.
Preferably, the glass is selected from the group consisting of silicate glass (in particular soda lime glass), borosilicate glass, aluminosilicate glass and aluminoborosilicate glass. Borosilicate glass, aluminosilicate glass and soda-lime glass are particularly preferred.
In a preferred embodiment of the invention, the glass preferably comprises components in the ranges indicated below, in percentages by weight:
components
Weight percent of
SiO2
63-85
Al2O3
0-10
B2O3
5-20
Li2O+Na2O+K2O
2-14
MgO+CaO+SrO+BaO+ZnO
0-12
TiO2+ZrO2
0-5
P2O5
0-2
In a preferred embodiment of the invention, the glass preferably comprises components in the ranges indicated below, in percentages by weight:
in a preferred embodiment of the invention, the glass preferably comprises components in the ranges indicated below, in percentages by weight:
components
Weight percent of
SiO2
58-65
Al2O3
14-25
B2O3
6-10.5
MgO+CaO+SrO+BaO+ZnO
8-18
ZnO
0-2
In a preferred embodiment of the invention, the glass preferably comprises components in the ranges indicated below, in percentages by weight:
in a preferred embodiment of the invention, the glass preferably comprises components in the ranges indicated below, in percentages by weight:
components
Weight percent of
SiO2
52-66
B2O3
0-8
Al2O3
15-25
MgO+CaO+SrO+BaO+ZnO
0-6
ZrO2
0-2.5
Li2O+Na2O+K2O
4-30
TiO2+CeO2
0-2.5
In the above glass composition, As is used in an amount of 0 to 2 wt%2O3、Sb2O3、SnO2、SO3Cl, F and/or CeO2As a refining agent.
Preferably, the polymer of the polymer lens is a resin, which is preferably selected from the group consisting of epoxy resins and acrylic resins, wherein epoxy resins are particularly preferred. Particularly preferred polymers are epoxy resins selected from the group consisting of DELO KATIOBOND OM614, DELO KATIOBOND AD VE 18499 and DELO KATIOBOND OM VE 110021. Such epoxy resins are supplied by DELO industrial adhesives (wendah, germany).
As mentioned above, the present invention relates to a collimating system comprising at least one glass substrate and at least one polymer lens present on at least one side of the substrate.
The glass substrate of the present invention preferably has the form of a sheet or a disk or a plate. In other words, the length and width of the substrate are preferably much greater than its thickness. Or in the case of a circular base region, a diameter much greater than the thickness of the substrate. Preferably, the term "substantially larger" means that the length, width or diameter of the substrate is at least 5 times, more preferably at least 10 times, more preferably at least 20 times, more preferably at least 30 times, more preferably at least 40 times, more preferably at least 50 times greater than its thickness. The sheet-like substrate has two major surfaces which may be referred to as substrate "sides". Thus, the substrate has two sides.
Preferably, the polymer lenses are located on both sides of the substrate. More preferably, the number of polymer lenses on each of the two sides of the glass substrate is equal. Preferably, the polymer lenses are positioned such that each lens on one side of the substrate has a corresponding lens on the other side of the substrate. Preferably, the corresponding lenses are substantially aligned with each other. In other words, the corresponding lenses are preferably lenses having the same optical axis on opposite sides of the substrate, or lenses on opposite sides of the substrate, the optical axes of which are deviated from each other by at most 10%, more preferably 5%, more preferably 2%, more preferably 1% of the diameter of the lens on the substrate surface.
The total number of polymer lenses in the collimating system is at least 1, preferably at least 2, more preferably at least 3, more preferably at least 4, more preferably at least 6. Preferably, the total number of polymer lenses on one side of the substrate is at least 1, preferably at least 2, more preferably at least 3, more preferably at least 4, more preferably at least 6, more preferably at least 10, more preferably at least 20, more preferably at least 30, more preferably at least 40, more preferably at least 50. Preferably, the total number of polymeric lenses on each of the two sides of the substrate is at least 1, preferably at least 2, more preferably at least 3, more preferably at least 4, more preferably at least 6, more preferably at least 10, more preferably at least 20, more preferably at least 30, more preferably at least 40, more preferably at least 50.
Preferably, the collimation system comprises two glass substrates. Preferably, the two glass substrates are separated by a spacer (in particular a glass spacer). Preferably, the glass spacer and the glass substrate have the same glass composition. Preferably, the spacer (in particular the glass spacer) has a plurality of holes at the location of the polymer lenses on the glass substrate separated by the spacer (in particular the glass spacer). Such holes are advantageous because physical contact between the spacer, particularly a glass spacer, and the polymer lens is avoided.
In some embodiments, the collimating system may further comprise at least one light guide, which is advantageous for changing the light path.
The invention also relates to an assembly; the assembly comprises the collimation system of the invention, and further comprises at least one light source and at least one light source substrate. The light source is preferably a laser light source, more preferably a Vertical Cavity Surface Emitting Laser (VCSEL). The light source substrate is preferably a laser light source substrate, and more preferably a VCSEL substrate. Wherein the light source, preferably the laser light source, more preferably the VCSEL, is located on one side of the light source substrate, preferably the laser light source substrate, more preferably the VCSEL substrate. Preferably, the laser light source substrate, preferably the laser light source substrate, more preferably the VCSEL substrate, is connected with one of the glass substrates of the collimating system via an adhesive. The assembly may also be referred to as an optical assembly. Preferably, the maximum emission wavelength of the light source, preferably the laser light source, more preferably the VCSEL, is in the range of 700nm to 1200nm, more preferably 700nm to 1000nm, more preferably 800nm to 1000nm, more preferably 825nm to 950 nm. Particularly preferred light sources, preferably laser light sources, more preferably VCSELs, have a maximum emission wavelength in the range from 840nm to 860nm or 930nm to 950 nm. Light sources, preferably laser light sources, more preferably VCSELs, with a maximum emission wavelength in the range of 840nm to 860nm are useful for face/object recognition, especially face or person detection. A light source with a maximum emission wavelength in the range of 930nm to 950nm, preferably a laser light source, more preferably a VCSEL, may be used to reduce the influence of ambient light.
The invention also relates to a method for manufacturing a collimation system according to the invention, comprising the steps of:
a) providing at least one glass substrate, and
b) at least one polymer lens is positioned on at least one side of the substrate.
Preferably, the step of positioning the polymer lens on the substrate comprises the steps of:
b1) dropping a liquid polymer resin onto the substrate at a predetermined position, and
b2) the polymer resin is cured.
Preferably, the polymer resin is cured by UV light or thermal methods. Preferably, the polymer resin is cured by UV light.
The invention also relates to the use of the collimation system thereof in 3D imaging and sensing, distance measurement, depth measurement, face recognition, object recognition, animation, 3D modeling, 3D scanning, mobile payment, fingerprint sensors, augmented reality/virtual reality and/or facial cosmetology.
Drawings
Fig. 1 schematically illustrates the principle of the collimator lens 102 (as indicated by the vertical up and down arrows). At the focal position S of the collimator lens 102 there is a light emitter 101 (shown as a circle). The position of the light image is indicated by S'. The aperture angle θ represents the angle between the light path (as indicated by the arrow) and the optical axis (as indicated by the horizontal dashed line), which may represent the parallelism of the light produced by the collimating lens 102.
Fig. 2 schematically shows a top view of the microlens array 201. A plurality of polymer lenses 203 are located on a circular glass substrate 202.
Figure 3 schematically shows a partial cross-section of an assembly comprising a collimation system of the invention. As shown in fig. 2, the collimating system may include a plurality of polymer lenses. For better understanding, however, fig. 3 shows only one such polymer lens 1. The polymer lens 1 is located on the upper side of the glass substrate 11. The lower side of the glass substrate 11 is connected to the upper side of a VCSEL (vertical cavity surface emitting laser) substrate 21 via an adhesive 23. The assembly further comprises a VCSEL22 on the upper side of the VCSEL substrate 21.
Figure 4 schematically shows a partial cross-section of an assembly comprising a collimation system of the invention. The collimation system of fig. 4 differs from the collimation system of fig. 3 in that the collimation system of fig. 4 comprises one polymer lens 2 on the upper side of the glass substrate 11 and another polymer lens 1 on the lower side of the glass substrate 11. The polymer lens 2 and the polymer lens 1 are aligned with each other and have the same optical axis (not shown). The lower side of the glass substrate 11 is connected to the upper side of the VCSEL substrate 21 via an adhesive 23. The assembly further comprises a VCSEL22 on the upper side of the VCSEL substrate 21.
Figure 5 schematically shows a partial cross-section of an assembly comprising a collimation system of the invention. The collimation system of fig. 5 comprises two glass substrates 11, 12. The polymer lens 4 is located on the upper side of the upper glass substrate 12. The polymer lens 3 is located on the underside of the upper glass substrate 12. The polymer lens 2 is located on the upper side of the lower glass substrate 11. The polymer lens 1 is located on the lower side of the lower glass substrate 11. The polymer lenses are aligned with each other and have the same optical axis (not shown). The lower side of the lower glass substrate 11 is connected to the upper side of the VCSEL substrate 21 via an adhesive 23. The assembly also includes a VCSEL22 on the upper side of the VCSEL substrate 21. The upper glass substrate 12 and the lower glass substrate 11 are separated by a spacer 24 (particularly, a glass spacer 24). The spacer 24, in particular the glass spacer 24, comprises a recess for accommodating the polymer lenses 3 and 2. The thickness of the spacer 24, in particular the glass spacer 24, is chosen such that the glass substrates 12 and 11 are spaced apart from each other by a distance such that direct physical contact between the polymer lenses 3 and 2 is avoided. As shown in fig. 5, lenses 3 and 2 have matching curved shapes, which may help reduce chromatic aberrations.
Detailed Description
Example 1
The collimating module as shown in fig. 3 was simulated by selecting the following materials:
a glass substrate (glass 1) having the following composition:
polymer lens material: DELO OM 614.
The working temperature is 25 ℃ to 60 ℃.
Wavelength of incident light: 940 nm.
Original lens size: the chord length is 2mm, and the height is 0.2 mm.
Simulation results are as follows:
the aperture angle θ is 0.00156 °.
Thus, a very low aperture angle is achieved by combining glass 1 and the OM614 polymer lens.
Example 2
The collimating module as shown in fig. 3 was simulated by selecting the following materials:
a glass substrate (glass 2) having the following composition:
components
Weight percent of
SiO2
61
B2O3
11
Al2O3
18
MgO
3
CaO
4
BaO
3
Polymer lens material: DELO OM 614.
The working temperature is 25 ℃ to 60 ℃.
Wavelength of incident light: 940 nm.
Original lens size: the chord length is 2mm, and the height is 0.2 mm.
Simulation results are as follows:
the aperture angle θ is 0.00164 °.
Thus, a very low aperture angle is achieved by combining glass 2 and the OM614 polymer lens.
Example 3
The collimating module as shown in fig. 3 was simulated by selecting the following materials:
a glass substrate (glass 3) having the following composition:
components
Weight percent of
SiO2
70
B2O3
0.1
Na2O
10
K2O
8
ZnO
4
CaO
6
BaO
2.5
Polymer lens material: DELO OM 614.
The working temperature is 25 ℃ to 60 ℃.
Wavelength of incident light: 940 nm.
Original lens size: the chord length is 2mm, and the height is 0.2 mm.
Simulation results are as follows:
the aperture angle θ is 0.00257 °.
Thus, a very low aperture angle is achieved by combining glass 3 and the OM614 polymer lens.
List of reference numerals
1 Polymer lens
2 Polymer lens
3 Polymer lens
4 Polymer lens
11 glass substrate
12 glass substrate
21 light source substrate, in particular VCSEL (vertical cavity surface emitting laser) substrate
22 light source, in particular VCSEL
23 adhesive
24 spacer, in particular glass spacer
101 light emitter
102 collimating lens
201 microlens array
202 glass substrate
203 Polymer lens
- 上一篇：一种医用注射器针头装配设备
- 下一篇：标记装置、标记方法、偏振片制造方法以及偏振片