Biometric optical components and devices

Abstract

The present invention discloses a biometric identification optical component, which includes a flat glass group, a lens group including a brightness aperture, a filter and a photosensitive chip in order from the object side, wherein the flat glass group includes a first flat glass and satisfies the following conditional formula: TTL / f<10.3; D / f<4.2; wherein TTL is the distance between the object side of the first flat glass and the photosensitive surface of the photosensitive chip, f is the focal length of the lens group, and D is the diagonal length of the photosensitive surface of the photosensitive chip. The biometric identification optical component provided by the present invention has the characteristics of good performance, compact structure and small size. The present invention also discloses a biometric identification optical device.

Description

Technical Field

[0001] The present invention relates to the field of biometric identification optical technology, and in particular to a biometric identification optical component and device. Background Art

[0002] With the popularization of mobile Internet and the coming of the Internet of Things, people have more and more demands for health, safety, and new experiences, and their requirements are getting higher and higher. For example, the rise of full-screen displays in the mobile field, because capacitive fingerprint recognition occupies the space of the screen, is not conducive to user experience, forcing the fingerprint recognition area to move from the top of the screen to under the screen. Optical recognition under the screen has also become a trend; for example, various wearable applications require imaging of the blood vessels of organisms to interpret various characteristics of organisms such as the shape of veins, changes in blood flow velocity, changes in heart rate, various blood parameters, etc.; for example, the recognition of biological iris textures, such as spots, stripes, filaments, crowns, crypts and eye lesions.

[0003] However, how to make the under-screen optical fingerprint recognition system thinner and more integrated is a technical difficulty of under-screen fingerprint recognition. At the same time, gradually shrinking the chip will help reduce the cost of the chip in the entire system. How to obtain high-quality images in a smaller space is even more technically difficult. The lightweight requirements of various wearable products also require reduced power consumption and miniaturization of components to improve user experience. The miniaturization of the bio-optical recognition system is conducive to the miniaturization of bio-vascular imaging recognition devices and bio-iris recognition devices, transforming them from expensive large-scale equipment into mass consumer products. Summary of the invention

[0004] The object of the present invention is to provide a biometric identification optical component which has the characteristics of compact structure and small size.

[0005] The technical solution adopted by the biometric optical component disclosed in the present invention is:

[0006] A biometric identification optical component includes, from the object side, a flat glass group, a lens group including a brightness aperture, a filter, and a photosensitive chip, wherein the flat glass group includes a first flat glass and satisfies the following conditional formula:

[0007] TTL / f<10.3;

[0008] D / f<4.2;

[0009] Wherein, TTL is the distance between the object side of the first flat glass and the photosensitive surface of the photosensitive chip, f is the focal length of the lens group, and D is the diagonal length of the photosensitive surface of the photosensitive chip.

[0010] As a preferred solution, the flat glass group further includes a second flat glass, and the second flat glass is arranged between the first flat glass and the lens group including the brightness aperture.

[0011] As a preferred solution, the lens group including a brightness aperture includes a brightness aperture and a first lens.

[0012] As a preferred solution, the lens group including the brightness aperture further includes a second lens.

[0013] As a preferred solution, the brightness aperture is arranged between the first lens and the flat glass group, and the first lens is arranged between the brightness aperture and the second lens.

[0014] As a preferred solution, the first lens is arranged between the brightness aperture and the flat glass group, and the brightness aperture is arranged between the first lens and the second lens.

[0015] As a preferred solution, the first lens is a lens with an aspherical surface.

[0016] As a preferred solution, the second lens is a plastic lens.

[0017] The beneficial effects of a biometric optical component disclosed in the present invention are: TTL / f<10.3 ensures a compact and flat structure, D / f<4.2, which is conducive to miniaturization of the chip size, and the lens group images the biometric features in front of the first flat glass onto the photosensitive surface of the chip to obtain the best imaging effect, which can effectively solve the interference of the under-screen structure on the imaging quality and is convenient for application on portable mobile devices.

[0018] The present invention also discloses a biometric optical device, which can be used for under-screen fingerprint recognition, blood vessel imaging recognition and iris recognition. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the first embodiment of the biometric identification optical component of the present invention;

[0020] Figure 2 is an MTF curve performance diagram of the first embodiment of the biometric optical component of the present invention;

[0021] Figure 3 This is a schematic diagram of periodic fringe resolution and recognition in Embodiment 1 of the biometric identification optical component of the present invention;

[0022] Figure 4 is a schematic diagram of the structure of the second embodiment of the biometric optical component of the present invention;

[0023] Figure 5 is an MTF curve performance diagram of the second embodiment of the biometric optical component of the present invention;

[0024] Figure 6 This is a schematic diagram of periodic fringe resolution and recognition in Embodiment 2 of the biometric identification optical component of the present invention;

[0025] Figure 7is a schematic diagram of the structure of the third embodiment of the biometric optical component of the present invention;

[0026] Figure 8 is an MTF curve performance diagram of the third embodiment of the biometric optical component of the present invention;

[0027] Fig. 9 This is a schematic diagram of periodic fringe resolution and recognition in Embodiment 3 of the biometric identification optical component of the present invention;

[0028] Fig.10 is a schematic structural diagram of a fourth embodiment of a biometric identification optical component of the present invention;

[0029] Fig.11 is an MTF curve performance diagram of the fourth embodiment of the biometric optical component of the present invention;

[0030] Fig.12 This is a schematic diagram of periodic fringe resolution and recognition in Embodiment 4 of the biometric identification optical component of the present invention;

[0031] Fig.13 is a schematic diagram of the structure of a fifth embodiment of a biometric identification optical component of the present invention;

[0032] Fig.14 is an MTF curve performance diagram of the fifth embodiment of the biometric optical component of the present invention;

[0033] Fig.15 It is a schematic diagram of periodic fringe resolution and recognition of Embodiment 5 of the biometric identification optical component of the present invention. DETAILED DESCRIPTION

[0034] A biometric identification optical component includes, from the object side, a flat glass group, a lens group including a brightness aperture, a filter, and a photosensitive chip, wherein the flat glass group includes a first flat glass, and the biometric identification optical component satisfies the following conditional formula:

[0035] TTL / f<10.3; D / f<4.2;

[0036] Among them, TTL is the distance between the front surface of the first flat glass and the photosensitive surface of the photosensitive chip, f is the focal length of the biometric optical component, and D is the diagonal length of the photosensitive surface of the photosensitive chip.

[0037] If TTL / f exceeds its upper limit, it is not conducive to compact structure. If D / f exceeds its upper limit, it is not conducive to miniaturization of photosensitive chip size. The brightness aperture plays a role in adjusting the amount of incoming light. The lens group containing the brightness aperture images the biometric features in front of the first flat glass onto the photosensitive surface of the photosensitive chip. The position of the lens group containing the brightness aperture is adjusted forward and backward to obtain the best imaging effect. Combined with the processing circuit, the data processing algorithm can obtain useful biometric information.

[0038] The brightness aperture plays a role in adjusting the amount of incoming light. Its size is related to the performance of the lens group containing the brightness aperture and the size of the photosensitive chip unit. Setting a suitable brightness aperture has a certain influence on the best recognition effect.

[0039] As a preferred solution, the flat glass group includes a second flat glass, which can be printed or attached to the brightness aperture on its rear surface to fix the aperture position and protect the brightness aperture. Its thickness can be adjusted according to the external space of the component, and the overall structure length can be fine-tuned to meet different application requirements.

[0040] As a preferred solution, the lens group containing the brightness aperture contains at least one lens, and containing two or more lenses can also help improve the performance;

[0041] As a preferred solution, the lens group containing a brightness aperture includes a brightness aperture, a first lens and a second lens. The brightness aperture is arranged between the first lens and the second lens to reduce the difficulty of manufacturing the brightness aperture, while improving the sensitivity of the component to asymmetric aberrations. For example, when the brightness aperture is increased, the effect is more advantageous.

[0042] The lens group containing the brightness aperture contains a lens with at least one aspherical surface. The aspherical surface can effectively improve the aberration of peripheral light, better correct spherical aberration and peripheral aberration, and obtain better aberration performance. At the same time, it is beneficial to adjust the edge thickness of the lens and facilitate processing and production. The lens group can contain multiple aspherical surfaces or all of them are aspherical surfaces.

[0043] As a preferred solution, the lens group containing the brightness aperture contains at least one plastic lens, which is conducive to batch injection molding production and reduces costs. It can contain multiple plastic lenses or all plastic lenses.

[0044] The biometric optical component disclosed in the present invention can effectively solve the interference of the under-screen structure on the imaging quality and meet the under-screen fingerprint recognition needs; it can meet the needs of biometrics and has the characteristics of good performance, compact structure, miniaturization of photosensitive chips and easy application on mobile portable devices.

[0045] In order to achieve the effects and purposes of the present invention, in the implementation scheme, the following aspheric formula is used:

[0046]

[0047] Among them, Z represents the vector height of the aspheric surface along the optical axis, y represents the distance of the aspheric surface along the direction perpendicular to the optical axis, c represents the central curvature, which is the inverse of the radius, k represents the cone coefficient or the quadratic constant, and A2-A16 represent the 2nd to 16th aspheric coefficients respectively.

[0048] The present invention will be further described and illustrated below in conjunction with specific embodiments and accompanying drawings:

[0049] Example 1

[0050] Please refer to Figure 1 A biometric optical component includes a first flat glass 10, a brightness aperture 30, a first lens 20 with positive focal length, a filter 40 and a photosensitive chip 50. The first flat glass 10 is a protective glass for the screen, with a thickness of 1.2 mm. The filter 40 cuts off unnecessary long-wavelength light to reduce the interference of long-wavelength light. Both sides of the first lens 20 are aspherical surfaces, and the photosensitive chip 50 has a convex aspherical surface. The aspherical surface can comprehensively improve the effect of the product. This embodiment can achieve a TTL of less than 4 mm, a recognition area greater than 5 mm*5 mm, and a diagonal size of the photosensitive chip 50 can be less than 1.2 mm, achieving a better cost effect on the basis of satisfying the recognition effect.

[0051] The following are the relevant parameters about the component:

[0052]

[0053] Component focal length f = 0.55

[0054] Fno=2.40

[0055] TTL=3.97

[0056] D=1.24

[0057] TTL / f=7.22

[0058] D / f=2.25

[0059]

[0060] Example 2

[0061] Please refer to Figure 2A biometric optical component includes a first flat glass 10, a second flat glass 11, a brightness aperture 30, a first lens 20 with positive focal power, a filter 40 and a photosensitive chip 50. The first flat glass 10 is a protective glass for the screen, with a thickness of 1.6 mm. The second flat glass 11 has a thickness of 0.3 mm. Its thickness can be adjusted according to the external space of the component, and the overall structure length can be fine-tuned to meet different application requirements. At the same time, the image side of the second flat glass 11 can be printed or attached to the brightness aperture 30. The filter 40 cuts off unnecessary long-wave light to reduce the interference of long-wave light. Both sides of the first lens 20 are aspherical surfaces, and one side of the photosensitive chip 50 is a convex aspherical surface. The aspherical surface can comprehensively improve the effect of the product. This embodiment can achieve a TTL of less than 4.2 mm, a recognition area greater than 4 mm*4 mm, and a chip diagonal size of less than 1.2 mm. On the basis of meeting the recognition effect, it has the advantages of simple assembly, compact structure and comprehensive cost advantages.

[0062] The following are the relevant parameters about the component:

[0063]

[0064] Component focal length f = 0.57

[0065] Fno=2.60

[0066] TTL=4.18

[0067] D=1.13

[0068] TTL / f=7.33

[0069] D / f=1.98

[0070]

[0071]

[0072] Example 3

[0073] Please refer to Figure 7A biometric optical component includes, from the object side, a first flat glass 10, a brightness aperture 30, a first lens 21, a second lens 22, a filter 40 and a photosensitive chip 50. The first flat glass 10 is a protective glass for the screen, with a thickness of 2.0 mm. The filter 40 cuts off unnecessary long-wave light to reduce the interference of long-wave light. Both sides of the first lens 21 are aspherical surfaces, and the object side of the first lens 21 is an aspherical surface with an inflection point. Both sides of the second lens 22 are aspherical surfaces, and the image side is convex. The use of aspherical surfaces can achieve comprehensive performance balance. This embodiment can achieve TTL less than 5.0 mm, the recognition area is greater than 6.0 mm*6.0 mm, and the diagonal size of the photosensitive chip can be less than 1.4 mm, achieving better performance and compact structure.

[0074] The following are the detailed parameters about the component:

[0075]

[0076] Component focal length f = 0.64

[0077] Fno=2.8

[0078] TTL=4.11

[0079] D=1.48

[0080] TTL / f=6.42

[0081] D / f=2.31

[0082]

[0083] Example 4

[0084] Please refer to Fig.10 A biometric optical component includes, from the object side, a first flat glass 10, a first lens 21, a brightness aperture 30, a second lens 22, a filter 40 and a photosensitive chip 50. The first flat glass 10 is a protective glass for the screen, with a thickness of 2.0 mm. The filter 40 cuts off unnecessary long-wave light to reduce the interference of long-wave light. Both sides of the first lens 21 are aspherical surfaces, and the object side of the first lens 20 is an aspherical surface with an inflection point. Both sides of the second lens 22 are aspherical surfaces, and the image side is convex. The use of aspherical surfaces can achieve comprehensive performance balance. This embodiment can achieve TTL less than 5.0 mm, the recognition area is greater than 6.0 mm*6.0 mm, and the chip diagonal size D can be less than 1.4 mm, achieving better performance and compact structure.

[0085] The following are the detailed parameters about the component:

[0086]

[0087]

[0088] Component focal length f = 0.48

[0089] Fno=2.35

[0090] TTL=4.69

[0091] D=1.33

[0092] TTL / f=9.77

[0093] D / f=2.77

[0094]

[0095] Example 5

[0096] Please refer to Fig.13 A biometric optical component includes, from the object side, a first flat glass 10, a second flat glass 11, a first lens 21, a brightness aperture 30, a second lens 22, a filter 40 and a photosensitive chip 50. The first flat glass 10 is a protective glass for the screen, with a thickness of 2.0 mm. The second flat glass 11 has a thickness of 0.3 mm. Its thickness is adjusted according to the external space where the component is located, and the overall structure length can be fine-tuned to meet different application requirements. The filter 40 cuts off unnecessary long-wave light and reduces the interference of long-wave light. Both sides of the first lens 21 are aspherical surfaces, and the object side of the first lens 21 is an aspherical surface with an inflection point. Both sides of the second lens 22 are aspherical surfaces, and the image side is convex. The use of aspherical surfaces can achieve comprehensive performance balance. This embodiment can achieve TTL less than 5.0 mm, the recognition area is greater than 6.3 mm*6.3 mm, and the chip diagonal size can be less than 1.4 mm, achieving better performance effects, compact structure and adjustable advantages of components.

[0097] The following are the detailed parameters about the component:

[0098]

[0099] Component focal length f = 0.482

[0100] Fno=2.39

[0101] TTL=4.69

[0102] D=1.4

[0103] TTL / f=9.73

[0104] D / f=2.90

[0105]

[0106]

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A biometric identification optical component, comprising, from the object side, a flat glass group, a lens group including a brightness aperture, a filter, and a photosensitive chip, wherein the flat glass group includes a first flat glass and satisfies the following conditional formula: TTL / f<10.3; D / f<4.2; Wherein, TTL is the distance between the object side of the first flat glass and the photosensitive surface of the photosensitive chip, f is the focal length of the lens group, and D is the diagonal length of the photosensitive surface of the photosensitive chip; The lens group including the brightness aperture includes a brightness aperture and a first lens; The flat glass group further includes a second flat glass, and the second flat glass is arranged between the first flat glass and the lens group including the brightness aperture; The lens group including the brightness aperture further includes a second lens; The brightness aperture is arranged between the first lens and the flat glass group, and the first lens is arranged between the brightness aperture and the second lens; or the first lens is arranged between the brightness aperture and the flat glass group, and the brightness aperture is arranged between the first lens and the second lens.

2. The biometric optical component according to claim 1, wherein: The second lens is a plastic lens.

3. The biometric optical component according to claim 1, wherein: The first lens is a lens having an aspherical surface.

4. A biometric optical device, characterized in that: A biometric optical component comprising any one of claims 1 to 3, used for under-screen fingerprint recognition.

5. A biometric optical device, characterized in that: A biometric optical component comprising any one of claims 1 to 3, used for vascular imaging identification.

6. A biometric optical device, characterized in that: A biometric optical component comprising any one of claims 1 to 3, used for iris recognition.

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