CN115797984A

CN115797984A - Optical biological identification module

Info

Publication number: CN115797984A
Application number: CN202211509074.9A
Authority: CN
Inventors: 王炯翰; 洪浚郎; 林碧辉
Original assignee: Yihong Technology Co ltd; Yihong Technology Chengdu Co ltd
Current assignee: Yihong Technology Co ltd; Yihong Technology Chengdu Co ltd
Priority date: 2022-11-29
Filing date: 2022-11-29
Publication date: 2023-03-14
Also published as: TWI833480B; TW202422380A

Abstract

The invention provides an optical biological identification module, comprising: the image capturing lens module comprises a cover plate, a substrate, a plurality of light sources, at least one polarizer and an image capturing lens module. The cover plate is provided with a contact surface and a printing surface, and the printing surface comprises a light transmission area and a plurality of shielding areas. The light source and the image taking lens module are in telecommunication connection with the substrate. The light source may project light energy into an optical path, and the polarizer is located just above the optical path. When the object to be measured is close to the contact surface, the optical path passes through the light-transmitting area to the object to be measured and is reflected to the image taking lens module, and the light-transmitting area is matched with a plurality of shielding areas to shield the interference of an external environment light source and limit the angle of internal light so as to block the light source which can interfere with the object to be measured.

Description

Optical biological identification module

Technical Field

The present invention relates to an identification module, and more particularly to an optical biometric identification module with a non-total reflection design.

Background

The biometric identification includes face, voice, iris, retina, vein, palm print, fingerprint identification, etc. Depending on the sensing method, the biometric device can be classified into optical, capacitive, ultrasonic, and thermal sensing. Generally, an optical biometric device includes a light source, a light guide, and a sensor. The light beam emitted by the light source irradiates an object to be measured (such as a finger, a palm print and the like) pressed on the light guide assembly, and the sensor receives the light beam reflected by the object to be measured so as to identify the biological characteristics.

Taking fingerprint identification as an example, when a finger presses on the light guide element, the convex portion of the fingerprint will contact the light guide element, and the concave portion of the fingerprint will not contact the light guide element. Therefore, the convex part of the fingerprint destroys the total reflection of the light beam in the light guide component, so that the sensor obtains the dark fringe corresponding to the convex part. Meanwhile, the concave part of the fingerprint can not destroy the total reflection of the light beam in the light guide component, so that the sensor can obtain the bright line corresponding to the concave part. Therefore, the light beams corresponding to the convex parts and the concave parts of the fingerprint form a stripe pattern with alternate bright and dark on the light receiving surface of the sensor. The information corresponding to the fingerprint image is calculated by using an algorithm, so that the identity of the user can be identified. However, the conventional optical fingerprint recognition still has many problems to be overcome, for example, when raining, the fingerprint cannot be imaged when the pressing surface is wet, which causes the problems of easy deviation of recognition capability and high manufacturing cost, and is an important issue to be considered in the industry.

Disclosure of Invention

The present invention provides an optical biometric module, wherein a glass cover plate is provided with an opening, and the glass cover plate shields the interference of the external environment light source and limits the angle of the internal light by the opening, so as to achieve the effect of blocking the interference of the fingerprint image light source.

The present invention provides an optical biometric module, which eliminates the interface reflection on the lower surface of the glass cover plate by using a polarized light source, thereby achieving the effect of avoiding affecting the fingerprint image acquisition.

The present invention provides an optical biometric module, which uses a light source to directly illuminate a finger when the finger is not pressed, so as to achieve the effect of dry finger and use in a humid environment.

To achieve the above object, the present invention provides an optical biometric module, comprising: the image capturing lens module comprises a cover plate, a substrate, a plurality of light sources, at least one polarizer and an image capturing lens module. The surface of two sides of apron is contact surface and printing face respectively, the printing face is shielded the region including printing opacity region and a plurality of, printing opacity region has first distance. The base plate is spaced from the cover plate by a distance. The light sources are respectively in telecommunication connection with two sides of the substrate, the distance between the light sources is a second distance, the height between the light sources and the substrate is a distance, and the light sources can project light energy to travel an optical path. The polarizer is located on the optical path. The image capturing lens module is in telecommunication connection with the substrate and is positioned between the light sources. When an object to be measured abuts against the contact surface and is located on the contact surface for a third distance, the optical path passes through the light-transmitting area to the object to be measured to be reflected to the image capturing lens module, the first distance dimension length is greater than the third distance dimension length, and the second distance dimension length is greater than the first distance dimension length.

In a preferred embodiment of the present invention, the cover plate is made of glass or plastic.

In a preferred embodiment of the present invention, the shielding region is made of black material, and can be an ink layer or an appearance indicating pattern layer.

In a preferred embodiment of the present invention, the contact surface is an arc-shaped curved surface.

In a preferred embodiment of the present invention, the cover further includes a touch circuit layer, and the touch circuit layer is located on the shielding region.

In a preferred embodiment of the present invention, the light source is a Vertical Cavity Surface Emitting Laser (VCSEL) or a Light Emitting Diode (LED). The Light Emitting Diode (LED) is made of side light type package, and the height is adjusted by the package method.

In a preferred embodiment of the present invention, the image capturing lens module further includes a filter, and the filter is connected to the polarizer.

In a preferred embodiment of the present invention, the polarizer is located on the light emitting side of the light source.

Drawings

The foregoing and other objects, features, advantages and embodiments of the invention will be more readily understood from the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic side cross-sectional view of an optical biometric module according to a first preferred embodiment of the invention.

FIG. 2 is a schematic side cross-sectional view of an optical biometric module according to a second preferred embodiment of the invention.

FIG. 3 is a schematic side view of a cover plate according to a first preferred embodiment of the present invention.

FIG. 4 is a schematic side view of a cover plate according to a second preferred embodiment of the present invention.

FIG. 5 is a schematic diagram of an image of a normal fingerprint recognized by the optical biometric module according to the present invention in a normal environment.

FIG. 6 is a schematic diagram of an image of a dry finger fingerprint recognized by the optical biometric module in a normal environment according to the present invention.

Fig. 7 is a schematic diagram of an image of a conventional optical biometric module recognizing a fingerprint of a finger in a normal environment.

FIG. 8 is a schematic diagram of an image of a conventional optical biometric module recognizing a finger fingerprint in a normal environment.

FIG. 9 is a schematic diagram of an image of a wet finger fingerprint recognized by the optical biometric module according to the present invention in a wet environment.

FIG. 10 is a schematic view of the fingerprint recognition image of a dry finger of the optical biometric module of the present invention when contacting prickly heat powder and flour.

Fig. 11 is a schematic diagram of an image of a wet finger fingerprint recognized by a conventional optical biometric module in a wet environment.

FIG. 12 is a schematic view of the fingerprint recognition image of a dry finger of a conventional optical biometric module when touching prickly heat powder and flour.

FIG. 13 is a schematic diagram of the incident angle vs. the reflectance of the optical biometric module in p-polarization and s-polarization according to the present invention.

Fig. 14 is a schematic diagram of a comparison experiment of the polarizer in front of the light source and the image capturing lens module according to the present invention.

FIG. 15A is a schematic side view of a cross-sectional structure of an optical biometric module according to an embodiment of the present invention with a smaller first distance.

FIG. 15B is a schematic view of an identification image of the optical biometric module of the present invention when the first distance is small.

FIG. 16A is a schematic side view of a cross-sectional structure of an optical biometric module of the present invention with a moderate first distance.

FIG. 16B is a schematic view of an identification image of the optical biometric module of the present invention when the first distance is moderate.

FIG. 17A is a schematic side view of a cross-sectional structure of an optical biometric module according to the present invention with a larger first distance.

FIG. 17B is a schematic view of an identification image of the optical biometric module of the present invention when the first distance is larger.

FIG. 18A is a schematic side view of a cross-sectional structure of an optical biometric module according to the present invention when the first distance is too large.

FIG. 18B is a schematic view of an identification image of the optical biometric module according to the present invention when the first distance is too large.

In accordance with conventional practice, the various features and elements of the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the particular features and elements of the invention. Moreover, the same or similar reference numbers will be used throughout the drawings to refer to similar components and parts.

In the figure, 1-cover plate

11. 11a, 11 b-contact surface

12 to printed side

121-light transmitting region

122-shielded area

13-touch line layer

14-opening area

2-substrate

3-light source

4-polarizer

5-image taking lens module

6-test substance

9-optical path

D1 to the first distance

D2 to the second distance

D3 to third distance

S-spacing

H-height.

Detailed Description

For the purpose of facilitating the examination of the objects, shape, structural features and functions of the present invention, further understanding and appreciation are now provided by the following detailed description of the preferred embodiments of the invention in conjunction with the accompanying drawings.

The following disclosure provides various embodiments, or examples, for implementing various features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure, but are not intended to be limiting; the size and shape of the elements are also not limited by the disclosed ranges or values, but may depend on the processing conditions of the elements or the desired characteristics. For example, the technical features of the present invention are described using cross-sectional views, which are schematic illustrations of idealized embodiments. Thus, variations in the shapes of the illustrations as a result of manufacturing processes and/or tolerances are to be expected and should not be construed as limiting.

Furthermore, spatially relative terms, such as "below," "below …," "below," "above …," and "above," are used for ease of describing the relationship between elements or features depicted in the drawings; spatially relative terms may encompass different orientations of the component in use or operation in addition to the orientation depicted in the figures.

Please refer to fig. 1 to 4, which are schematic side sectional views of an optical biometric module and a cover plate according to several preferred embodiments of the present invention. The invention provides an optical biological identification module, comprising: the image capturing lens module comprises a cover plate 1, a substrate 2, a plurality of light sources 3, at least one polarizer 4 and an image capturing lens module 5. The cover plate 1 is made of glass or plastic. The glass substrate may be a chemically strengthened or physically strengthened glass substrate, or may be an unreinforced glass substrate. The plastic substrate may be Polycarbonate (PC) or polymethyl methacrylate (PMMA), but not limited thereto. The two side surfaces of the cover plate 1 are a contact surface 11 and a printing surface 12, respectively, and the contact surface 11 may be a plane. Of course, in the preferred embodiment of the present invention, the contact surfaces 11a and 11b may be curved surfaces, which are convex upward or concave downward.

The printing surface 12 includes a light-transmitting area 121 and a plurality of shielding areas 122, wherein the light-transmitting area 121 has a first distance D1. The shielding region 122 is made of black material, and may be an ink layer or an appearance indicating pattern layer. When the shielding region 122 is an ink layer, a black ink material is selected. When the shielding region 122 is a pattern layer, the pattern layer or the Black Matrix layer (i.e., the Black Matrix shielding region 122) is formed by a screen printing plate of a printing process, and a semi-transparent material is selected to allow a part of the light beams with a wavelength to pass through, and allow another part of the light beams with a wavelength to meet the requirements of guidance and design.

In the preferred embodiment of the present invention, the cover plate 1 further includes a touch circuit layer 13, and the touch circuit layer 13 is located on the shielding region 122. The cover plate 1 further comprises an open area 14, and the open area 14 can be printed with light-penetrating ink. The position of the shielding area 122 corresponding to the light source 3, which is far away from the proper position of the module, can be printed with semitransparent ink, and the touch circuit layer 13 provides a number key function, so that the combination password unlocking is realized, and meanwhile, the indication function is provided, and the cover plate 1 can achieve the integration effect and the aesthetic requirement by integral matching.

The base plate 2 is spaced apart from the cover plate 1 by a distance S. The light sources 3 are respectively connected with two sides of the substrate 2 in a telecommunication way, the light sources 3 are spaced by a second distance D2, the light sources 3 are spaced by a height H from the substrate 2, and the light sources 3 can project light energy to travel through an optical path 9. In a preferred embodiment of the present invention, the light source 3 is a Vertical Cavity Surface Emitting Laser (VCSEL) or a Light Emitting Diode (LED). The Light Emitting Diode (LED) is made of a side light type package, and the height H is adjusted by a package method or using the thickness of the substrate.

The polarizer 4 is located on the optical path 9. The image capturing lens module 5 is in telecommunication connection with the substrate 2 and is located between the light sources 3. In the preferred embodiment of the present invention, the polarizer 4 is located on the light emitting side of the light source 3 and between the light source 3 and the cover plate 1, although the polarizer 4 may also be located between the cover plate 1 and the image capturing lens module 5, and there may be a plurality of polarizers 4 located between the light source 3 and the cover plate 1 and between the cover plate 1 and the image capturing lens module 5. The image capturing lens module 5 may be a two-piece, three-piece or four-piece lens structure, or a collimator module, and the image capturing lens module 5 further has a filter (not shown in the figure), and the filter is connected to the polarizer 4. For example, in a possible embodiment of the present invention, the image capturing lens module 5 may be replaced by a combination of a light beam directing unit disposed on a light sensing surface of a light sensing element (such as a CCD or a CMOS), and the light beam directing element may be a light collimating layer or an optical fiber.

Wherein, when the object to be measured 6 abuts against the contact surface 11, and is located a third distance D3 on the contact surface 11, and the third distance D3 is the range within which the image capturing lens module 5 can image, the optical path 9 is through the light-transmitting region 121 to the object to be measured 6 is reflected to the image capturing lens module 5, the first distance D1 dimension length is greater than the third distance D3 dimension length, and the second distance D2 dimension length is greater than the first distance D1 dimension length. By the structural arrangement of the optical biometric identification module, the cover plate 1 can shield the interference of the external environment light source and limit the angle of the internal light, and block the light source which can interfere the fingerprint image.

Fig. 5 to 12 are schematic diagrams of images of the present invention and a conventional optical biometric module for recognizing fingerprints of a general finger and dry fingers when the general finger is exposed to prickly heat powder and flour in a normal environment, and for recognizing fingerprints of wet fingers and dry fingers when the general finger is exposed to prickly heat powder and flour in a normal environment. From the above schematic diagrams of the identification images, the identification images of fig. 5 and 6 are clearly clearer than the identification images of fig. 7 and 8, which shows that the optical biometric module of the present invention performs better than the conventional optical biometric module in normal environment, while the identification images of fig. 9 and 10 are more clearly clearer than the identification images of fig. 11 and 12, which shows that the optical biometric module of the present invention performs better than the conventional optical biometric module in wet environment and dry environment.

FIG. 13 is a schematic diagram showing the incident angle vs. the reflectance of the optical biometric module in p-polarization and s-polarization according to the present invention. The optical biological identification module of the invention adopts the light of p polarization state to block the light of s polarization state by the way of the polarizer, and adopts the light of large angle range, the incident angle is about in the range of 45-65 degrees, and the interface reflection of the light can reach the lowest at the moment, so that the image can reach the minimum interference. Fig. 14 is a schematic diagram showing a comparison experiment of the polarizer in front of the light source and the image capturing lens module according to the present invention. The polarizer 4 is disposed in front of the image capturing lens module 5 and generates P-wave light from the light source 3, and the polarizer 4 is optimal when only P-wave light is allowed to enter.

Fig. 15A to 15B are schematic diagrams of a side view cross-sectional structure and an identification image when the first distance of the optical biometric module is small according to the present invention. When the first distance D1 is too small, the recognition image may have a dark area that is not easily recognized. Fig. 16A to 16B are schematic diagrams of a side-view cross-sectional structure and an identification image of the optical biometric module of the invention when the first distance is moderate. When the first distance D1 is in a moderate size, the recognition image presents a relatively good recognition condition. Fig. 17A to 17B are schematic side view cross-sectional structures and identification images of the optical biometric module according to the invention when the first distance is large. When the first distance D1 is larger, the recognition image will have a situation that a bright area is not easily recognized. Fig. 18A to 18B are schematic diagrams of a side view cross-sectional structure and an identification image of the optical biometric module according to the present invention when the first distance is too large. That is, when the first distance D1 is too large, a bright area appears in the recognition image, which is not easy to recognize.

Although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the present invention.

Claims

1. An optical biometric module comprising:

the cover plate is provided with a contact surface and a printing surface on the two side surfaces, the printing surface comprises a light-transmitting area and a plurality of shielding areas, and the light-transmitting area has a first distance;

a substrate spaced apart from the cover plate;

the light sources are respectively connected with two sides of the substrate in a telecommunication way, the distance between the light sources is a second distance, the distance between the light sources and the substrate is a height, and the light sources can project light energy to travel an optical path;

at least one polarizer positioned on the optical path;

the image taking lens module is in telecommunication connection with the substrate and is positioned between the light sources;

when an object to be measured abuts against the contact surface and is located on the contact surface for a third distance, the optical path passes through the light-transmitting area to the object to be measured to be reflected to the image capturing lens module, the first distance dimension length is greater than the third distance dimension length, and the second distance dimension length is greater than the first distance dimension length.

2. The optical biometric module of claim 1, wherein the cover plate is made of glass or plastic.

3. The optical biological recognition module as claimed in claim 1, wherein the shielding region is made of black material, such as ink layer or appearance indication pattern layer.

4. The optical biometric module of claim 1, wherein the contact surface is arcuately curved.

5. The optical biometric module of claim 1, wherein the cover further comprises a touch circuitry layer, the touch circuitry layer being disposed on the shielded area.

6. The optical biometric module of claim 5, wherein the cover further includes an open area, the size of the open area being controlled by the shielded area.

7. The optical biometric module of claim 6, wherein the open area is printable with light transmissive ink, the ink being blue, green, red ink.

8. The optical biometric module of claim 1, wherein the light source is a vertical cavity surface emitting laser or a light emitting diode.

9. The optical biometric module of claim 8, wherein the light emitting diode is fabricated in a side view package and the height is adjusted by the substrate.

10. The optical biometric module of claim 8, wherein the light emitting diode is made of an upward light emitting type package, and the polarizer is located at a position where the light emitting diode emits light and at a position where the image capturing lens module emits light.

11. The optical biometric module of claim 1, wherein the image capturing lens module further comprises a filter, and the filter is connected to the polarizer.

12. The optical biological identification module as claimed in claim 1, wherein the polarizer is located at a light emitting side of the light source.

13. The optical biometric module of claim 1, wherein the image capturing lens module is a collimator module.