TWM553004U - Biological feature identification device - Google Patents

Abstract

A biological feature identification device including a light source, a light guide element, an image capturing element, and a first collimator is provided. The light source is adapted to provide a light beam. The light guide element is located on a transmission path of the light beam. The image capturing element is located below the light guide element and has pixel regions. The first collimator is located between the light guide element and the image capturing element, wherein the first collimator includes a light transmissive element and a light absorbing layer. The light transmissive element has a first surface and a second surface. The light absorbing layer is disposed on the first surface and the second surface and has first openings exposing the first surface and second openings exposing the second surface. The first openings and the second openings are overlapped with the pixel regions and have same aperture size.

Description

Biometric identification device

The novel creation is related to a biometric identification device.

The types of biometrics include face, sound, iris, retina, vein, fingerprint, and palmprint recognition. Since each person's fingerprint is unique and the fingerprint is not easy to change with age or physical health, the fingerprint identification device has become the most popular biometric identification device. According to the different sensing methods, the fingerprint identification device can be divided into optical and capacitive. When the capacitive fingerprint identification device is assembled in an electronic product (for example, a mobile phone or a tablet computer), a cover lens is disposed above the capacitive fingerprint identification device. In general, additional processing (eg, drilling or thinning) of the protective element is required to enable the capacitive fingerprinting device to sense the change in capacitance or electric field caused by a finger touch.

Compared with the capacitive fingerprint identification device, the optical fingerprint identification device captures light that easily penetrates the protection component for fingerprint recognition, and can eliminate the need for additional processing of the protection component, thereby facilitating the combination with the electronic product.

The optical fingerprint identification device generally includes a light source, an image capturing component, and a light transmitting component. The light source is used to emit a light beam to illuminate a finger pressed against the light transmissive element. Finger fingerprints are made up of a number of irregular ridges and indentations. The beams reflected by the ridges and the indentations form a fingerprint image that is interlaced on the receiving surface of the image capturing element. The image capture component converts the fingerprint image into corresponding image information and inputs the image information to the processing unit. The processing unit may use an algorithm to calculate image information corresponding to the fingerprint for identification of the user. However, in the above image capturing process, the light beam reflected by the fingerprint is easily transmitted to the image capturing component, which results in poor image quality and affects the recognition result.

The novel creation provides a biometric identification device.

The biometric identification device created by the present invention comprises a light source, a light guiding element, an image capturing element and a first collimator. The light source is adapted to provide a light beam. The light guiding element is located on the transmission path of the light beam. The image capturing component is located below the light guiding component and has a plurality of pixel regions. The first collimator is located between the light guiding element and the image capturing element, wherein the first collimator comprises a light transmitting element and a light absorbing layer. The light transmissive element has a first surface and a second surface between the first surface and the image capture element. The light absorbing layer is disposed on the first surface and the second surface and has a plurality of first openings exposing the first surface and a plurality of second openings exposing the second surface, wherein the first opening and the second opening overlap the pixel area And the first opening has the same aperture as the second opening.

In an embodiment of the present invention, the light guiding element has a light exiting portion and a light incident portion connected to the light exiting portion. The light source and the image capturing component are located below the light exiting portion. The light incident portion is located between the light source and the light exit portion.

In an embodiment of the novel creation, the light source is located on a side of the light guiding element.

In an embodiment of the present invention, the light guiding element is formed with a plurality of microstructures facing the surface of the first collimator. The microstructure is convex or concave on the surface.

In an embodiment of the present invention, the refractive index of the light-transmitting member described above falls within the range of 1.3 to 1.7.

In an embodiment of the present invention, the height ratio of the aperture of each of the first openings to the light transmitting element falls within a range of 2 to 20.

In an embodiment of the present invention, the light transmissive element further has a side wall surface connecting the first surface and the second surface, and the light absorbing layer is further disposed on the side wall surface.

In an embodiment of the present invention, the biometric device further includes a cover plate, wherein the light guiding element is located between the cover plate and the first collimator.

In an embodiment of the present invention, the biometric device further includes a second collimator. The second collimator is located between the light guiding element and the first collimator.

In an embodiment of the novel creation, the second collimator includes a plurality of turns. The top corner of the cymbal refers to the light guide element.

Based on the above, in the biometric device of the presently-created embodiment, by modulating the apertures of the first opening and the second opening to absorb the large-angle beam that acts through the object to be recognized and passes through the light guiding element, it is transmitted to The beam of the image capturing component is collimated to improve the image quality of the image capturing component. Therefore, the biometric device can have good recognition capabilities.

The above described features and advantages of the present invention will become more apparent and understood from the following description.

Reference will now be made in detail to the exemplary embodiments of the embodiments herein Wherever possible, the same element symbols are used in the drawings and the description

1 is a schematic cross-sectional view of a biometric device according to an embodiment of the present invention. Referring to FIG. 1 , the biometric device 100 is, for example, a fingerprint identification device for identifying the fingerprint of the object 10 to be identified, but is not limited thereto. In another embodiment, the biometric device 100 can also be used to identify a combination of at least two of a vein, a palm print, or a fingerprint, a vein, and a palm print.

The biometric device 100 includes a light source 110, a light guiding element 120, an image capturing element 130, and a first collimator 140.

Light source 110 is adapted to provide beam B. Light source 110 can be a non-visible light source or a visible light source. That is, the light beam B may be invisible light (eg, infrared light) or visible light (eg, red light, blue light, green light, or a combination thereof). Alternatively, light source 110 can be a combination of a non-visible light source and a visible light source. For example, light source 110 can include a plurality of light emitting elements 112. Light-emitting element 112 can be a light-emitting diode or other suitable type of light-emitting element. FIG. 1 schematically shows two light-emitting elements 112 with two light-emitting elements 112 on opposite sides of the image capture element 130. However, the number and arrangement of the light-emitting elements 112 can be changed as needed, and not limited thereto.

The light guiding element 120 is located on the transmission path of the light beam B, and is adapted to direct the light beam B provided by the light source 110 to the object to be recognized 10. For example, the material of the light guiding element 110 may be glass, polycarbonate (PC), polymethyl methacrylate (PMMA) or other suitable materials. In this embodiment, the light source 110 and the image capturing component 130 are located on the same side of the light guiding component 120. The biometric device 100 further includes a circuit board 150. The light source 110 is disposed on the circuit board 150 and is electrically connected to the circuit board 150. The light guiding element 120 has a light exiting portion 122 and at least one light incident portion 124 connected to the light exiting portion 122. The light source 110 and the image capturing component 130 are located below the light exiting portion 122 , and the light source 110 is located beside the image capturing component 130 . The light incident portion 124 is located between the light source 110 and the light exit portion 122. In detail, the light incident portion 124 may be fixed to the circuit board 150, and the light incident portion 124 has a recess C. The recess C and the circuit board 150 enclose a space in which the light source 110 is housed. In another embodiment, at least one of the light incident portion 124 and the circuit board 150 may have a recess (not shown) to accommodate the light source 110. In another embodiment, the light incident portion 124 and the circuit board 150 may be fixed together by a fixing mechanism (not shown) or an adhesive layer (not shown, for example, an optical glue). In another embodiment, the light incident portion 124 can be fixed on the light source 110 by an adhesive layer (not shown, for example, an optical glue), and the light incident portion 124 can not be in contact with the circuit board 150. FIG. 1 schematically shows two light incident portions 124, and the two light incident portions 124 are located on opposite sides of the light exit portion 122. However, the number and arrangement of the light incident portions 124 can be changed as needed, and is not limited thereto.

2 is an enlarged view of the light guiding element of FIG. 1. Referring to FIGS. 1 and 2 , the light beam B emitted from the light source 110 enters the light guiding element 120 from the light incident portion 124 , and the light beam B can be transmitted to the light exit portion 122 via the light incident portion 124 . The surface S of the light guiding element 120 facing the first collimator 140 can be selectively formed with a plurality of microstructures M (not shown in FIG. 1 , please refer to FIG. 2 ). The microstructure M is adapted to change the direction of transmission of the beam B such that the beam B reflected by the microstructure M is directed perpendicularly or nearly perpendicularly out of the exit portion 122. As shown in FIG. 2, the microstructure M may protrude from the surface S and may have a first reflective surface S1 and a second reflective surface S2. The first reflective surface S1 and the second reflective surface S2 are connected to each other, wherein the first reflective surface S1 and the second reflective surface S2 are inclined with respect to the surface S, and the oblique directions of the first reflective surface S1 and the second reflective surface S2 are opposite. In one embodiment, the microstructure M, the light exit portion 122, and the light incident portion 124 may be integrally formed, but not limited thereto. In another embodiment, the microstructures M, the light exiting portion 122, and the light incident portion 124 can be separately fabricated and fixed together by a connecting mechanism or an adhesive layer (for example, an optical adhesive). Alternatively, the microstructure M can also be recessed into the surface S. Specifically, the microstructure M may be a depression formed on the surface S. In addition, the number of microstructures M and their distribution may vary according to different needs, and are not limited to the number and distribution shown in FIG.

The surface S' of the light-emitting portion 122 outputting the light beam B is opposed to the surface S on which the microstructure M is formed. In an embodiment, the surface S' may be a pressing surface for pressing the object to be recognized 10. Under the structure in which the surface S' is a pressing surface, as shown in FIG. 2, the light beam B from the light source 110 sequentially passes through the light incident portion 124 and the light exit portion 122, and total internal reflection (TIR) occurs on the surface S'. Then, it is sequentially reflected by the second reflecting surface S2 and the first reflecting surface S1, and the surface S' is emitted vertically or nearly vertically.

Alternatively, as shown in FIG. 1, the biometric device 100 may further include a cover plate 160 for the object 10 to be pressed. The cover plate 160 is located above the light guiding element 120, and the light guiding element 120 is located between the cover plate 160 and the first collimator 140. The cover plate 160 may be a cover lens of an electronic product (for example, a touch panel or a touch display panel) to be assembled, but is not limited thereto. In an embodiment, the cover plate 160 and the light guiding member 120 may be fixed together by a connecting mechanism or an adhesive layer (for example, an optical adhesive), but not limited thereto. In the case where the cover plate 160 and the light guiding element 120 are fixed by the adhesive layer, the refractive indices of the adhesive layer, the cover plate 160 and the light guiding element 120 may be the same or similar to reduce the interface reflection, thereby improving the light utilization of the biometric device 100. Efficiency and / or image quality. However, in other embodiments, the refractive indices of the adhesive layer, the cover plate 160, and the light guiding element 120 may also be different. Under the structure in which the cover plate 160 is disposed, the light beam B from the light source 110 sequentially passes through the light entering portion 124, the light exit portion 122, and the cover plate 160, and total internal reflection occurs on the surface of the cover plate 160 where the object to be recognized 10 is pressed. The light beam B' acting (e.g., diffused) by the object 10 to be identified passes through the cover plate 160 and the light exit portion 122 in sequence and is transmitted to the surface S. A portion of the light beam B' transmitted to the surface S is reflected by the surface S, and is again transmitted toward the surface of the cover plate 160 where the object 10 is to be pressed. On the other hand, another portion of the light beam B' transmitted to the surface S will exit the light guiding element 120 from the surface S.

The image capturing component 130 is located below the light guiding component 120 and has a plurality of pixel regions PR (shown in FIG. 4) arranged in an array to receive the light beam B′ acting through the object to be identified 10, thereby obtaining a to-be-identified image. Image of object 10. In the present embodiment, the image capturing component 130 includes, for example, a plurality of Charge-Coupled Devices (CCDs) 132 (shown in FIG. 4). The charge coupled device 132 is disposed on the circuit board 150 and electrically connected to the circuit board 150. The area where the charge coupled element 132 is located is the pixel area PR of the image capture element 130. In another embodiment, the image capturing component 130 can include a plurality of complementary metal oxide semiconductors (CMOSs), and the region of the complementary metal oxide semiconductor is the pixel region PR of the image capturing component 130.

The first collimator 140 is located between the light guiding element 120 and the image capturing element 130, and the first collimator 140 is located on the transmission path of the light beam B' after the object 10 is to be recognized. For example, the first collimator 140 can be disposed on the image capturing component 130, and the first collimator 140 and the image capturing component 130 can be fixed by a connecting mechanism or an adhesive layer (eg, an optical adhesive). Together, but not limited to this.

3 is a schematic view of the first collimator of FIG. 1 showing the front and back sides of the first collimator. 4 is a cross-sectional view of the first collimator, the image capturing component, and the circuit board of FIG. 1. Referring to FIGS. 1 , 3 and 4 , the first collimator 140 includes a light transmissive element 142 and a light absorbing layer 144 . The light transmissive element 142 has a first surface S1421, a second surface S1422 between the first surface S1421 and the image capturing element 130, and a sidewall surface S1423 connecting the first surface S1421 and the second surface S1422. The light absorbing layer 144 is disposed on the first surface S1421 and the second surface S1422 and has a plurality of first openings O1 exposing the first surface S1421 and a plurality of second openings O2 exposing the second surface S1422, wherein the first opening O1 The second opening O2 overlaps the area pixel PR, and the aperture WO1 of the first opening O1 is the same as the aperture WO2 of the second opening O2. Further, the first opening O1 and the second opening O2 have the same or substantially the same shape and size. The so-called substantially identical shape and size are considered to be errors caused by the manufacturing process. In addition, the first opening O1 and the second opening O2 are aligned with the pixel area PR, so that the light beams sequentially passing through the first opening O1 and the second opening O2 can be transmitted to the image capturing element 130 (as shown by the light beam B2' of FIG. 4). display). In this embodiment, the size of the pixel region PR may be slightly larger than the aperture WO1 of the first opening O1 and the aperture WO2 of the second opening O2, but not limited thereto. In addition, the light absorbing layer 144 may be further disposed on the sidewall surface S1423 of the light transmitting member 142 to prevent the light beam transmitted in the light transmitting member 142 from being emitted from the sidewall surface S1423. However, in another embodiment, the light absorbing layer 144 may not be disposed on the sidewall surface S1423 of the light transmissive element 142.

When the refractive index of the light transmitting medium (for example, air or optical glue) between the light guiding element 120 and the first collimator 140 is different from the refractive index of the light transmitting element 142, the light beam B' incident on the light transmitting element 142 ( The light beam B1' including the large-angle incident light transmitting element 142 and the light beam B2') incident on the light transmitting element 142 at a small angle may enter the light transmitting element 142 via the first surface S1421 of the light transmitting element 142 via refraction. Thus, the arrangement of the light transmissive elements 142 helps to converge the angle of the beam B' into the first collimator 140, thereby allowing more of the beam B' to be transmitted to the image capture element 130.

The material of the light transmitting member 142 may be glass, polycarbonate (PC), polymethyl methacrylate (PMMA) or other suitable materials. The material of the light absorbing layer 144 may be, for example, a silicone-based or acryl-based material containing a light absorbing material (for example, carbon). In this way, even if the light beam B1 ′ of the large-angle incident light transmitting element 142 and the light beam B2 ′ of the small angle incident light transmitting element 142 enter the light transmitting element 142 through the first opening O1 , the second surface S1422 can be utilized. The light absorbing layer 144 absorbs the light beam B1' incident on the light transmitting element 142 at a large angle, and passes only the light beam B2' incident at a small angle to the light transmitting element 142 and is transmitted to the image capturing element 130.

Whether the light beam entering the first collimator 140 is absorbed by the light absorbing layer 144 on the second surface S1422 may depend on the aperture WO1 of the first opening O1 and the aperture WO2 of the second opening O2, the height H of the light transmitting element 142, and the light beam. B' is the angle of refraction at the first surface S1421 of the light transmitting member 142 (determined by the incident angle of the beam B' and the refractive index of the light transmitting member 142). In the case where the height H of the light transmitting member 142 is constant, the larger the aperture WO1 of the first opening O1 and the aperture WO2 of the second opening O2, the larger the angular range of the light beam B' received by the image capturing member 130. In the case where the aperture WO1 of the first opening O1 and the aperture WO2 of the second opening O2 are constant values, the larger the height H of the light transmitting member 142, the smaller the angular range of the light beam B' received by the image capturing member 130. In the case where the aperture WO1 of the first opening O1, the aperture WO2 of the second opening O2, and the height H of the light transmitting element 142 are constant values, the larger the angle of refraction of the beam B' (that is, the larger the incident angle), the more May be absorbed by the light absorbing layer 144. In the present embodiment, the light transmissive element 142 has a refractive index greater than 1, and falls, for example, in the range of 1.3 to 1.7. Further, the aperture WO1 of each of the first openings O1 (also the aperture WO2 of the second opening O2) and the height H of the light transmitting member 142 fall within a range of 2 to 20. However, the refractive index of the light transmissive element 142 and the height H of the first opening O1 and the height H of the light transmissive element 142 may vary according to different design requirements (eg, the pitch of the image capturing element 130). Not limited to the above.

By absorbing the large-angle light beam (for example, the light beam B1') that acts through the light-guiding element 120 and passes through the light-guiding element 120 by the light-absorbing layer 144, a light beam of only a certain angle (a light beam incident at a small angle, for example, the light beam B2') can be transmitted. To image capture component 130. By appropriately modulating the aperture WO1 of the first opening O1 and the aperture WO2 of the second opening O2, the light beam B' passing through the first collimator 140 can be incident on the image capturing element 130 at an angle of 0 degrees or close to 0 degrees. . In other words, the first collimator 140 helps to collimate the beam that is transmitted to the image capturing element 130. Thus, it not only helps to filter out stray light, but also helps to avoid the problem that the light beams B' output from the different second openings O2 interfere with each other, and the image capturing quality of the image capturing element 130 is improved. Therefore, the biometric device 100 can have good recognition capabilities. FIG. 3 schematically shows that the shape of the first opening O1 and the second opening O2 is circular, but not limited thereto. In other embodiments, the shape of the first opening O1 and the second opening O2 may also be a triangle, a quadrangle, a pentagon or other polygons.

The biometric device 100 can also include other components depending on various needs. For example, biometric device 100 can also include a second collimator 170. The second collimator 170 is located between the light guiding element 120 and the first collimator 140, and the second collimator 170 is located on the transmission path of the light beam B' after the object 10 is to be recognized. For example, the second collimator 170 can be disposed on the surface S, and the light guiding component 120 and the second collimator 170 can be fixed together by a connecting mechanism or an adhesive layer (eg, an optical glue), but not This is limited to this.

The second collimator 170 is adapted to pre-align the beam B' before the beam B' passes through the first collimator 140 to converge the divergence angle of the beam B'. As such, the probability of subsequent passage of beam B' through first collimator 140 can be increased. FIG. 5 is an enlarged view of the light guiding element and the second collimator of FIG. 1. FIG. Referring to FIGS. 1 and 5 , the second collimator 170 may include a plurality of turns 172 , and the apex angles TA of the turns 172 refer to the light guiding elements 120 , respectively. In the present embodiment, the angles of the two bottom corners BA of the respective turns 172 are the same. However, the apex angle TA and the bottom angle BA of the crucible 172 may vary depending on different needs, and are not limited thereto.

6 is a schematic cross-sectional view of a biometric device according to another embodiment of the present invention. The biometric device 100A of FIG. 6 is similar to the biometric device 100 of FIG. 1, and the biometric device 100A has similar functions and advantages as the biometric device 100, and will not be repeated here. The difference between the biometric device 100A of FIG. 6 and the biometric device 100 of FIG. 1 is that the position of the light source 110 is different. In detail, in the embodiment of FIG. 6, the light source 110 is located on the side of the light guiding element 120A. In this configuration, the light guiding element 120A is, for example, a plate shape, and the light guiding element 120A can omit the light incident portion 124 of the light guiding element 120 of FIG.

In summary, in the biometric device of the presently-created embodiment, by modulating the apertures of the first opening and the second opening to absorb the large-angle beam that acts through the object to be recognized and passes through the light guiding element, The beam that is transmitted to the image capture component is collimated to improve the image quality of the image capture component. Therefore, the biometric device can have good recognition capabilities.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the novel creation, and any person skilled in the art can make some changes without departing from the spirit and scope of the novel creation. Retouching, the scope of protection of this new creation is subject to the definition of the scope of the patent application attached.

10‧‧‧To be identified
100, 100A‧‧‧ biometric identification device
110‧‧‧Light source
112‧‧‧Lighting elements
120, 120A‧‧‧Light guiding elements
122‧‧‧Lighting Department
124‧‧‧Into the Department of Light
130‧‧‧Image capture components
132‧‧‧Charge-coupled components
140‧‧‧First collimator
142‧‧‧Lighting components
144‧‧‧Light absorbing layer
150‧‧‧ boards
160‧‧‧ cover
170‧‧‧Second collimator
172‧‧‧稜鏡
B, B', B1', B2' ‧ ‧ beams
BA‧‧‧ bottom corner
C‧‧‧ dent
H‧‧‧ Height
M‧‧‧Microstructure
O1‧‧‧ first opening
O2‧‧‧ second opening
PR‧‧‧Pixel Area
S, S'‧‧‧ surface
S1‧‧‧ first reflective surface
S2‧‧‧ second reflecting surface
S1421‧‧‧ first surface
S1422‧‧‧ second surface
S1423‧‧‧ side wall
TA‧‧‧ top angle
WO1, WO2‧‧‧ aperture

1 is a schematic cross-sectional view of a biometric device according to an embodiment of the present invention. 2 is an enlarged view of the light guiding element of FIG. 1. 3 is a schematic view of the first collimator of FIG. 1. 4 is a cross-sectional view of the first collimator, the image capturing component, and the circuit board of FIG. 1. FIG. 5 is an enlarged view of the light guiding element and the second collimator of FIG. 1. FIG. 6 is a schematic cross-sectional view of a biometric device according to another embodiment of the present invention.

130‧‧‧Image capture components

132‧‧‧Charge-coupled components

140‧‧‧First collimator

142‧‧‧Lighting components

144‧‧‧Light absorbing layer

150‧‧‧ boards

B’, B1’, B2’‧‧‧ beams

H‧‧‧ Height

O1‧‧‧ first opening

O2‧‧‧ second opening

PR‧‧‧Pixel Area

S1421‧‧‧ first surface

S1422‧‧‧ second surface

S1423‧‧‧ side wall

WO1, WO2‧‧‧ aperture

Claims (10)

A biometric identification device comprising: a light source adapted to provide a light beam; a light guiding element located on a transmission path of the light beam; an image capturing element positioned below the light guiding element and having a plurality of pixel regions; and first a collimator between the light guiding element and the image capturing element, wherein the first collimator comprises: a light transmitting element having a first surface and the first surface and the image a second surface between the elements; and a light absorbing layer disposed on the first surface and the second surface, and the light absorbing layer has a plurality of first openings exposing the first surface and exposed a plurality of second openings of the second surface, wherein the plurality of first openings and the plurality of second openings overlap the pixel region, and the plurality of first openings and the plurality of second The apertures of the openings are the same. The biometric identification device of claim 1, wherein the light guiding element has a light exiting portion and a light incident portion connected to the light exiting portion, the light source and the image capturing component being located together Below the light exit portion, the light incident portion is located between the light source and the light exit portion. The biometric device of claim 1, wherein the light source is located on a side of the light guiding element. The biometric device of claim 1, wherein the light guiding element faces a surface of the first collimator and has a plurality of microstructures, the plurality of microstructures being convex or concave The surface. The biometric device according to claim 1, wherein the light-transmitting element has a refractive index falling within a range of 1.3 to 1.7. The biometric identification device of claim 1, wherein a height ratio of an aperture of each of the plurality of first openings to the light transmissive element falls within a range of 2 to 20. The biometric device of claim 1, wherein the light transmissive element further has a side wall surface connecting the first surface and the second surface, and the light absorbing layer is further disposed on the side On the wall. The biometric identification device of claim 1, further comprising: a cover plate, wherein the light guiding element is located between the cover plate and the first collimator. The biometric identification device of claim 1, further comprising: a second collimator located between the light guiding element and the first collimator. The biometric device of claim 9, wherein the second collimator comprises a plurality of turns, and the top corners of the plurality of turns are respectively directed to the light guiding elements.