WO2018113124A1

WO2018113124A1 - Biometric identification device

Info

Publication number: WO2018113124A1
Application number: PCT/CN2017/078487
Authority: WO
Inventors: 王炯翰
Original assignee: 创智能科技股份有限公司
Priority date: 2016-12-23
Filing date: 2017-03-29
Publication date: 2018-06-28
Also published as: CN108241823A; TW201824067A

Abstract

Provided is a biometric identification device, comprising light sources, a light guide element, an image-capturing element and a first collimator. The light sources are suitable for providing light beams. The light guide element is located on transmission paths of the light beams. The image-capturing element is located beneath the light guide element, and is provided with a plurality of pixel regions. The first collimator is located between the light guide element and the image-capturing element, and comprises a first collimation element and a second collimation element. The first collimation element comprises a first light-transmitting element and a light-absorbing layer. The light-absorbing layer is arranged on the first light-transmitting element, and is provided with a plurality of openings. The second collimation element and the openings are respectively located on opposite sides of the first light-transmitting element, and the second collimation element comprises a light-absorbing element and a plurality of second light-transmitting elements. The second light-transmitting elements are arranged at intervals, and overlap with the openings. The light-absorbing element surrounds the second light-transmitting elements, and covers side walls of the second light-transmitting elements. The refractive indices of the second light-transmitting elements are respectively greater than 1. The biometric identification device has a good identification capability.

Description

Biometric identification device

Technical field

The invention relates to a biometric identification device.

Background technique

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 capturing component can convert the fingerprint image into corresponding image information and input the image information into 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.

Summary of the invention

The invention provides a biometric identification device.

According to an embodiment of the invention, the biometric device 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 includes a first collimating element and a second collimating element. The first collimating element includes a first light transmissive element and a light absorbing layer. The light absorbing layer is disposed on the first light transmissive element and has a plurality of openings that overlap the pixel area. The second collimating element and the opening are respectively located on opposite sides of the first light transmissive element, and the second collimating element comprises a light absorbing element and a plurality of second light transmissive elements. The second light transmissive elements are spaced apart and overlap the opening. The light absorbing element surrounds the second light transmissive element and covers the sidewall of the second light transmissive element. The refractive indices of the second light transmissive elements are each greater than one.

In the biometrics device according to the 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 the biometric device according to an embodiment of the present invention, the light source is located at a side of the light guiding element.

In the biometrics device according to the embodiment of the present invention, the light guiding member faces the surface of the first collimator to form a plurality of microstructures. The microstructure is convex or concave on the surface.

In the biometrics device according to the embodiment of the present invention, the ratio of the aperture of each opening to the height of the first light transmitting member falls within the range of 2 to 20.

In the biometric device according to the embodiment of the present invention, the refractive index of the second light transmitting member falls within a range of 1.3 to 1.7, respectively, and the width to height ratio of the second light transmitting member falls between 2 and 20, respectively. Within the scope.

In the biometrics device according to the embodiment of the present invention, the light absorbing layer is further disposed on the side wall surface of the first light transmitting member.

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

In the biometric device according to 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 the biometric device according to an embodiment of the present invention, the second collimator includes a plurality of prisms, and the apex angles of the prisms respectively refer to the light guiding elements.

Based on the above, in the biometric device of the embodiment of the present invention, the light beam transmitted to the image capturing element is collimated by the first collimating element and the second collimating element, so that the image capturing quality of the image capturing component is obtained. Upgrade. Therefore, the biometric device can have good recognition capabilities.

DRAWINGS

The drawings are included to provide a further understanding of the invention, and the drawings are incorporated in the specification. The drawings illustrate embodiments of the invention and, together with

1 is a schematic cross-sectional view of a biometric device according to an embodiment of the present invention;

Figure 2 is an enlarged view of the light guiding member of Figure 1;

3A is a top plan view of the first collimating element of the first collimator of FIG. 1;

3B is a bottom view of the first collimating element 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;

4A is another schematic cross-sectional view of the first collimator, the image capturing component, and the circuit board of FIG. 1;

Figure 5 is an enlarged view of the light guiding element and the second collimator of Figure 1;

FIG. 6 is a cross-sectional view of a biometric device according to another embodiment of the present invention.

Description of the reference numerals:

10: the object to be identified;

100, 100A: biometric identification device;

110: a light source;

112: a light-emitting element;

120, 120A: light guiding element;

122: light exiting department;

124: entering the light department;

130: image capturing component;

132: a charge coupled device;

140, 140A: first collimator;

142: a first collimating element;

144: a second collimating element;

150: circuit board;

160: cover plate;

170: a second collimator;

172: prism;

1421: a first light transmissive element;

1422: light absorbing layer;

1441: light absorbing element;

1442: a second light transmissive element;

WO: aperture;

B, B', B1', B2', B3': light beam;

BA: bottom corner;

C: depression;

H1, H2: height;

M: microstructure;

O: opening;

PR: pixel area;

S, S': surface;

S1: a first reflecting surface;

S2: a second reflecting surface;

S1421A, S1442: upper surface;

S1421B: lower surface;

S1421C: side wall surface;

SS: side wall;

TA: top angle;

W1442: Width.

detailed description

Reference will now be made in detail to the exemplary embodiments embodiments Wherever possible, the same element symbols are used in the FIGS.

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 beam B can be invisible (eg, infrared) or visible (eg, red, blue, green, 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 still another embodiment, the light incident portion 124 and the circuit board 150 may be secured together by a securing mechanism (not shown) or an adhesive layer (not shown, such as an optical glue). In still another embodiment, the light incident portion 124 may be fixed on the light source 110 by an adhesive layer (not shown, for example, an optical glue), and the light incident portion 124 may 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 protection element of an electronic product to be assembled (for example, a touch panel or a touch display panel) Cover lens, but not limited to this. 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-emitting portion 122 and the cover plate 160 of the light-receiving portion 124, 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.

3A is a top plan view of the first collimating element of the first collimator of FIG. 1. 3B is a bottom plan view of the first collimating element 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. Referring to FIG. 1 , FIG. 3A , FIG. 3B and FIG. 4 , the first collimator 140 includes a first collimating element 142 and a second collimating element 144 overlapping the first collimating element 142 . In this embodiment, the second collimating element 144 is located between the first collimating element 142 and the image capturing element 130, and the first collimating element 142 and the second collimating element 144 can be connected by a bonding mechanism or an adhesive layer. (for example: optical glue) and fixed together, but not limited to this.

The first collimating element 142 includes a first light transmissive element 1421 and a light absorbing layer 1422. The light absorbing layer 1422 is disposed on the first light transmitting element 1421 and has a plurality of openings O overlapping the pixel region PR. The second collimating element 144 and the opening O are respectively located on opposite sides of the first light transmissive element 1421. That is, the opening O is formed on the surface of the first light transmissive element 1421 away from the second collimating element 144. In the present embodiment, the light absorbing layer 1422 is disposed on the upper surface S1421A of the first light transmitting member 1421, and the opening O is formed in the light absorbing layer 1422 disposed on the upper surface S1421A. The light absorbing layer 1422 may be further disposed on other surfaces of the first light transmissive element 1421 according to different needs. For example, the light absorbing layer 1422 can be further disposed on the sidewall surface S1421C of the first light transmitting element 1421 to prevent the light beam transmitted in the first light transmitting element 1421 from being emitted from the sidewall surface S1421C. In addition, the light absorbing layer 1422 may further extend to the lower surface S1421B of the first light transmissive element 1421 to partially cover the lower surface S1421B, but is not limited thereto. In another embodiment, the light absorbing layer 1422 may not be disposed on the lower surface S1421B of the first light transmissive element 1421 and the sidewall surface S1421C.

The second collimating element 144 includes a light absorbing element 1441 and a plurality of second light transmissive elements 1442. The second light transmissive elements 1442 are spaced apart and overlap the opening O. The light absorbing element 1441 surrounds the second light transmitting element 1442 and covers the sidewall SS of the second light transmitting element 1442. In the present embodiment, the second light transmissive element 1442 is in close contact with the light absorbing element 1441, for example, and there is no air gap between the second light transmissive element 1442 and the light absorbing element 1441.

The refractive index of the first light transmissive element 1421 is greater than one. When the refractive index of the light transmitting medium (for example, air or optical glue) between the light guiding element 120 and the first collimating element 142 is different from the refractive index of the first light transmitting element 1421, the first light transmitting element 1421 is incident. The light beam B' (the light beam B1' including the large-angle incident light transmitting element 142 and the light beam B2' and the light beam B3' of the small-angle incident light transmitting element 142) enters the first surface S1421A of the first light transmitting element 1421 via refraction. A light transmissive element 1421. Accordingly, the arrangement of the first light transmissive elements 1421 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 second collimating element 144. Further, the refractive indices of the second light transmissive elements 1442 are each greater than one. When the refractive index of the light transmitting medium (eg, air or optical glue) between the first collimating element 142 and the second collimating element 144 is different from the refractive index of the second light transmissive element 1442, the second transparent transmitting element is incident The beam B' of 1442 will enter the second light transmissive element 1442 via refraction at the upper surface S1442 of the second light transmissive element 1442. Thus, the provision of the second light transmissive element 1442 helps to converge the angle of the beam B' into the second light transmissive element 1442, thereby allowing more of the light beam B' to be transmitted to the image capture element 130. For example, the material of the first light transmissive element 1421 and the second light transmissive element 1442 may be a silica gel type or an acrylic light transmissive material.

The material of the light absorbing layer 1422 and the light absorbing element 1441 can be, for example, a silica gel-based or acryl-based material containing a light absorbing material (for example, carbon). In this way, even if the light beam B1 ′ and the light beam B2 ′ of the first light transmitting element 1421 and the light beam B3 ′ of the first light transmitting element 1421 incident at a small angle enter the first light transmitting element 1421 through the opening O, The light absorbing element 1441 located between the first collimating element 142 and the image capturing element 130 can absorb the light beam incident on the second collimating element 144 at a large angle (for example, the light beam B1' and the light beam B2'), and only a small angle The light beam B3' incident on the first collimator 140 passes through 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 1422 and the light absorbing element 1441 may depend on the aperture WO of the opening O, the width W144 of the second light transmitting element 1442, the height H1 of the first light transmitting element 1421, and the second. The height H2 of the light transmitting element 1442 and the angle of refraction of the light beam B' at the upper surface S1421A of the first light transmitting element 1421 (determined by the incident angle of the light beam B' and the refractive index of the first light transmitting element 1421) and the like. In the case where the height H1 of the first light transmitting element 1421 and the height H2 of the second light transmitting element 1442 are constant values, the larger the aperture WO of the opening O and the width W1442 of the second light transmitting element 1442, the larger the image capturing element 130 The angle range of the received beam B' is larger. In the case where the aperture WO of the opening O and the width W1442 of the second light transmitting element 1442 are constant values, the height H1 of the first light transmitting element 1421 and the height H2 of the second light transmitting element 1442 are larger, and the image capturing element 130 is larger. The smaller the range of angles of the received beam B'. In the case where the aperture WO of the opening O, the width W144 of the second light transmitting element 1442, the height H1 of the first light transmitting element 1421, and the height H2 of the second light transmitting element 1442 are constant values, the angle of refraction of the light beam B' is higher. Larger (i.e., the larger the incident angle), the more likely it is absorbed by the light absorbing layer 1422 and the light absorbing element 1441. In the present embodiment, the refractive index of the first light transmitting member 1421 falls within the range of 1.3 to 1.7. The refractive indices of the second light transmissive elements 1442 fall within the range of 1.3 to 1.7, respectively. The aperture WO of each opening O and the height H1 of the first light transmissive element 1421 fall within a range of 2 to 20. The ratio of the width W1442 to the height H2 of the second light transmitting member 1442 falls within the range of 2 to 20, respectively. However, the refractive indices of the first light transmissive element 1421 and the second light transmissive element 1442, the ratio of the aperture WO of each opening O to the height H1 of the first light transmissive element 1421, and the ratio of the width W1442 of the second light transmissive element 1442 to the height H2 Can be changed according to different design requirements (for example, the pitch of the image capturing component 130), and Not limited to the above.

By using the light absorbing layer 1422 and the light absorbing element 1441 to absorb the large-angle light beam (for example, the light beam B1' and the light beam B2') that acts through the light-receiving object 10 and passes through the light guiding element 120, the light beam of only a certain angle can be made (the light beam incident at a small angle) For example, the beam B3') is transmitted to the image capturing element 130. 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 via the aperture WO of the appropriate modulation opening O and the width W1442 of the second light transmitting element 1442. . 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 openings O or the second light transmitting elements 1442 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. In the present embodiment, the shape of the cross section of the opening O and the second light transmissive element 1442 is, for example, a circular shape, but is not limited thereto. In other embodiments, the shape of the cross section of the opening O and the second light transmissive element 1442 may also be a triangle, a quadrangle, a pentagon or other polygons.

The aperture WO of the opening O and the width W1442 of the second light transmissive element 1442 may be the same, and the opening O and the second light transmissive element 1442 are aligned with the pixel region PR to sequentially pass the light beam of the opening O and the second light transmissive element 1442. It can be passed to the image capture component 130 (as shown by beam B3' of Figure 4). In this embodiment, the size of the pixel region PR may be slightly larger than the aperture WO of the opening O and the width W1442 of the second transparent component 1442, but not limited thereto.

4A is another cross-sectional view of the first collimator, the image capturing component, and the circuit board of FIG. 1. The first collimator 140A of FIG. 4A is similar to the first collimator 140 of FIG. 4, and the first collimator 140A has similar functions and advantages as the first collimator 140, and will not be repeated here. The first collimator 140A of FIG. 4A differs from the first collimator 140 of FIG. 4 in the relative arrangement relationship of the first collimating element 142 and the second collimating element 144. In detail, in the embodiment of FIG. 4A, the first collimating element 142 is located between the second collimating element 144 and the image capturing element 130. Under this architecture, the light absorbing layer 1422 is disposed on the lower surface S1421B of the first light transmitting member 1421, and the opening O is formed in the light absorbing layer 1422 disposed on the lower surface S1421B. The light absorbing layer 1422 may be further disposed on the sidewall surface S1421C of the first light transmissive element 1421 and may further extend to the upper surface S1421A of the first light transmissive element 1421 to partially cover the upper surface S1421A, but is not limited thereto.

Referring again to FIG. 1, the biometric device 100 may further include other components according to different 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 (or the first collimator 140A) to converge the divergence angle of the beam B'. As such, the probability of subsequent passage of beam B' through first collimator 140 (or first collimator 140A) 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 prisms 172 , and the vertex angles TA of the prisms 172 refer to the light guiding elements 120 , respectively. In the present embodiment, the angles of the two bottom corners BA of the respective prisms 172 are the same. However, the apex angle TA and the bottom angle BA of the prism 172 may vary according to different needs, and are not limited thereto.

FIG. 6 is a 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, the implementation in Figure 6 In the example, 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 embodiment of the present invention, the first collimating component and the second collimating component are used to collimate the light beam transmitted to the image capturing component, so that the image capturing component is taken. Like quality improvement. Therefore, the biometric device can have good recognition capabilities.

Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that The technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the technical solutions of the embodiments of the present invention. range.

Claims

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 component located below the light guiding element and having a plurality of pixel regions;

a first collimator, located between the light guiding element and the image capturing element, wherein the first collimator comprises:

a first collimating element comprising a first light transmissive element and a light absorbing layer disposed on the first light transmissive element and having a plurality of openings overlapping the plurality of pixel regions;

a second collimating element, wherein the second collimating element and the plurality of openings are respectively located on opposite sides of the first light transmissive element, and the second collimating element comprises a light absorbing element and a plurality of second through a plurality of second light transmissive elements spaced apart from each other and overlapping the plurality of openings, the light absorbing elements surrounding the plurality of second light transmissive elements and covering the plurality of second light transmissive elements a sidewall, wherein the plurality of second light transmissive elements have refractive indices greater than one, respectively.
The biometric device according to claim 1, wherein the light guiding element has a light exiting portion and a light incident portion connected to the light exiting portion, and the light source and the image capturing component are co-located in the Below the light exit portion, the light incident portion is located between the light source and the light exit portion.
The biometric device according to claim 1, wherein said light source is located on a side of said light guiding element.
The biometric device according to claim 1, wherein a surface of the light guiding member facing the first collimator is formed with a plurality of microstructures, and the plurality of microstructures are convex or concave. The surface.
The biometric device according to claim 1, wherein a ratio of a height of each of said plurality of openings to said first light transmitting member falls within a range of 2 to 20.
The biometric device according to claim 1, wherein the refractive indices of the plurality of second light transmissive elements respectively fall within a range of 1.3 to 1.7, and the widths of the plurality of second light transmissive elements The ratio to the height falls within the range of 2 to 20, respectively.
The biometric device according to claim 1, wherein the light absorbing layer is further disposed on a side wall surface of the first light transmitting member.
The biometric identification device according to 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 according to claim 1, further comprising:

a second collimator is located between the light guiding element and the first collimator.
The biometric device of claim 9, wherein the second collimator comprises a plurality of prisms, and a vertex angle of the plurality of prisms is respectively directed to the light guiding element.