TW201824074A - 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 image capturing element has pixel regions. The first collimator includes a first collimating element and a second collimating element. The first collimating element includes a first light transmissive element, a first light absorbing layer, and lens elements. The first light absorbing layer is disposed on the first light transmissive element and has first openings overlapped with the pixel regions. The lens elements are disposed on the first light transmissive element and located in the first openings. The first openings and a light absorbing element of the second collimating element are respectively located at opposite sides of the first light transmissive element, and the light absorbing element has second openings overlapped with the first openings.

Description

Biometric identification device

The invention relates 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 invention provides a biometric identification device.

The biometric identification device of the present invention includes 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, a first light absorbing layer, and a plurality of lens elements. The first light absorbing layer is disposed on the first light transmissive element and has a plurality of first openings that overlap the pixel area. The lens elements are disposed on the first light transmissive element and are respectively located in one of the first openings. The second collimating element includes a light absorbing element. The light absorbing element and the first opening are respectively located on opposite sides of the first light transmitting element, and the light absorbing element has a plurality of second openings overlapping the first opening.

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

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

In an embodiment of the invention, the light absorbing element is a second light absorbing layer. The second light absorbing layer is located between the first light transmitting element and the image capturing element, and the second opening is formed in the second light absorbing layer. The ratio of the aperture of each of the second openings to the height of the first light transmissive element falls within the range of 2 to 20.

In an embodiment of the invention, the aperture of the second opening is less than or equal to the aperture of the first opening.

In an embodiment of the invention, the second collimating element further includes a second light transmissive element and a third light absorbing layer. The second light transmissive element is located between the second light absorbing layer and the image capturing element, and the third light absorbing layer and the second light absorbing layer are respectively located on opposite sides of the second light transmitting element. The third light absorbing layer has a plurality of third openings that overlap the second opening.

In an embodiment of the invention, the aperture of the first opening is greater than or equal to the aperture of the second opening, and the aperture of the second opening is greater than or equal to the aperture of the third opening.

In an embodiment of the invention, the second collimating element further includes a plurality of second light transmissive elements. The second light transmitting element is disposed in the second opening, wherein the refractive index of the second light transmitting element falls within a range of 1.3 to 1.7, respectively, and the height ratio of the aperture of each second opening to the second light transmitting element falls within 2 To the range of 20.

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

The above described features and advantages of the invention will be apparent from the following description.

Reference will now be made in detail to the exemplary embodiments embodiments 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-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.

3 is a schematic illustration of the first collimating element of the first collimator of FIG. 1 showing the front and back sides of the first collimating element. 4 is a first 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 first collimating element 142 and a second collimating element 144 that overlaps the first collimating element 142 .

The first collimating element 142 includes a first light transmissive element 1421, a first light absorbing layer 1422, and a plurality of lens elements 1423. The material of the first light transmissive element 1421 may be glass, polycarbonate (PC), polymethyl methacrylate (PMMA) or other suitable materials. The first light absorbing layer 1422 is disposed on the first light transmitting element 1421 and has a plurality of first openings O1 overlapping the pixel region PR. The lens elements 1423 are disposed on the first light transmissive elements 1421 and are respectively located in one of the first openings O1. The second collimating element 144 includes a light absorbing element 1441. The light absorbing element 1441 and the first opening O1 are respectively located on opposite sides of the first light transmitting element 1421, and the light absorbing element 1441 has a plurality of second openings O2 overlapping the first opening O1.

In the present embodiment, the first light absorption layer 1422 is disposed on the surface S1421A of the first light transmissive element 1421. The light absorbing element 1441 is a second light absorbing layer. The second light absorbing layer (ie, the light absorbing element 1441) is located between the first light transmitting element 1421 and the image capturing element 130, and the second light absorbing layer is disposed, for example, on the surface S1421B of the first light transmitting element 1421 facing the image capturing element 130. And the second opening O2 is formed in the second light absorbing layer. One of the first light absorbing layer 1422 and the second light absorbing layer may 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, but not This is limited to this. In another embodiment, the first light absorbing layer 1422 and the second light absorbing layer may not be disposed on the sidewall surface S1421C of the first light transmitting element 1421.

The lens element 1423 disposed on the light incident side of the first collimator 140 is adapted to concentrate the light beam B' acting through the object to be recognized 10 and passing through the light guiding element 120, thereby helping to allow more of the light beam B' to be transmitted to Image capture component 130.

The material of the first light absorbing layer 1422 and the second light absorbing layer (ie, the light absorbing element 1441) may be, for example, a silicone resin, an acrylic or a photoresist material containing a light absorbing material (for example, carbon) to absorb a large angle of incidence. The light beam of the light element 1421. In addition, even if a light beam incident on the first light transmitting element 1421 at a large angle (for example, the light beam B' shown in FIG. 4) enters the first light transmitting element 1421 through the first opening O1, the first collimating element 142 can be utilized. The light absorbing element 1441 between the image capturing elements 130 absorbs the incident light beam at a large angle, and only passes the small angle incident light beam and transmits it to the image capturing element 130. The first light absorbing layer 1422 and the second light absorbing layer may be formed of the same material and patterned by the same manufacturing process, but not limited thereto. In another embodiment, the first light absorbing layer 1422 and the second light absorbing layer may be formed of different materials and formed in different manufacturing processes.

Whether the light beam entering the first collimator 140 is absorbed by the first light absorbing layer 1422 and the second light absorbing layer (ie, the light absorbing element 1441) may depend on the aperture WO1 of the first opening O1, the aperture WO2 of the second opening O2, and the first through The height H1 of the light element 1421 and the angle of refraction of the light beam B' on the 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 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 element 130. Big. In the case where the aperture WO1 of the first opening O1 and the aperture WO2 of the second opening O2 are constant, the larger the height H1 of the first light transmitting element 1421, the larger the angular range of the light beam B' received by the image capturing element 130. small. In the case where the aperture WO1 of the first opening O1, the aperture WO2 of the second opening O2, and the height H1 of the first light transmitting element 1421 are constant values, the angle of refraction of the beam B' is larger (that is, the incident angle is larger), The more likely it is absorbed by the first light absorbing layer 1422 and the second light absorbing layer (ie, the light absorbing element 1441). In the present embodiment, the refractive index of the first light transmissive element 1421 is greater than 1, and falls, for example, in the range of 1.3 to 1.7. The aperture WO1 of each of the first openings O1 and the height H1 of the first light transmissive element 1421 fall within a range of 2 to 20. The aperture WO2 of each of the second openings O2 and the height H1 of the first light transmitting member 1421 fall within a range of 2 to 20. However, the refractive index of the first light transmissive element 1421, the ratio of the aperture WO1 of each first opening O1 to the height H1 of the first light transmissive element 1421, and the aperture WO2 of each second opening O2 and the height H1 of the first light transmissive element 1421 The ratio may vary depending on different design requirements (eg, the pitch of the image capturing element 130), and is not limited to the above.

By using the first light absorbing layer 1422 and the second light absorbing layer (ie, the light absorbing element 1441) to absorb the large-angle light beam that acts through the light-receiving object 10 and passes through the light-guiding element 120, only a specific angle of the light beam (light beam incident at a small angle) 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 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. In this way, not only the stray light is filtered out, but also the problem that the light beams output from the different second openings O2 interfere with each other is avoided, and the image capturing quality of the image capturing element 130 is improved. Therefore, the biometric device 100 can have good recognition capabilities.

In this embodiment, the aperture WO1 of the first opening O1 and the aperture WO2 of the second opening O2 may be the same, and the first opening O1 and the second opening O2 are aligned with the pixel area PR so as to sequentially pass through the first opening O1. The light beam of the second opening O2 can be transmitted to the image capturing element 130. The shape of the first opening O1 and the second opening O2 is, for example, a circle, but is 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. In addition, 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.

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 (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 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.

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, 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.

7 to 9 are second to fourth cross-sectional views of the first collimator, the image capturing component, and the circuit board of FIGS. 1 and 6, respectively. Figure 10 is a bottom plan view of the first collimating element of the first collimator of Figure 9.

The first collimator 140A of FIG. 7 is similar to the first collimator 140 of FIG. 4, and the first collimator 140A has similar efficacy and advantages as the first collimator 140, and will not be repeated here. The difference between the first collimator 140A of FIG. 7 and the first collimator 140 of FIG. 4 is as follows. In FIG. 4, the aperture WO2 of the second opening O2 is equal to the aperture WO1 of the first opening O1. In FIG. 7, the aperture WO2 of the second opening O2 is smaller than the aperture WO1 of the first opening O1.

By reducing the aperture WO2 of the second opening O2 of the second light absorbing layer (i.e., the light absorbing element 1441 of the second collimating element 144A), it is helpful to filter out more stray light or a beam incident on the first collimator 140A at a large angle. , thereby improving the recognition ability of the biometric identification device.

The first collimator 140B of FIG. 8 is similar to the first collimator 140 of FIG. 4, and the first collimator 140B has similar functions and advantages as the first collimator 140, and will not be repeated here. The difference between the first collimator 140B of FIG. 8 and the first collimator 140 of FIG. 4 is as follows. In FIG. 8, the second collimating element 144B further includes a second light transmissive element 1442 and a third light absorbing layer 1443. The second light transmissive element 1442 is located between the second light absorbing layer (ie, the light absorbing element 1441) and the image capturing element 130. In addition, the third light absorbing layer 1443 and the second light absorbing layer are respectively located on opposite sides of the second light transmitting element 1442.

In this embodiment, the first light absorbing layer 1422 and the second light absorbing layer (ie, the light absorbing element 1441) are respectively disposed on the opposite surfaces S1421A and S1421B of the first light transmitting element 1421, and the third light absorbing layer 1443 is disposed in the first surface. The second light transmissive element 1442 faces the surface S1442A of the image capturing element 130. The second light transmissive element 1442 can be fixed to one side of the first light transmissive element 1421 and formed with the second light absorbing layer (ie, the light absorbing element 1441) by a connecting mechanism or an adhesive layer (for example, an optical adhesive), but limit. In another embodiment, the second light absorbing layer (ie, the light absorbing element 1441) and the third light absorbing layer 1443 are respectively disposed on the opposite surfaces S1442B and S1442A of the second light transmitting element 1442, and the first light transmitting element 1421 One side of the second light-absorbing layer can be fixed to the second light-transmitting element 1442 by a connecting mechanism or an adhesive layer (for example, an optical glue). In still another embodiment, the second light absorbing layer may be pre-formed on the third light transmissive element (not shown), and the third light transmissive element may be fixed to the first light transmissive element 1421 by a connecting mechanism or an adhesive layer. Between the second light transmissive elements 1442. In a further embodiment, the third light absorbing layer 1443 can be further disposed on the sidewall surface S1442C of the second light transmissive element 1442, but not limited thereto.

The third light absorbing layer 1443 has a plurality of third openings O3 overlapping the second opening O2. The aperture WO1 of the first opening O1 may be greater than or equal to the aperture WO2 of the second opening O2, and the aperture WO2 of the second opening O2 may be greater than or equal to the aperture WO3 of the third opening O3. In the present embodiment, the aperture WO1 of the first opening O1, the aperture WO2 of the second opening O2, and the aperture WO3 of the third opening O3 are the same. Further, the first opening O1, the second opening O2, and the third opening O3 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. The shape of the first opening O1, the second opening O2, and the third opening O3 may be a circle, a triangle, a quadrangle, a pentagon, or other polygons. In addition, the first opening O1, the second opening O2, and the third opening O3 are aligned with the pixel region PR, so that the light beams sequentially passing through the first opening O1, the second opening O2, and the third opening O3 can be transmitted to the image capturing component. 130.

The material of the third light absorbing layer 1443 may be the same or similar to that of the first light absorbing layer 1422 and the second light absorbing layer (ie, the light absorbing element 1441), and will not be repeated here. The arrangement of the second light transmissive element 1442 and the third light absorbing layer 1443 helps to filter out more stray light or a large angle incident light beam of the first collimator 140B, thereby enhancing the recognition capability of the biometric identification device.

In the present embodiment, the refractive index of the second light transmissive element 1442 is greater than 1, and falls, for example, in the range of 1.3 to 1.7. The ratio of the aperture WO3 of each of the third openings O3 to the height H2 of the second light transmitting member 1442 falls within the range of 2 to 20. However, the refractive index of the second light transmissive element 1442 and the ratio of the aperture WO3 of each third opening O3 to the height H2 of the second light transmissive element 1442 may be different according to different design requirements (eg, the pitch of the image capturing element 130 (pitch) )) changes, not limited to the above.

Referring to FIGS. 9 and 10, the first collimator 140C of FIG. 9 is similar to the first collimator 140 of FIG. 4, and the first collimator 140C has similar functions and advantages as the first collimator 140. In addition, the top view of the first collimating element 142C of FIG. 9 can refer to FIG. 3 and the corresponding paragraphs of the specification, and will not be repeated here. The difference between the first collimator 140C of FIG. 9 and the first collimator 140 of FIG. 4 is as follows. Compared with the first collimating element 142 of FIG. 4, the first light absorbing layer 1422 of the first collimating element 142C of FIG. 9 is disposed on the sidewall surface S1421C of the first light transmissive element 1421 and further extends to the surface S1421B to The surface is covered by the surface S1421B, but not limited thereto. In another embodiment, the first light absorbing layer 1422 may not be disposed on the surface S1421B of the first light transmissive element 1421 and the sidewall surface S1421C.

Additionally, the second collimating element 144C of FIG. 9 further includes a plurality of second light transmissive elements 1442 as compared to the second collimating element 144 of FIG. The second light transmitting element 1442 is disposed in the second opening O2. Specifically, the second light transmissive elements 1442 are spaced apart and overlapped with the first opening O1. The light absorbing element 1441 surrounds the second light transmitting element 1442 and covers the sidewall of the second light transmitting element 1442. The second light transmissive element 1442 is, for example, in close contact with the light absorbing element 1441, and there is no air gap between the second light transmissive element 1442 and the light absorbing element 1441. That is, the width W1442 of the second light transmissive element 1442 is equal to the aperture WO2 of the second opening O2, respectively.

The second collimating element 144C can be fixed to the first collimating element 142C by a connecting mechanism or an adhesive layer. When the refractive index of the light transmitting medium (eg, air or optical glue) between the first collimating element 142C and the second collimating element 144C 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 second light transmissive element 1442 may be a silicone or acrylic light transmissive material.

Whether the light beam entering the second collimating element 144C is absorbed by the light absorbing element 1441 may depend on the aperture WO2 of the second opening O2, the height H2 of the second light transmitting element 1442, and the upper surface S1442 of the light beam B' on the second light transmitting element 1442. The angle of refraction (determined by the angle of incidence of the beam B' and the index of refraction of the second light transmissive element 1442). In the case where the height H2 of the second light transmitting member 1442 is constant, the larger 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 WO2 of the second opening O2 is constant, the larger the height H2 of the second light transmitting element 1442, the smaller the angular range of the light beam B' received by the image capturing element 130. In the case where the aperture WO2 of the second opening O2 and the height H2 of the second light transmitting element 1442 are constant values, the larger the angle of refraction of the light beam B' (that is, the larger the incident angle), the more likely it is absorbed by the light absorbing element 1441. . In this embodiment, the refractive indices of the second light transmissive elements 1442 are respectively greater than 1, and fall, for example, in the range of 1.3 to 1.7, respectively, and the apertures WO2 of the second openings O2 and the height H2 of the second light transmissive elements 1442 The ratio falls within the range of 2 to 20. However, the refractive index of the second light transmissive element 1442 and the ratio of the aperture WO2 of each second opening O2 to the height H2 of the second light transmissive element 1442 may be different according to different design requirements (eg, the pitch of the image capturing element 130 (pitch) )) changes, not limited to the above.

By using the first light absorbing layer 1422 and the light absorbing element 1441 to absorb the large-angle light beam (for example, the light beam B1') that acts through the light-receiving object 10 and passes through the light-guiding element 120, a light beam of only a certain angle (a small-angle incident light beam, for example, : The beam B2') is transmitted to the image capturing element 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. In this way, not only the stray light is filtered out, but also the problem that the light beams B' output from different openings interfere with each other is avoided, and the image capturing quality of the image capturing element 130 is improved. Therefore, the biometric device 100 can have good recognition capabilities.

In summary, in the biometric device of the embodiment of the present invention, 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 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.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

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, 140A, 140B, 140C‧‧‧ first collimator

142, 142C‧‧‧ first collimating element

144, 144A, 144B, 144C‧‧‧ second collimating components

150‧‧‧ boards

160‧‧‧ cover

170‧‧‧Second collimator

172‧‧‧稜鏡

1421‧‧‧First light transmitting element

1422‧‧‧First light absorbing layer

1423‧‧‧ lens elements

1441‧‧‧Light absorbing elements

1442‧‧‧Second light transmitting element

1443‧‧‧ Third light absorbing layer

B, B’, B1’, B2’‧‧‧ beams

BA‧‧‧ bottom corner

C‧‧‧ dent

H1, H2‧‧‧ height

M‧‧‧Microstructure

O1‧‧‧ first opening

O2‧‧‧ second opening

O3‧‧‧ third opening

PR‧‧‧Pixel Area

S, S', S1421A, S1421B, S1442A, S1442B‧‧‧ surface

S1‧‧‧ first reflective surface

S2‧‧‧ second reflecting surface

S1442‧‧‧ upper surface

S1421C, S1442C‧‧‧ side wall surface

TA‧‧‧ top angle

W1442‧‧‧Width

WO1, WO2, WO3‧‧‧ 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 collimating element of the first collimator of FIG. 1. 4 is a first 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. FIG. 6 is a cross-sectional view of a biometric device according to another embodiment of the present invention. 7 to 9 are second to fourth cross-sectional views of the first collimator, the image capturing component, and the circuit board of FIGS. 1 and 6, respectively. Figure 10 is a bottom plan view of the first collimating element of the first collimator of Figure 9.

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 first collimating element, including a first light transmitting element, a first light absorbing layer, and a plurality of a lens element, the first light absorbing layer is disposed on the first light transmissive element and has a plurality of first openings overlapping the plurality of pixel regions, and the plurality of lens elements are disposed at the first light transmissive And the second collimating element includes a light absorbing element, wherein the light absorbing element and the plurality of first openings are respectively located on opposite sides of the first light transmitting element, and The light absorbing element has a plurality of second openings that overlap the plurality of first openings. 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 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 identification device of claim 1, wherein a height ratio of an aperture of each of the plurality of first openings to the first light transmissive element falls within a range of 2 to 20. The biometric identification device of claim 1, wherein the light absorbing element is a second light absorbing layer, and the second light absorbing layer is located between the first light transmitting element and the image capturing element. And the plurality of second openings are formed in the second light absorbing layer, and a height ratio of an aperture of each of the plurality of second openings to the first light transmitting element falls within a range of 2 to 20. The biometric device of claim 5, wherein the plurality of second openings have an aperture that is less than or equal to an aperture of the plurality of first openings. The biometric device of claim 5, wherein the second collimating element further comprises a second light transmitting element and a third light absorbing layer, wherein the second light transmitting element is located in the second light absorbing layer Between the image capturing member and the third light absorbing layer and the second light absorbing layer respectively located on opposite sides of the second light transmitting element, the third light absorbing layer has an overlap with the plurality of light absorbing layers a plurality of third openings of the second opening. The biometric device of claim 7, wherein the plurality of first openings have an aperture greater than or equal to the apertures of the plurality of second openings, and the apertures of the plurality of second openings are greater than or An aperture equal to the plurality of third openings. The biometric identification device of claim 1, wherein the second collimating element further comprises a plurality of second light transmissive elements, and the plurality of second light transmissive elements are disposed in the plurality of second In the opening, wherein the refractive indices of the plurality of second light transmitting elements respectively fall within a range of 1.3 to 1.7, and the height ratio of the apertures of each of the plurality of second openings to the second light transmitting element falls 2 to 20 range. The biometric identification device of claim 1, further comprising: a second collimator located between the light guiding element and the first collimator, the second collimator comprising a plurality of And the apex angles of the plurality of turns are respectively directed to the light guiding elements.