TWI631935B - Biometric identification apparatus - Google Patents

Abstract

A biometric device comprising a light guiding element having opposite first and second surfaces, a plurality of optical microstructures formed on the second surface, a light source for emitting a light beam, and an image disposed relative to the second surface of the light guiding element Capture components. Each optical microstructure has at least one reflective surface. The beam is reflected by the reflective surface of each optical microstructure to collimate to direct the first surface of the light element.

Description

Biometric device

This invention relates to an optoelectronic device and, more particularly, to a biometric device.

The types of biometrics include face, sound, iris, retina, veins, and fingerprint 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 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 capacitive fingerprint identification device is provided with a cover lens, and the sensing effect of the capacitive fingerprint recognition device is protected by the protection component. influences. Therefore, optical fingerprint recognition devices have also received much attention.

The optical fingerprint identification device comprises 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 calculate the image information corresponding to the fingerprint by using an algorithm to perform identity recognition 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 device.

According to an embodiment of the invention, the biometric device comprises a light guiding element, a plurality of optical microstructures, a light source and an image capturing element. The light guiding element has opposing first and second surfaces. A plurality of optical microstructures are formed on the second surface of the light guiding element. Each optical microstructure has at least one reflective surface. The light source is used to emit a light beam. The light beam is reflected by at least one reflective surface of each optical microstructure to be collimated to guide the first surface of the light element. The image capture element is disposed relative to the second surface of the light guide element.

In the biometric device according to the embodiment of the present invention, the at least one reflective surface includes a first reflective surface and a second reflective surface, the first reflective surface and the second reflective surface being inclined with respect to the first surface of the light guiding element, and The first reflective surface is opposite to the oblique direction of the second reflective surface, wherein the light beam is sequentially reflected by the first reflective surface and the second reflective surface of each optical microstructure to collimate toward the first portion of the light guiding element A surface is passed.

In the biometric device according to an embodiment of the present invention, the at least one reflecting surface includes a curved surface, wherein the light beam is reflected by the two different portions of the curved surface to collimate to guide the first surface of the light element.

In the biometric device according to an embodiment of the present invention, the biometric device further includes a light transmissive element. The light transmissive element is disposed on the first surface of the light guiding element. The light transmissive element has a pressing surface for pressing the object to be recognized.

In the biometric device according to an embodiment of the present invention, the biometric device further includes a first optical glue. The light transmissive element is coupled to the first surface of the light guiding element through the first optical glue.

In the biometric device according to an embodiment of the present invention, the biometric device further includes a collimating element. The collimating element is disposed between the second surface of the light guiding element and the image capturing element.

In the biometric device according to an embodiment of the present invention, the biometric device further includes a second optical glue. The collimating element is coupled to the image capturing element through the second optical glue.

In the biometric device according to an embodiment of the present invention, the light guiding element further has an outer side wall. The outer sidewall is coupled to the first surface and extends toward a side of the second surface. The light beam enters the light guiding element from the outer sidewall.

In the biometric device according to an embodiment of the present invention, the light guiding element further has an outer side wall, an inner side wall, and a bottom surface. The outer sidewall is coupled to the first surface and extends toward a side of the second surface. The inner sidewall is coupled to the second surface and disposed opposite the outer sidewall. The bottom surface is disposed opposite to the first surface and is coupled between the outer sidewall and the inner sidewall. The light beam enters the light guiding element from the bottom surface of the light guiding element.

In the biometric device according to an embodiment of the present invention, the light beam includes visible light, invisible light, or a combination thereof.

In the biometric device according to the embodiment of the present invention, the light beam is reflected by the object to be recognized by the first surface of the light guiding element, and the image capturing element receives the light beam reflected by the object to be recognized to obtain an image of the object to be identified. .

In the biometric device according to an embodiment of the present invention, the object to be recognized includes a fingerprint, a vein, a palm print, or a combination thereof.

Based on the above, in the biometric device of the embodiment of the present invention, the light beam emitted by the light source can be collimated to guide the first surface of the light element by utilizing the reflection of the first reflective surface and the second reflective surface of the optical microstructure. Further, the light beam reflected by the object to be recognized is transmitted to the image capturing element in a collimated manner. Thereby, the image quality of the biometric device is improved, thereby increasing the recognition capability of the biometric device.

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 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 includes a light guiding component 110 , a plurality of optical microstructures 120 , a light source 130 , and an image capturing component 140 . Light directing element 110 has opposing first surface 112 and second surface 114. In this embodiment, the light guiding element 110 further has an outer sidewall 116, an inner sidewall 118, and a bottom surface 119. The outer sidewall 116 is coupled to the first surface 112 and extends toward the side of the second surface 114. The inner sidewall 118 is coupled to the second surface 114 and disposed opposite the outer sidewall 116. The bottom surface 119 is disposed opposite to the first surface 112 and is coupled between the outer sidewall 116 and the inner sidewall 118. In the present embodiment, the inner side wall 118 and the second surface 114 may define the recess 113, but the invention is not limited thereto. In this embodiment, the material of the light guiding element 110 may be glass, polycarbonate (PC), polymethyl methacrylate (PMMA) or other suitable materials.

A plurality of optical microstructures 120 are formed on the second surface 114 of the light guiding element 110. In this embodiment, the material of the optical microstructure 120 and the material of the light guiding element 110 can be the same. In other words, the optical microstructure 120 and the light guiding element 110 can be integrally formed. However, the present invention is not limited thereto. In other embodiments, the optical microstructures 120 and the light guiding elements 110 may be separately fabricated, and then the optical microstructures 120 are disposed on the second surface 114 of the light guiding elements 110. It is worth noting that each optical microstructure 120 has at least one reflective surface. For example, in the present embodiment, each optical microstructure 120 has a first reflective surface 122 and a second reflective surface 124. The first reflective surface 122 and the second reflective surface 124 are inclined with respect to the first surface 112 of the light guiding element 110, and the oblique directions of the first reflective surface 122 and the second reflective surface 124 are opposite. In this embodiment, the first reflective surface 122 and the second reflective surface 124 of the same optical microstructure 120 may be directly connected, and the optical microstructure 120 may be V-shaped. However, the present invention is not limited thereto. In other embodiments, the optical microstructures 120 may also have other suitable shapes, and at least one reflective surface of each optical microstructure 120 does not have to be a plurality of planes (ie, the first reflective surface 122). And the second reflecting surface 124).

The light source 130 is used to emit the light beam L. In the present embodiment, the light beam L is, for example, invisible light (for example, infrared light). However, the present invention is not limited thereto. In other embodiments, the light beam L may also be visible light (for example, red light, blue light, green light, or a combination thereof) or a combination of visible light and invisible light. In the embodiment, the light source 130 is, for example, a light emitting diode. However, the present invention is not limited thereto, and in other embodiments, the light source 130 may be other suitable types of light-emitting elements. FIG. 1 shows a light source 130 as an example, and the light source 130 is disposed on one side of the light guiding element 110. However, the present invention is not limited thereto. In other embodiments, the number of the light sources 130 may be plural, and/or the light source 130 may be disposed on both sides or three or more sides of the light guiding element 110.

In the present embodiment, the light beam L can enter the light guiding element 110 from the bottom surface 119 of the light guiding element 110. In detail, the biometric device 100 may further include a circuit board 150. The light source 130 can be disposed on the circuit board 150 and electrically connected to the circuit board 150. The bottom surface 119 of the light guiding element 110 can be fixed to the circuit board 150. The bottom surface 119 of the light guiding element 110 may have a recess 119a. The light source 130 is selectively disposed in the space surrounded by the recess 119a and the circuit board 150. The light beam L can be incident on the light guiding element 110 from the recess 119a. However, the present invention is not limited thereto. In another embodiment, the bottom surface 119 of the light guiding element 110 may have no recess 119a, the circuit board 150 may have a recess (not shown), and the light source 130 may be disposed on the recess of the circuit board 150. The bottom surface 119 of the light guiding element 110 is disposed above the recess of the circuit board 150, and the light beam L can also enter the light guiding element 110 from the bottom surface 119 without the recess 119a. It should be noted that the position of the light source 130 and the area where the light beam L is incident on the light guiding element 110 are only for exemplifying the invention and are not intended to limit the present invention. In other embodiments, the light source 130 may also be disposed at other suitable positions. The light beam L may also be incident on the light guiding element 110 from other regions of the light guiding element 110.

The image capture component 140 is disposed relative to the second surface 114 of the light guide component 110. In detail, in the embodiment, the image capturing component 140 can be disposed on the circuit board 150 and electrically connected to the circuit board 150. Further, in this embodiment, the second surface 114 and the inner sidewall 118 of the light guiding element 110 may define a recess 113, and the image capturing component 140 may be disposed in the recess 113 of the light guiding component 110. However, the invention is not limited thereto. The image capturing component 140 has a plurality of pixel regions 142 arranged in an array to receive the light beam L reflected by the object to be recognized 10, thereby obtaining an image of the object 10 to be identified. In this embodiment, the image capturing component 140 can be a charge-coupled device (CCD), a complementary metal oxide semiconductor (CMOS), or other suitable type of image sensor.

In the present embodiment, the biometric device 100 further includes a light transmissive element 160. The light transmissive element 160 is disposed on the first surface 112 of the light guiding element 110. The light transmissive element 160 has a pressing surface 162 that faces the light guiding element 110. The pressing surface 162 is pressed by the object to be recognized 10. In the present embodiment, under normal use, the object to be identified 10 may be a biological feature of a living being, such as a fingerprint, a vein, a palm print, or a combination of at least two of the above. However, the present invention is not limited thereto, and in the case of abnormal use, the object to be identified 10 may also be a forgery such as a fake finger. In the present embodiment, the biometric device 100 further includes a first optical glue 170. The light transmissive element 160 is connectable to the first surface 112 of the light guiding element 110 through the first optical adhesive 170. In this embodiment, the refractive indices of the light transmissive element 160, the first optical adhesive 170, and the light guiding element 110 may be the same or similar to reduce the boundary between the light transmitting element 160 and the first optical adhesive 170 and the first optical The reflection of the interface between the glue 170 and the light guiding element 110 further enhances the light utilization efficiency and/or image quality of the biometric device 100. However, the present invention is not limited thereto. In other embodiments, the refractive indices of the light transmissive element 160, the first optical paste 170, and the light guiding element 110 may also be different.

It should be noted that after the light source 130 emits the light beam L, the light beam L is sequentially reflected by the first reflective surface 122 and the second reflective surface 124 of the optical microstructure 120 to collimate the first surface 112 of the light guiding element 110. In other words, the incident angle of the light beam L entering the first surface 112 through the reflection of the optical microstructure 120 may be 0 degrees or close to 0 degrees (for example, -15 degrees to +15 degrees, wherein the first surface 112 The normal to the direction of the light beam L is clockwise, and the incident angle is a negative value. If the direction from the normal of the first surface 112 to the direction of the light beam L is counterclockwise, the incident angle is a positive value) . The light beam L is reflected by the object to be recognized 10 after passing through the first surface 112 of the light guiding element 110, wherein the reflection includes diffuse reflection. After being reflected by the object to be recognized 10, the light beam L passes through the light-receiving element 110 through the pressing surface 162 of the light-transmitting element 160 to enter the image capturing element 140. The image capturing component 140 receives the light beam L reflected by the object to be recognized 10 to obtain an image of the object 10 to be identified. In particular, by using the reflection of the first reflective surface 122 and the second reflective surface 124 of the optical microstructure 120, the light beam L can be collimated into the identifier 10, and the light beam L reflected by the identifier 10 can be accurately transmitted to the image. The component 140 is captured. Thereby, the image capturing quality of the biometric device 100 is improved, thereby increasing the recognition capability of the biometric device 100.

In the present embodiment, the biometric device 100 can also include a collimating element 180. The collimating element 180 is disposed between the second surface 114 of the light guiding element 110 and the image capturing element 140. For example, in the embodiment, the biometric device 100 further includes a second optical adhesive 190, and the collimating component 180 can be connected to the image capturing component 140 through the second optical adhesive 190, but the invention is not limited thereto. . It is noted that the collimating element 180 has a plurality of light transmissive regions 184. The plurality of light transmissive regions 184 respectively correspond to the plurality of pixel regions 142 of the image capturing component 140. The light beam L reflected by each of the objects to be identified 10 can be transmitted to the corresponding pixel region 142 through a corresponding one of the light transmitting regions 182, and is not easily transferred to the other pixel regions 142. Thereby, the image capturing quality of the biometric device 100 can be further improved. However, the present invention is not limited thereto, and in other embodiments, the biometric device 100 may optionally not include the collimating element 180.

2 is a cross-sectional view of a biometric device according to another embodiment of the present invention. The biometric device 100A of FIG. 2 is similar to the biometric device 100 of FIG. 1 in that the position of the light source 130 of the biometric device 100A is different from the position of the light source 130 of the biometric device 100. In detail, in the embodiment of FIG. 2, the light source 130 can be disposed beside the outer sidewall 116 of the light guiding element 110, and the light beam L can enter the light guiding element 110 from the outer sidewall 116. The biometric device 100A has similar functions and advantages as the biometric device 100 and will not be repeated here.

3 is a cross-sectional view showing a biometric device according to still another embodiment of the present invention. The biometric device 100B of FIG. 3 is similar to the biometric device 100 of FIG. 1 in that the bottom surface 119 of the light guiding element 110 of the biometric device 100B may not be directly disposed on the circuit board 150. The biometric device 100B also includes a support 194. The support 194 may extend from the bottom surface 119 toward the side of the light source 130 to maintain a gap between the bottom surface 119 and the light source 130. In this embodiment, the support 194 may be integrally formed with the light guiding element 110, the circuit board 150 or the light source 130, or be a member other than the light guiding element 110, the circuit board 150, and the light source 130. The biometric device 100B can also include an optical glue 192. The optical glue 192 fills the gap between the bottom surface 119 of the light guiding element 110 and the light source 130 to reduce the loss of the light beam L before it enters the light guiding element 110. The biometric device 100B has similar functions and advantages as the biometric device 100 and will not be repeated here.

4 is a cross-sectional view showing a biometric device according to still another embodiment of the present invention. The biometric device 100C of FIG. 4 is similar to the biometric device 100 of FIG. 1 in that the optical microstructure 120C of the biometric device 100C is different from the optical microstructure 120 of the biometric device 100. In particular, in the embodiment of FIG. 4, at least one reflective surface of each optical microstructure 120C can be a curved surface 126. The light beam L is reflected by two different portions of the curved surface 126 to be collimated to guide the first surface 112 of the light-emitting element 110, thereby being reflected by the object to be recognized 10. After being reflected by the object to be recognized 10, the light beam L passes through the light-receiving element 110 through the pressing surface 162 of the light-transmitting element 160 to enter the image capturing element 140. The image capturing component 140 receives the light beam L to obtain an image of the object 10 to be identified. The biometric device 100C has similar functions and advantages as the biometric device 100 and will not be repeated here.

In summary, the biometric device according to an embodiment of the invention includes a light guiding component, a plurality of optical microstructures, a light source, and an image capturing component. The light guiding element has opposing first and second surfaces. A plurality of optical microstructures are formed on the second surface of the light guiding element. Each optical microstructure has a first reflective surface and a second reflective surface. The first reflecting surface and the second reflecting surface are inclined with respect to the first surface of the light guiding element, and the first reflecting surface and the second reflecting surface are opposite to each other. By the reflection of the first reflective surface and the second reflective surface of the optical microstructure, the light beam emitted by the light source can be collimated to guide the first surface of the light element, so that the light beam reflected by the object to be recognized is collimated toward the image. Take the component transfer. Thereby, the image quality of the biometric device is improved, thereby increasing the recognition capability of the biometric device.

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, 100B, 100C: biometric device 110: light guiding element 112: first surface 113: groove 114: second surface 116: outer side wall 118: inner side wall 119: bottom surface 119a: recess 120 120C: optical microstructure 122: first reflective surface 124: second reflective surface 126: curved surface 130: light source 140: image capturing element 142: pixel area 150: circuit board 160: light transmitting element 162: pressing surface 170: An optical glue 180: collimating element 184: light transmitting region 190: second optical adhesive 192: optical adhesive 194: support L: light beam

1 is a schematic cross-sectional view of a biometric device according to an embodiment of the present invention. 2 is a cross-sectional view of a biometric device according to another embodiment of the present invention. 3 is a cross-sectional view showing a biometric device according to still another embodiment of the present invention. 4 is a cross-sectional view showing a biometric device according to still another embodiment of the present invention.

Claims (10)

A biometric device includes: a light guiding element having opposite first and second surfaces; and a light transmitting element disposed on the first surface of the light guiding element, wherein the light transmitting element has a pressing surface And a plurality of optical microstructures formed on the second surface of the light guiding element, wherein each of the optical microstructures has at least one reflecting surface; a light source for emitting a light beam, wherein And the light beam sequentially enters the light guiding element, passes through the first surface of the light guiding element, is reflected by the pressing surface of the light transmitting element, and is reflected by the reflective surface of each optical microstructure Reflecting to coordinately pass to the first surface of the light guiding element; and image capturing element disposed relative to the second surface of the light guiding element. The biometric device of claim 1, wherein the at least one reflective surface comprises a first reflective surface and a second reflective surface, and the first reflective surface and the second reflective surface are opposite to the light guide The first surface of the element is inclined, and the first reflective surface is opposite to the oblique direction of the second reflective surface, wherein the light beam is sequentially applied by the first reflective surface of each optical microstructure and The second reflective surface reflects to be collimated to the first surface of the light guiding element. The biometric device of claim 1, wherein the at least one reflecting surface comprises a curved surface, wherein the light beam is reflected by two different portions of the curved surface to collimate toward the light guiding member Said first surface transfer. The biometric device according to claim 1, further comprising: The light transmissive element is disposed on the first surface of the light guiding element, wherein the light transmissive element has a pressing surface for pressing the object to be recognized. The biometric device of claim 4, further comprising: a first optical glue, wherein the light transmissive element is coupled to the first surface of the light guiding element through the first optical glue. The biometric device of claim 1, further comprising: a collimating element disposed between the second surface of the light guiding element and the image capturing element. The biometric device of claim 1, wherein the light guiding element further has: an outer sidewall connected to the first surface and extending toward a side of the second surface, wherein the light beam is The outer sidewall enters the light guiding element. The biometric device of claim 1, wherein the light guiding element further has: an outer sidewall connected to the first surface and extending toward a side of the second surface; an inner sidewall, and the a second surface coupled to and disposed opposite the outer sidewall; and a bottom surface disposed opposite the first surface and coupled between the outer sidewall and the inner sidewall, wherein the light beam is from the The bottom surface of the light guiding element enters the light guiding element. The biometric device of claim 1, wherein the light beam is reflected by the object to be recognized after passing through the first surface of the light guiding element, and The image capturing component receives the light beam reflected by the object to be recognized to obtain an image of the object to be recognized. The biometric device of claim 9, wherein the object to be identified comprises a fingerprint, a vein, a palm print, or a combination thereof.