TW201625921A - Optical module of thin BIO-characteristic verification device - Google Patents

Abstract

An optical module of thin bio-characteristic verification device comprises: a first glass plate, a first prism film, a second prism film and an image sensor. The first glass plate has a fingerprint image area, a vein image area, a contact surface, a reflecting interface and a pasting surface. The first prism film is pasted on the pasting surface and is located below the fingerprint image area. The second prism film is pasted on the first prism film. The image sensor is located below the pasting surface and is opposite to the first glass plate.

Description

Optical imaging module for thin biometric identification device

The invention relates to an optical imaging module for a thinned biometric device, in particular for fingerprint and vein scanning, to facilitate the next identification step.

In order to enhance the preservation effect and to make up for the shortcomings of traditional digital identification technologies such as personal passwords, digital keys, hardware keys built into smart chips, etc., more and more identification and The security system uses or adds a biometric device. The fingerprint identification device and the vein identification device of the finger are two common examples in the biometric device.

The biggest problem facing the dual biometric module is still the hardware integration. In the past, the appropriate sensors for different detection targets were configured. For the fingerprint plus vein dual identification module, it is necessary for vein imaging. To set up an image sensor and fingerprint part, it is necessary to use an optical lens to match the image sensor for imaging (or use a capacitive fingerprint sensor). This is mainly due to the optical principle of imaging the two images. Different, in the vein, as long as the infrared light penetrates the finger, the vein image can be observed. However, the fingerprint image must pass through the total reflection phenomenon of the optical mirror to increase the discrimination between the peak and the valley of the fingerprint.

Therefore, in terms of volume, it is observed that the viewing angles (optical paths) of the two images are different. In addition, the configuration of the conventional fingerprint mirror causes the module to become larger; and the capacitive fingerprint is used as mentioned above. Although the sensor can achieve the purpose of volume reduction, the following problems will occur when the end user uses it: (1) The problem of component reliability, in one-to-one (personal) In the following, it is more suitable for the application of capacitive sensors, but if it is in a one-to-many comparison environment (building access control attendance system) its durability is tested. (2) The use of capacitive fingerprint sensors will further increase the price of the overall module.

Taiwan Patent Publication No. 201413596 (hereinafter referred to as 596) is a pre-invention "biometric device and method" proposed by the applicant of the present invention, which can solve the aforementioned deficiency of the conventional dual biometric module. However, the 596 case still uses traditional prisms to achieve the two different light paths required for the dual biometric module. Since the conventional prism is also a light guiding module which not only has a large thickness and a large space, it is not easy to reduce the overall size, and more reflection is performed once, and the resulting image has a problem of nonlinear deformation, so the applicant of the case further The optical imaging module of the thinned biometric device of the present invention was developed and invented.

According to the similar fingerprint vein imaging module on the market, the fingerprint optical imaging module (HS-100) of the manufacturer NEC, the fingerprint vein image capturing method is to simultaneously use the two image sensors to capture the fingerprint and the vein image respectively. The fingerprint vein recognition is performed by combining and combining different image sensors and focal lengths respectively, which can reduce the time for image acquisition and processing, but further increases the cost of the module.

Another manufacturer's M2SYS fingerprint optical imaging module (FUSE-ID), the combination of integrated optical imaging module and fingerprint module on the hardware, makes the whole module size come to 100mm*120mm*74mm, the overall volume It is relatively large, and the system is two image sensors. It is also necessary to take fingerprints and vein images separately in order to make the image taking time relatively long.

In view of the above, the optical imaging module of the thinned biometric device of the present invention has a light prism film attached to a glass substrate and a single image sensing component, so that the overall optical path volume is reduced. The single image sensing component can acquire the fingerprint and the vein image at the same time only by taking the image at one time, which not only greatly reduces the module volume required for the conventional prism, but also reduces the phenomenon of image distortion due to the smaller optical path of the deflection. Further, the purpose of speeding up the system identification processing is further achieved.

A first object of the present invention is to provide a thinned biometric device The optical imaging module can achieve the purpose of obtaining fingerprints and vein images at the same time by simply taking an image sensing component through one image by attaching an optical lens to the fingerprint image area on a glass substrate.

A second object of the present invention is to provide an optical imaging module for a thinned biometric device, which is integrated into an optical imaging module by integrating the optical lens and the glass substrate to further reduce the overall optical path volume. At the same time speed up the system identification processing speed.

In order to achieve the above object, an optical imaging module of a thinned biometric device includes: a first glass substrate, a first optical lens, a second optical lens, and an image sensing element. The first glass substrate comprises: a fingerprint image area, a vein image area, a contact surface, a reflective interface, and a bonding surface. The first optical lens is attached to the bonding surface and located below the fingerprint image area. The second optical lens is attached to the first optical lens. The image sensing component corresponds to the first glass substrate and is located below the bonding surface.

1, 1a, 1b‧‧‧ optical imaging module

11‧‧‧First glass substrate

111‧‧‧Fingerprint area

112‧‧‧ vein image area

113‧‧‧Contact surface

114‧‧‧reflection interface

115‧‧‧Fitting surface

12‧‧‧First optical lens

121‧‧‧Ling mirror microstructure

13‧‧‧Second optical mirror film

131‧‧‧Ling mirror microstructure

14‧‧‧Image sensing components

15‧‧‧Second glass substrate

7, 7b‧‧‧ optical grade adhesive

8‧‧‧ fingers

9‧‧‧Biometric device

91‧‧‧Seat

92‧‧‧ Positioning structure

93‧‧‧Light source unit

94‧‧‧Control Module

1 is a perspective view of a thin imaging biometric device optical imaging module disposed on a biometric device.

2 is a side view showing the first preferred embodiment of the optical imaging module of the thinned biometric device of the present invention.

FIG. 3 is a top plan view of a first preferred embodiment of an optical imaging module of a thinned biometric device according to the present invention and a relative relationship with an image sensing element.

4 is a partially enlarged cross-sectional view showing the optical lens of the first preferred embodiment of the optical imaging module of the thinned biometric device of the present invention.

FIG. 5A is an optical path simulation diagram of attaching the first optical lens to the first glass substrate.

FIG. 5B is a view of attaching the first optical lens to the first glass substrate An optical path simulation of the second glass substrate.

FIG. 5C is a schematic diagram of an optical path of a first preferred embodiment of an optical imaging module of a thinned biometric device according to the present invention.

FIG. 6 is a schematic side view showing a second preferred embodiment of an optical imaging module of a thinned biometric device according to the present invention.

FIG. 7 is a schematic diagram of an optical path of a second preferred embodiment of an optical imaging module of a thinned biometric device according to the present invention.

FIG. 8 is a schematic side view showing a third preferred embodiment of an optical imaging module of a thinned biometric device according to the present invention.

9 is a top plan view showing a third preferred embodiment of an optical imaging module of a thinned biometric device according to the present invention.

In order to more clearly describe the optical imaging module of a thinned biometric device proposed by the present invention, the following will be described in detail in conjunction with the drawings.

Referring to FIG. 1 , FIG. 1 is a perspective view of an optical imaging module of a thinned biometric device disposed on a biometric device. The optical imaging module 1 of the thinned biometric device of the present invention is disposed in a biometric device 9, and the biometric device 9 is used to identify a biometric feature. The fingerprinting device 9 includes a carrier 91, a positioning structure 92, at least one light source unit 93, and a control module 94. In the present invention, the identified portion is a finger 8, especially the first knuckle and the second knuckle portion of the index finger are preferred, and the first knuckle is used for fingerprint recognition, and the second knuckle is used as a vein. Identification is dominant. The finger 8 is attached to the positioning structure 92 of the carrier 91, so that the optical imaging module 1 in the biometric device 9 can further recognize the fingerprint and vein of the finger 8 through the illumination of the light source unit 93. Features are identified by the control module 94.

Referring to FIG. 2, FIG. 3 and FIG. 4, FIG. 2 is a schematic side view showing a first preferred embodiment of an optical imaging module of a thinned biometric device according to the present invention. Figure 3 is A top view of a first preferred embodiment of the optical imaging module of the thinned biometric device of the present invention and a relative relationship with the image sensing element. 4 is a partially enlarged cross-sectional view showing the optical lens of the first preferred embodiment of the optical imaging module of the thinned biometric device of the present invention.

As shown in FIG. 2 and FIG. 3, the optical imaging module 1 of the thinned biometric device of the present invention comprises: a first glass substrate 11, a first optical lens film 12, and a second optical lens film. 13. An image sensing component 14. The first glass substrate 11 includes a fingerprint image area 111, a vein image area 112, a contact surface 113, a reflective interface 114, and a bonding surface 115. The first optical lens 12 is attached to the bonding surface 115 and located below the fingerprint image area 111. The second optical lens film 13 is attached to the first optical lens film 12. The image sensing element 14 corresponds to the first glass substrate 11 and is located below the bonding surface 115. The contact surface 113 is a surface on which the first glass substrate 11 contacts the finger of the user (including the fingertip and the front or the two knuckle portions), that is, the upper surface of the first glass substrate 11. The contact surface 113 is further divided into the fingerprint image area 111 and the vein image area 112 according to the difference in the area of the finger contacting the contact surface 113. The reflective interface 114 is located in the fingerprint image area 111. The other side of the contact surface 113. The bonding surface 115 is the other surface opposite to the contact surface 113, that is, the lower surface of the first glass substrate 11.

The first glass substrate 11 has a function of filtering out visible light, isolating external dust, and pressing the fingerprint as a finger, and may be one of an IR pass filter or a colored glass. The first optical lens film 12 and the second optical lens film 13 are an optical film having a micro-mirror structure through which the deflection direction of the light can be changed. The first optical lens film 12 and the second optical lens film 13 can be formed on the upper layer or the lower layer of the first glass substrate 11 during the identification process, and the fingerprint image can be imaged, but the first optical lens film 12 is formed. The second optical lens mirror 13 is a relatively soft material. If it is placed on the upper surface of the first glass substrate 11 for direct contact with the finger 8 and is easily worn by use, it is mainly placed on the first glass substrate 11 . The first optical lens film 12 and the second optical lens film 13 are protected by the first glass substrate 11 . However, the first glass substrate 11, the first optical lens film 12, and the second optical lens film 13 are bonded by an optical grade bonding glue 7; wherein the optical grade bonding glue 7 has a thickness of about It is 25 μm .

As shown in FIG. 4, the first optical mirror film 12 and the second optical lens film 13 respectively comprise a plurality of arrays of prism mirror microstructures 121 and 131, and a pitch width D determines The degree of discrimination of the fingerprint image, the larger the width D, the more obvious the bright and dark stripes of the fingerprint, but still need to be designed according to the minimum resolution of the image sensing component 14, if the width of D is greater than the minimum resolution of the image sensing component 14. Too much is easy to produce obvious magnified stripes on the image. The height H exhibits a proportional relationship with the width D, which is about 1:2 (H:D), and the heights H and θ 1 further affect the distance of the width D. θ 1 generally determines whether the light is easily refracted to a specific mirror surface and produces total reflection on the reflective interface 114. The larger θ 1 is, the more likely it is to cause total reflection, but the total reflected light amplitude is reduced, and the smaller θ 1 is, the smaller It is not easy to produce total reflection. The second optical mirror film 13 and the image sensing element 14 can generate a complete fingerprint image with discrimination on the reflective interface 114 only within a specific viewing angle range, and the other placement positions can also generate a total reflection image, but the image Furthermore, the index of refraction of the first optical lens 12 and the second optical lens 13 affects the position of the entire fingerprint image, and the larger the refractive index The closer the image is to the center of the image sensing element 14. The thickness L of the first optical lens film 12 and the second optical lens film 13 of the present invention is between 200 μm and 300 μm , wherein the first optical lens 12 and the second optical The prism widths 121 and 131 of the respective mirrors 13 have a pitch width D ranging from 60 μm to 200 μm , depending on the minimum resolution of the image sensing element 14 used. The height H of each of the prismatic microstructures 121 and 131 ranges from 30 μm to 100 μm in a proportional relationship with the width D. The horizontal angle θ 1 of the respective prism mirrors 121 and 131 is θ 1 = 45°.

Referring to FIG. 5A, FIG. 5B, and FIG. 5C, FIG. 5A is an optical path simulation diagram of the first optical lens attached to the first glass substrate. FIG. 5B is an optical path simulation diagram of attaching a second glass substrate to the first glass substrate after attaching the first optical lens. FIG. 5C is a schematic diagram of an optical path of a first preferred embodiment of an optical imaging module of a thinned biometric device according to the present invention. Wherein, the optical path simulation diagram is based on the angle of view of the image sensing component 14 , and the actual situation is the opposite state. Different line types represent different levels of light energy. The main light (dashed line) represents intensity from 1 to 0.66, and secondary light (solid line). The representative intensity is 0.66~0.33, and the light (double solid line) represents the intensity of 0.33~0. The requirement is that the main light (dashed line) can form a total reflection on the reflective interface 114 of the first glass substrate 11. As a result, the texture of the fingerprint can be clearly identified.

As shown in FIG. 5A, the first optical lens film 12 is attached only to the first glass substrate 11. The optical path simulation result shows that the main light (dashed line) is partially reflected on the reflective interface 114. The structure of the first optical lens 12 of one layer does not effectively cause total reflection on the reflective interface 114. As shown in FIG. 5B, the first optical lens 12 is attached to the first glass substrate 11, and then a second glass substrate 15 is attached. The main light (dashed line) is refracted and exits the reflective interface 114. The main light is also unable to effectively produce total reflection. As shown in FIG. 5C, the main light can be made only by the two layers of the first and second optical mirror films 12, 13 which are attached and adhered to the first glass substrate 11 in combination. ) Produces complete total reflection.

Therefore, in the first preferred embodiment of the present invention, the first optical lens film 12 and the second optical lens film 13 are used as a deflecting medium for the light of the fingerprint image area 111, and then appropriately matched. The position of the image sensing component 14 (including the image sensing component using the 16:9 picture) can obtain a total reflection imaging area required for the fingerprint pattern of 11°~26°; that is, As shown in FIG. 3, the viewing angle θ of the second optical mirror film 13 and the image sensing element 14 can be imaged in the range of 11° < θ < 26°, so that the fingerprint image area 111 and the vein image can be perfectly integrated. The optical path of zone 112 is used to achieve fingerprint and vein imaging in the same picture.

In other words, the first and second optical mirror films 12 and 13 which are overlapped and adhered to the two sides of the first glass substrate 11 are attached to the side of the fingerprint image area 111 of the first glass substrate 11 The fingerprint image area 111 of the first glass substrate 11 and the vein image area 112 can simultaneously provide a fingerprint and a vein to detect a contact area with the finger 8. The image sensing component 14 is disposed directly below the middle of the first glass substrate 11 while capturing fingerprints and vein images. Through such a configuration, fingerprints and vein images can be simultaneously captured.

In the other preferred embodiments of the present invention described below, since the components are the same or similar to the foregoing embodiments, the same components and structures will not be described below, and the same components will be directly given the same names. And number, and give the same name for similar components However, after the original number, an additional English letter is added to distinguish it and not to repeat it.

Referring to FIG. 6 and FIG. 7 , FIG. 6 is a schematic side view showing a second preferred embodiment of an optical imaging module of a thinned biometric device according to the present invention. FIG. 7 is a schematic diagram of an optical path of a second preferred embodiment of an optical imaging module of a thinned biometric device according to the present invention. The second preferred embodiment of the optical imaging module of the thinned biometric device of the present invention is different from the first preferred embodiment of FIG. 2 and FIG. 3 in that the present invention is as shown in FIG. 6 and FIG. In the second preferred embodiment, the first optical lens film 12 of the optical imaging module 1a and the second optical lens film 13 are further sandwiched to include a second glass substrate 15. That is, the second glass substrate 15 is attached and attached to the first glass substrate 15 at the center of the first optical lens film 12 and the second optical lens film 13 through the optical grade bonding paste 7 and attached to the first glass. Under the structural combination under the substrate 11, the main light (dashed line) simulated by the optical path can also be made to achieve a complete total reflection phenomenon.

Referring to FIG. 8 and FIG. 9 , FIG. 8 is a schematic side view showing a third preferred embodiment of an optical imaging module of a thinned biometric device according to the present invention. 9 is a top plan view showing a third preferred embodiment of an optical imaging module of a thinned biometric device according to the present invention. The third preferred embodiment of the optical imaging module of the thinned biometric device of the present invention is different from the first preferred embodiment of FIG. 2 and FIG. 3 in that the present invention is as shown in FIG. 8 and FIG. The two corresponding second optical lens films 13 of the optical imaging module 1b of the third preferred embodiment are attached to the first optical lens 12 through the two corresponding optical grade bonding glues 7b. On both sides of the lower side, to reduce the loss of light penetration on each interface.

In summary, the optical imaging module 1 of the thinned biometric device of the present invention comprises: a first glass substrate 11, a first optical lens film 12, a second optical lens film 13, and a Image sensing element 14. The first glass substrate 11 includes a fingerprint image area 111, a vein image area 112, a contact surface 113, a reflective interface 114, and a bonding surface 115. The first optical lens 12 is attached to the bonding surface 115 and located below the fingerprint image area 111. The second optical lens film 13 is attached to the first optical lens film 12. The image sensing element 14 corresponds to the first glass substrate 11 and is located below the bonding surface 115. Therefore, the first glass substrate 11 and the first and second optical lens films 12, 13 The optical imaging module 1 is integrated and integrated in the optical imaging module 1 of the present invention, so that the fingerprint and the vein image can be simultaneously acquired only by the image sensing component 14 at one time, so that the overall optical path volume can be further reduced, and the system identification processing speed is accelerated. The purpose.

The above-mentioned embodiments are not intended to limit the scope of application of the present invention, and the scope of the present invention should be based on the technical spirit defined by the content of the patent application scope of the present invention and the scope thereof. It is to be understood that the scope of the present invention is not limited by the spirit and scope of the present invention, and should be considered as a further embodiment of the present invention.

1‧‧‧Optical imaging module

11‧‧‧First glass substrate

111‧‧‧Fingerprint area

112‧‧‧ vein image area

113‧‧‧Contact surface

114‧‧‧reflection interface

115‧‧‧Fitting surface

12‧‧‧First optical lens

13‧‧‧Second optical mirror film

14‧‧‧Image sensing components

7‧‧‧Optical grade adhesive

Claims (16)

An optical imaging module for a thinned biometric device includes: a first glass substrate comprising: a fingerprint image area, a vein image area, a contact surface, a reflective interface, and a bonding surface; A first optical lens is attached to the bonding surface and located under the fingerprint image area; and a second optical lens film is disposed under the first optical lens film. The optical imaging module of the thinned biometric device of claim 1, wherein a second glass is further sandwiched between the first optical lens and the second optical lens Substrate. The optical imaging module of the thinned biometric device of claim 2, wherein the first glass substrate, the second glass substrate, the first optical lens, and the second optical lens are They are all bonded by an optical grade adhesive. The optical imaging module of the thinned biometric device of claim 1, further comprising an image sensing component corresponding to the first glass substrate and located below the bonding surface. The optical imaging module of the thinned biometric device of claim 1, wherein the first optical lens and the second optical lens have a thickness range L between 200 μm and 300 μm. The optical imaging module of the thinned biometric device of claim 3, wherein the optical adhesive has a thickness of about 25 μm. The optical imaging module of the thinned biometric device of claim 4, wherein the second optical lens and the image sensing element have an angle of view θ of 11°<θ<26° . The optical imaging module of the thinned biometric device of claim 2, wherein the first glass substrate and the second glass substrate are an IR pass filter or a colored glass. one. The optical imaging module of the thinned biometric device of claim 1, wherein the first optical lens and the second optical lens respectively comprise a plurality of arrays of prismatic microstructures. Constructed; each prism mirror microstructure has a pitch width D The range is from 60μm to 200μm; the height H of each of the prismatic microstructures is 30μm~100μm; the height H is proportional to the width D, and the ratio is H:D=1:2; the different microstructures are The horizontal angle θ1 = 45°. An optical imaging module for a thinned biometric device includes: a first glass substrate comprising: a fingerprint image area, a vein image area, a contact surface, a reflective interface, and a bonding surface; a first optical lens is attached to the bonding surface and located under the fingerprint image area; and two corresponding second optical lens films are respectively attached to the lower side of the first optical lens film side. The optical imaging module of the thinned biometric device of claim 10, further comprising an image sensing component corresponding to the first glass substrate and located below the bonding surface. The optical imaging module of the thinned biometric device of claim 10, wherein the first glass substrate, the first optical lens, and the second optical lens are each passed through an optical stage. Apply glue to bond. The optical imaging module of the thinned biometric device of claim 10, wherein the first optical lens and the second optical lens have a thickness L ranging between 200 μm and 300 μm. The optical imaging module of the thinned biometric device of claim 12, wherein the optical grade adhesive has a thickness of about 25 μm. The optical imaging module of the thinned biometric device of claim 10, wherein the first glass substrate is one of an IR pass filter or a colored glass. The optical imaging module of the thinned biometric device of claim 10, wherein the first optical lens and the second optical lens respectively comprise a plurality of arrays of prismatic microstructures The frame width D of each of the prism mirror microstructures ranges from 60 μm to 200 μm; the height H of each of the prism mirror microstructures ranges from 30 μm to 100 μm; the height H is proportional to the width D, and the ratio It is H:D=1:2; the horizontal angle of each of the different mirror microstructures is θ1=45°.