TWM572005U - Fingerprint identification device - Google Patents

Abstract

A fingerprint identification device includes a light guiding component, a transparent substrate, a light source, and an image sensing component. The light guiding element has a first surface, a second surface opposite the first surface, and a side surface connected between the first surface and the second surface. The transparent substrate is formed on the first surface of the light guiding element and has a pressing surface for pressing by a finger. The light source is used to emit a light beam and is disposed beside the side of the light guiding element. The image sensing element is disposed relative to the second surface of the light guiding element. The pressing surface of the transparent substrate or the second surface of the light guiding member is an irregular rough surface.

Description

Fingerprint identification device

The present invention relates to an optoelectronic device, and more particularly to a fingerprint identification device.

Fingerprint identification, as the mainstream technology of today's biometric identification, can be mainly divided into capacitive and optical. The optical fingerprint identification device includes a light guiding element and an image capturing element. The light guiding element is used to transmit the light beam, and the image capturing component is used to capture the image of the fingerprint. The fingerprint of the finger has a plurality of irregular peaks and troughs. When the beam is irradiated on the peaks and troughs of the fingerprint, the light-receiving surface reflected to the image capturing element forms a stripe pattern of light and dark interlaced, and finally the corresponding algorithm is calculated by using an algorithm. Image information to achieve fingerprint recognition.

In order to enable the light beam reflected by the fingerprint to be directly collimated into the light receiving surface of the image capturing element, a plurality of optical microstructures are disposed on one surface of the light guiding element. Although the optical microstructure can adjust the transmission path of the light beam reflected by the fingerprint, the plurality of optical microstructures are periodically arranged, and the light beam reflected by the fingerprint passes through the plurality of optical microstructures arranged periodically, and originally carries the complete fingerprint. The beam of the image is destroyed by the periodically arranged optical microstructure, which affects the image quality and is not conducive to fingerprint recognition.

The novel creation provides a fingerprint identification device capable of obtaining a good quality fingerprint image.

The fingerprint identification device created by the novel comprises a light guiding component, a transparent substrate, a light source and an image sensing component. The light guiding element has a first surface, a second surface opposite the first surface, and a side surface connected between the first surface and the second surface. The transparent substrate is formed on the first surface of the light guiding element and has a pressing surface for pressing by a finger. The light source is used to emit a light beam and is disposed beside the side of the light guiding element. The image sensing element is disposed relative to the second surface of the light guiding element. The light beam sequentially enters the light guiding element from the side surface of the light guiding element, passes through the pressing surface of the transparent substrate, is reflected by the finger located on the pressing surface, passes through the transparent substrate, the first surface and the second surface of the light guiding element, Transfer to the image sensing component. In particular, the pressing surface of the transparent substrate or the second surface of the light guiding member is an irregular rough surface.

In an embodiment of the present invention, the pressing surface of the transparent substrate is an irregular rough surface, and the roughness of the pressing surface of the transparent substrate is greater than the roughness of the second surface of the light guiding element.

In an embodiment of the present invention, the second surface of the light guiding element is an irregular rough surface, and the roughness of the second surface of the light guiding element is greater than the roughness of the pressing surface of the transparent substrate.

In an embodiment of the present invention, the second surface of the light guiding element has a plurality of microstructures, the pressing surface of the transparent substrate is an irregular rough surface, and the roughness of the second surface of the light guiding element is greater than The roughness of the pressing surface of the transparent substrate.

In an embodiment of the present invention, the microstructure of the second surface of the light guiding element is regularly arranged.

In an embodiment of the novel creation, the irregular rough surface has a roughness greater than 0.001 microns and less than 1 micron.

The fingerprint identification device created by the novel comprises a light guiding component, a plurality of scattering particles, a transparent substrate, a light source and an image sensing component. The light guiding element has a first surface, a second surface opposite the first surface, and a side surface connected between the first surface and the second surface. A plurality of scattering particles are distributed within the light guiding element. The transparent substrate is formed on the first surface of the light guiding element and has a pressing surface for pressing by a finger. The light source is used to emit a light beam and is disposed beside the side of the light guiding element. The image sensing element is disposed relative to the second surface of the light guiding element. The light beam sequentially enters the light guiding element from the side surface of the light guiding element, is scattered by the scattering particles to the pressing surface of the transparent substrate, is reflected by the finger located on the pressing surface, passes through the transparent substrate and the light guiding element, and is transmitted to the image. Sensing element.

In an embodiment of the present invention, the second surface of the light guiding element has a plurality of microstructures, wherein the roughness of the second surface of the light guiding element is greater than the roughness of the pressing surface of the transparent substrate and the light guiding element The roughness of the first surface.

In an embodiment of the present invention, the second surface of the light guiding element has a roughness greater than 0.010 microns and less than 10 microns.

Based on the above, the pressing surface of the transparent substrate or the second surface of the light guiding element of the fingerprint recognition device of the present invention is an irregular rough surface. By the non-periodic structure distribution of the rough surface, after the light beam reflected by the finger passes through the rough surface, the light beam does not carry the image information corresponding to the periodic structure and interferes with the fingerprint information originally carried by the light beam. Thereby, the image sensing component can obtain a fingerprint image of a clear finger and contribute to fingerprint recognition.

In the light guiding element of the fingerprint identification device of another embodiment of the present invention, a plurality of scattering particles are disposed. After passing through the light guiding element, the light beam reflected by the finger is scattered by the scattering particles in the light guiding element without carrying the image information corresponding to the periodic structure and interfering with the fingerprint information originally carried by the light beam. Thereby, the image sensing component can obtain a fingerprint image of a clear finger, which is helpful for fingerprint recognition.

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

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

1 is a cross-sectional view of a fingerprint identification device in accordance with an embodiment of the present invention. Referring to FIG. 1 , the fingerprint identification device 100 includes a light guiding component 110 , a transparent substrate 120 , a light source 130 , and an image sensing component 140 . The light guiding element 110 has a first surface 110a, a second surface 110b opposite to the first surface 110a, and a side surface 110c connected between the first surface 110a and the second surface 110b. For example, in the embodiment, the light guiding element 110 may include a light coupling portion 112 close to the light source 130 and having a side surface 110c and a light guiding portion 114 away from the near light source 130, wherein the thickness T1 of the light coupling portion 112 is greater than the light guiding portion The thickness T2 of the portion 114. The light guiding element 110 further includes a connecting portion 116 connected between the light coupling portion 112 and the light guiding portion 114 and having a gradual thickness T3, where T2 ≤ T3 ≤ T1. However, the novel creation is not limited thereto, and in other embodiments, the light guiding element 110 can also be designed in other forms. In the present embodiment, the material of the light guiding element 110 is, for example, polymethyl methacrylate (PMMA). However, the novel creation is not limited thereto. In other embodiments, the material of the light guiding element 110 may also be other suitable light transmissive materials.

The transparent substrate 120 is formed on the first surface 110a of the light guiding element 110, and has a pressing surface 122a for pressing by the finger F. In the present embodiment, the light guiding element 110 has an upper surface 122 away from the light guiding element 110, and the pressing surface 122a refers to a part of the upper surface 122 of the transparent substrate 120. In the present embodiment, the pressing surface 122a can overlap the light guiding portion 114 of the light guiding element 110 without overlapping the light coupling portion 112 and the connecting portion 116 of the light guiding element 110. For example, in the embodiment, the material of the transparent substrate 120 may be glass, and the transparent substrate 120 may be referred to as a cover glass. However, the novel creation is not limited thereto. In other embodiments, the material of the transparent substrate 120 may also be other suitable materials having high transmittance and withstand voltage.

The light source 130 is configured to emit a light beam L and is disposed beside the side surface 110c of the light guiding element 110. The image sensing element 140 is disposed relative to the second surface 110b of the light guiding element 110. The second surface 110b of the light guiding element 110 is located between the first surface 110a of the light guiding element 110 and the image sensing element 140. In this embodiment, the light source 130 is, for example, a light emitting diode (LED), and the image sensing component 140 can be a charge-coupled device (CCD) sensor or a complementary metal oxide semiconductor (complementary metal oxide semiconductor). CMOS) or other types of sensors, but this new creation is not limited to this.

In the present embodiment, the upper surface 122 of the transparent substrate 120 may further have a non-pressing surface 122b other than the pressing surface 122a, wherein the non-pressing surface 122b is closer to the light source 130 than the pressing surface 122a. In this embodiment, the light beam L sequentially enters the light guiding element 110 from the side surface 110c of the light guiding element 110, is reflected by the non-pressing surface 122b of the transparent substrate 120, passes through the first surface 110a of the light guiding element 110, and is guided. The second surface 110b of the element 110 reflects, passes through the pressing surface 122a of the transparent substrate 120, is reflected by the finger F on the pressing surface 122a, passes through the transparent substrate 120, and the first surface 110a and the second surface of the light guiding element 110 110b is passed to image sensing component 140.

In the present embodiment, the pressing surface 122a of the transparent substrate 120 is an irregular rough surface, and the second surface 110b of the light guiding element 110 is a smooth surface. The roughness of the pressing surface 122a is greater than the roughness of the second surface 110b of the light guiding element 110. Specifically, in the present embodiment, the roughness of the irregular rough surface (for example, the pressing surface 122a) is more than 0.001 μm and less than 1 μm. In detail, the above roughness refers to an Arithmetical mean deviation of the roughness profile (Ra), which is defined as a measurement length taken on a surface profile curve to measure the center line in the length as an axis, and The sum of the enclosed areas divided by the measured length is the centerline average roughness. The larger the value of the roughness, the coarser it is. On the contrary, the smaller the value of the roughness, the smoother it is. In addition, in this embodiment, the upper surface 122 of the transparent substrate 120 need not all be rough surfaces, that is, the pressing surface 122a may be a rough surface, and the non-pressing surface 122b may be a smooth surface, but the novel creation Not limited to this.

In this embodiment, between the light guiding component 110 and the image sensing component 140, other optical components, such as a prism, a collimator, etc., may be optionally included to further enhance The quality of the fingerprint image obtained, but this new creation is not limited to this.

It is worth mentioning that, by the non-periodic structure distribution of the rough surface (for example, the pressing surface 122a), after the light beam L reflected by the finger F passes through the rough surface, the light beam L does not carry the corresponding periodic structure. The image information interferes with the fingerprint information originally carried by the light beam L. Thereby, the image sensing component 140 can obtain the fingerprint image of the clear finger F, which helps to improve the fingerprint recognition capability.

2 is a cross-sectional view of a fingerprint identification device in accordance with another embodiment of the present invention. Referring to FIG. 1 and FIG. 2, the fingerprint identification device 100A of FIG. 2 is similar to the fingerprint identification device 100 of FIG. 1. The main difference between the two is that the second surface 110b of the light guiding element 110A is an irregular rough surface, and is transparent. The pressing surface 122a of the base material 120A is a smooth surface. The fingerprint identification device 100A has similar functions as the fingerprint recognition device 100 and will not be repeated here.

3 is a cross-sectional view of a fingerprint identification device according to still another embodiment of the present invention. Referring to FIG. 1 and FIG. 3, the fingerprint identification device 100B of FIG. 3 is similar to the fingerprint identification device 100 of FIG. 1. The difference between the two is that the second surface 110b of the light guiding component 110B of the fingerprint identification device 100B may not be a smooth surface. The second surface 110b can have a plurality of microstructures MS. In the present embodiment, the plurality of microstructures MS of the second surface 110b may be regularly arranged, and the roughness of the second surface 110b is greater than 0.010 microns and less than 10 microns. The roughness of the second surface 110b refers to an Arithmetical mean deviation of the roughness profile (Ra), which is defined as a measurement length on a surface profile curve to measure the center line of the length as an axis. The value obtained by dividing the sum of the enclosed areas by the measured length is the center line average roughness, wherein the surface contour curve refers to the contour curve of the plurality of microstructures MS itself and does not include the second surface 110b. The contour of the microstructure MS where the enclosed area refers to the area of the plurality of microstructures MS itself and does not include the area of the second surface 110b where the plurality of microstructures MS are located. For example, in this embodiment, the microstructures MS may be prisms, and the angles formed by the respective microstructures MS may be the same or different. However, the novel creation is not limited thereto, and in other embodiments, the microstructure MS may also be a semi-spherical column or other suitable aspect. In this embodiment, the microstructures MS may be arranged at equal intervals or non-equally spaced. However, the novel creation is not limited thereto.

4 is a cross-sectional view of a fingerprint identification device according to still another embodiment of the present invention. Referring to FIG. 4 , the fingerprint identification device 100C includes a light guiding element 110C, scattering particles 150 , a transparent substrate 120 , a light source 130 , and an image sensing element 140 . The light guiding element 110C has a first surface 110a, a second surface 110b opposite to the first surface 110a, and a side surface 110c connected between the first surface 110a and the second surface 110b. The transparent substrate 120 is disposed on the first surface 110a of the light guiding element 110C and has a pressing surface 122a for pressing by the finger F. The light source 130 is configured to emit a light beam L and is disposed beside the side surface 110c of the light guiding element 110C. The image sensing element 140 is disposed relative to the second surface 110b of the light guiding element 110C. In this embodiment, the second surface 110b of the light guiding element 110C and the pressing surface 122a of the transparent substrate 120 may all be smooth surfaces, but the novel creation is not limited thereto.

It is to be noted that a plurality of scattering particles 150 are distributed within the light guiding element 110C. For example, in this embodiment, the distribution density of the scattering particles 150 in the light guiding portion 114 may be greater than the distribution density of the scattering particles 150 in the coupling portion 112 and/or the connecting portion 116. Specifically, in the present embodiment, the scattering particles 150 are mainly distributed in the light guiding portion 114 and are hardly distributed in the light coupling portion 112 and the connecting portion 116. However, the present invention is not limited thereto. In other embodiments, the scattering particles 150 may also be distributed in the light guiding portion 114, the light coupling portion 112, and the connecting portion 116; the distribution of the scattering particles 150 in the light guiding portion 114 The density, the distribution density of the scattering particles 150 in the coupling portion 112, and the distribution density of the scattering particles 150 in the connecting portion 116 may also be substantially equal.

In this embodiment, the light beam L sequentially enters the light guiding element 110C from the side surface 110c of the light guiding element 110C, is reflected by the non-pressing surface 122b of the transparent substrate 120, passes through the transparent substrate 120, and is second by the light guiding element 110C. The surface 110b reflects and is scattered by the scattering particles 150 to the pressing surface 122a of the transparent substrate 120, is reflected by the finger F on the pressing surface 122a, passes through the transparent substrate 120 and the light guiding element 110C, and is transmitted to the image sensing element 140. . Similarly, after the light beam L reflected by the finger F passes through the light guiding element 110C, the light beam L is scattered by the scattering particles 150 in the light guiding element 110C without carrying the image information corresponding to the periodic structure and disturbing the original light beam L. Carrying fingerprint information. Thereby, the image sensing component 140 can obtain a fingerprint image of the clear finger F, which is helpful for fingerprint recognition.

FIG. 5 is a cross-sectional view of a fingerprint identification device according to an embodiment of the present invention. Referring to FIG. 4 and FIG. 5, the fingerprint identification device 100D of FIG. 5 is similar to the fingerprint identification device 100C of FIG. 4, and the difference is that the second surface 110b of the light guiding element 110D may have a plurality of microstructures MS. The fingerprint identification device 100D has similar effects as the fingerprint recognition device 100C, and will not be repeated here.

In summary, the pressing surface of the transparent substrate or the second surface of the light guiding element of the fingerprint identification device of the present invention is an irregular rough surface. By the non-periodic structure distribution of the rough surface, after the light beam reflected by the finger passes through the rough surface, the light beam does not carry the image information corresponding to the periodic structure and interferes with the fingerprint information originally carried by the light beam. Thereby, the image sensing component can obtain a fingerprint image of a clear finger and contribute to fingerprint recognition.

In the light guiding element of the fingerprint identification device of another embodiment of the present invention, a plurality of scattering particles are disposed. After passing through the light guiding element, the light beam reflected by the finger is scattered by the scattering particles in the light guiding element without carrying the image information corresponding to the periodic structure and interfering with the fingerprint information originally carried by the light beam. Thereby, the image sensing component can obtain a fingerprint image of a clear finger, which is helpful for fingerprint recognition.

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

100, 100A, 100C, 100B, 100D‧‧‧ fingerprint identification device

110, 110A, 110B, 110C, 110D‧‧‧ light guiding components

110a‧‧‧ first surface

110b‧‧‧ second surface

110c‧‧‧ side

112‧‧‧coupled light department

114‧‧‧Light Guide

116‧‧‧Connecting Department

120, 120A‧‧‧ Transparent substrate

122‧‧‧ upper surface

122a‧‧‧ Pressing surface

122b‧‧‧Non-pressing surface

130‧‧‧Light source

140‧‧‧Image sensing components

150‧‧‧scattering particles

F‧‧‧ finger

MS‧‧‧Microstructure

L‧‧‧beam

T1, T2, T3‧‧‧ thickness

1 is a cross-sectional view of a fingerprint identification device in accordance with an embodiment of the present invention. 2 is a cross-sectional view of a fingerprint identification device in accordance with another embodiment of the present invention. 3 is a cross-sectional view of a fingerprint identification device according to still another embodiment of the present invention. 4 is a cross-sectional view showing a fingerprint identification device according to still another embodiment of the present invention. FIG. 5 is a cross-sectional view of a fingerprint identification device according to an embodiment of the present invention.

Claims (10)

A fingerprint recognition device comprising: a light guiding element having a first surface, a second surface opposite to the first surface, and a side surface connected between the first surface and the second surface; a transparent base a material formed on the first surface of the light guiding element and having a pressing surface for pressing by a finger; a light source for emitting a light beam and disposed beside the side of the light guiding element; and an image sense The measuring component is disposed relative to the second surface of the light guiding component, wherein the light beam sequentially enters the light guiding component from the side surface of the light guiding component, and the pressing surface passing through the transparent substrate is located on the pressing surface The first finger on the transparent substrate, the first surface and the second surface of the light guiding element are transmitted to the image sensing element; the pressing surface of the transparent substrate or the light guiding component The second surface is an irregular rough surface. The fingerprint identification device of claim 1, wherein the pressing surface of the transparent substrate is the irregular rough surface, and the roughness of the pressing surface of the transparent substrate is greater than the light guiding element The roughness of the second surface. The fingerprint identification device of claim 1, wherein the second surface of the light guiding element is the irregular rough surface, and the second surface of the light guiding element has a roughness greater than the transparent substrate. The roughness of the pressing surface. The fingerprint identification device of claim 1, wherein the second surface of the light guiding element has a plurality of microstructures, and the pressing surface of the transparent substrate is the irregular rough surface, and the guiding light The roughness of the second surface of the component is greater than the roughness of the pressing surface of the transparent substrate. The fingerprint identification device of claim 4, wherein the microstructures of the second surface of the light guiding element are regularly arranged. The fingerprint identification device of claim 4, wherein the second surface of the light guiding element has a roughness greater than 0.010 micrometers and less than 10 micrometers. The fingerprint identification device of any one of claims 1 to 6, wherein the irregular rough surface has a roughness greater than 0.001 micrometers and less than 1 micrometer. A fingerprint identification device comprising: a light guiding element having a first surface, a second surface opposite to the first surface, and a side surface connected between the first surface and the second surface; a transparent substrate disposed on the first surface of the light guiding element and having a pressing surface for pressing by a finger; a light source for emitting a light beam and disposed on the a side of the side of the light guiding element; and an image sensing element disposed relative to the second surface of the light guiding element, wherein the light beam sequentially enters the light guiding element from the side of the light guiding element The scattering particles are scattered toward the pressing surface of the transparent substrate, reflected by the finger on the pressing surface, passing through the transparent substrate and the light guiding element, and transmitted to the image sensing element. The fingerprint identification device of claim 8, wherein the second surface of the light guiding element has a plurality of microstructures, wherein a roughness of the second surface of the light guiding element is greater than that of the transparent substrate The roughness of the pressing surface and the roughness of the first surface of the light guiding element. The fingerprint identification device of claim 9, wherein the second surface of the light guiding element has a roughness greater than 0.010 micrometers and less than 10 micrometers.