TWM606026U - Fingerprint identification device and electronic device - Google Patents

Abstract

A fingerprint identification device and an electronic device. The fingerprint recognition device includes a sensor. The sensor is arranged below the glass screen. The sensor captures the first image when a finger does not touch the glass screen, and captures the second image when the finger is pressed against the glass screen. The electronic device compares a first fingerprint ridge image and a first fingerprint valley image in the first image to obtain a first comparison result, compares a second fingerprint ridge image and a second fingerprint valley image in the second image to obtain a second comparison result and judges whether the finger is a human finger based on the first comparison result and the second comparison result.

Description

Fingerprint identification device and electronic device

The present invention relates to a fingerprint identification device and an electronic device, and particularly relates to a fingerprint identification device and an electronic device that can identify whether a finger image is a human finger.

In recent years, biometric sensing technology has been widely used in various electronic devices or terminal devices to provide various identity login or identity verification functions. In particular, fingerprint sensing and palmprint sensing are currently common sensing solutions. Generally speaking, the user can press a finger on the image sensor so that the image sensor obtains a fingerprint image for subsequent identification or verification operations. However, because hackers may attempt to pass the verification by printing fingerprints, how to determine whether the fingerprints are from surface prints is one of the important research directions in this field.

This new creation provides a fingerprint recognition device and an electronic device that can recognize whether a finger image is a human finger.

The fingerprint identification device created by the new model is suitable for enabling the processor to identify the finger through the glass screen. The fingerprint recognition device includes a sensor. The sensor is coupled to the processor. The sensor is arranged below the surface. The sensor captures the first image when the finger is not touching the glass screen, and captures the second image when the finger is pressed against the glass screen. The processor is coupled to the sensor. The processor compares the first fingerprint ridge image and the first fingerprint valley image in the first image to obtain a first comparison result, and compares the second fingerprint ridge image and the second fingerprint valley image in the second image to obtain a second comparison result, And the judging unit judges whether the finger is a human finger based on the first comparison result and the second comparison result.

The electronic device created by the present invention includes a glass screen, the aforementioned fingerprint identification device and a processor. The fingerprint recognition device is configured to capture a first image when the finger is not touching the glass screen through the glass screen, and capture a second image when the finger is pressed against the glass screen. The processor is coupled to the fingerprint identification device. The processor is configured to compare a first fingerprint ridge image and a first fingerprint valley image in the first image to obtain a first comparison result, and compare a second fingerprint ridge image and a second fingerprint valley image in the second image To obtain a second comparison result, and determine whether the finger is a human finger based on the first comparison result and the second comparison result.

Based on the above, the new creation will capture the first image when the finger is not touching the glass screen, and capture the second image when the finger is pressed against the glass screen. The fingerprint recognition device obtains a first comparison result according to the first image, and obtains a second comparison result according to the second image. The new creation is also based on the first comparison result and the second comparison result Determine whether the finger is a human finger. Therefore, the new creation can perform fingerprint recognition only after judging that the finger is a human finger, thereby improving the security of fingerprint recognition.

In order to make the above-mentioned features and advantages of the new creation more obvious and understandable, the following embodiments are specially cited, and the accompanying drawings are described in detail as follows.

100: electronic device

110: glass screen

120: Fingerprint recognition device

121: Sensor

130: processor

300A, 300B: Comparison result diagram

CR1: First comparison result

CR2: Second comparison result

FGR: Finger

FO: fake finger

IM1, FM1: the first image

IM2, FM2: Second image

L1: Light signal of fingerprint ridge

L1_1, L1_2: light signal of fingerprint ridge

L2: Light Signal of Fingerprint Valley

PL1, PL2: surface

S110, S120, S130, S131, S132, S133, S134: steps

FIG. 1 is a schematic diagram of an electronic device according to an embodiment of the present invention.

Fig. 2 is a flowchart of a fingerprint identification method according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of generating a first image according to an embodiment of the present invention.

4 is a schematic diagram of generating a second image according to an embodiment of the creation of the present invention.

FIG. 5 is a schematic diagram of a mechanism in which the second comparison result is different from the first comparison result according to an embodiment of the new creation.

6 is a schematic diagram of a first image and a second image from a fake finger according to an embodiment of the creation of the present invention.

Fig. 7 is a flowchart of a fingerprint identification method according to another embodiment of the present invention.

Please refer to FIG. 1 and FIG. 2 at the same time. FIG. 1 is a schematic diagram of an electronic device according to an embodiment of the invention. Fig. 2 is a flowchart of a fingerprint identification method according to an embodiment of the present invention. In this embodiment, the electronic device 100 includes a glass screen 110, a fingerprint identification device 120, and a processor 130. The glass screen 110 is, for example, at least a part of one of the organic light emitting display and the screen of the organic light emitting display, and the creation of the present invention is not limited thereto. The fingerprint identification device 120 captures the first image when the finger is not touching the glass screen 110 through the glass screen 110, and captures the second image when the finger is pressed against the glass screen 110.

Furthermore, the fingerprint identification device 120 includes a sensor 121. The sensor 121 is arranged below the surface of the glass screen 110. In an embodiment, the sensor 121 may be placed in contact with the surface PL1 of the glass screen 110, but the creation of the present invention is not limited to this. In some embodiments, the sensor 121 may not be in contact with the surface PL1. In this embodiment, in step S110, the sensor 121 captures the first image IM1 when the finger FGR does not touch the glass screen 110 (for example, the finger FGR approaches the glass screen 110 and does not touch the glass screen 110), and The second image IM2 when the finger FGR is pressed onto the glass screen 110 is captured. For example, the sensor 121 captures the first image IM1 where the finger FGR is not in contact with the glass screen 110 by a non-contact sensing method (eg, optical sensing method). When the finger FGR presses the surface PL2, the sensor 121 senses a large-area contact between the finger FGR and the glass screen 110, and the sensor 121 captures the second image IM2 of the finger FGR accordingly.

In this embodiment, the processor 130 is coupled to the sensor 121. In steps In S120, the processor 130 compares the first fingerprint ridge image and the first fingerprint valley image in the first image IM1 to obtain a first comparison result CR1, and compares the second fingerprint ridge image and the second fingerprint valley image in the second image IM2. Image to obtain the second comparison result CR2. In step S130, the processor 130 determines whether the finger FGR is a human finger based on the first comparison result CR1 and the second comparison result CR2. In this embodiment, the processor 130 determines whether the finger FGR is a human finger based on whether the first comparison result CR1 and the second comparison result CR2 are different, for example, whether the fingerprint to be verified comes from flat printing. For example, when the first comparison result CR1 and the second comparison result CR2 are determined to be different, the processor 130 determines that the finger FGR is a human finger. When the first comparison result CR1 and the second comparison result CR2 are determined to be the same, the processor 130 will determine that the finger FGR is not a human finger. In this way, the security of fingerprint recognition can be improved. In this embodiment, the processor 130 is, for example, a central processing unit (CPU), or other programmable general-purpose or special-purpose microprocessors (Microprocessors), digital signal processors (Digital Signal Processors). , DSP), programmable controller, application specific integrated circuit (Application Specific Integrated Circuits, ASIC), programmable logic device (Programmable Logic Device, PLD) or other similar devices or a combination of these devices, which can be loaded And execute the computer program. In some embodiments, the processor 130 may be provided inside the fingerprint identification device 120. The configuration of the processor created by the present invention is not limited to this embodiment.

Please refer to FIG. 1, FIG. 3, and FIG. 4 at the same time. FIG. 3 is a schematic diagram of generating a first image according to an embodiment of the present invention. Figure 4 is based on the invention A schematic diagram of the generation of the second image shown in an embodiment. Taking a human finger as an example, in this embodiment, when the finger FGR has not reached the glass screen 110, the sensor 121 captures the first image IM1 of the finger FGR (as shown in FIG. 3). The first image IM1 is an image of the finger FGR that has not touched the glass screen 110. The second image IM2 is an image when the finger FGR touches the glass screen 110. The signal characteristic of the first image IM1 is different from the signal characteristic of the second image IM2. Therefore, the processor 130 can identify whether the finger FGR is a human finger or a flat fingerprint after printing according to the difference between the signal characteristic of the first image IM1 and the signal characteristic of the second image IM2. In this embodiment, the signal characteristic of the first image IM1 may be the signal strength relationship between the first fingerprint ridge image and the first fingerprint valley image. The signal characteristic of the second image IM2 may be the signal strength relationship between the second fingerprint ridge image and the second fingerprint valley image. In this embodiment, in the first image IM1, the signal strength of the first fingerprint ridge image is greater than the signal strength of the first fingerprint valley image. Therefore, in this embodiment, the first comparison result CR1 corresponding to the finger shows that the signal strength of the first fingerprint ridge image is greater than the signal strength of the first fingerprint valley image.

In this embodiment, when the finger FGR presses the surface PL2, the sensor 121 captures the second image IM2 of the finger FGR (as shown in FIG. 4). The second image IM2 reflects the contact portion of the glass screen 110 pressed by the finger FGR. Different from the first image IM1, after the finger FGR presses the glass screen 110, since the refractive index of the finger FGR and the glass screen 110 are similar, most of the light passing through the fingerprint ridge and the surface PL1 of the glass screen 110 will penetrate the fingerprint ridge. The light signal reflected by the fingerprint ridge is relatively small. Therefore, in the second image IM2, the signal strength of the second fingerprint ridge image will be less than that of the second fingerprint The signal strength of the valley image. In this embodiment, the second comparison result CR2 corresponding to the finger shows that the signal intensity of the second fingerprint ridge image is lower than the signal intensity of the second fingerprint valley image. It can be seen that the first comparison result CR1 and the second comparison result CR2 corresponding to the finger are opposite.

Therefore, when the first comparison result CR1 shows that the signal strength of the first fingerprint ridge image is greater than the signal strength of the first fingerprint valley image, and the second comparison result CR2 shows that the signal strength of the second fingerprint ridge image is less than the signal strength of the second fingerprint valley image When the intensity is high, the processor 130 can determine that the finger FGR is a human finger.

On the other hand, when the first comparison result CR1 is the same as the second comparison result CR2, for example, the signal strength of the first fingerprint ridge image is greater than the signal strength of the first fingerprint valley image, and the signal strength of the second fingerprint ridge image is greater than Based on the signal strength of the second fingerprint valley image, the processor 130 can determine that the finger FGR is not a finger. For example, the fingerprint to be tested may be a flat fingerprint after printing.

Next, the comparison mechanism corresponding to the second comparison result CR2 of a human finger different from the first comparison result CR1 will be further explained. Please refer to FIG. 1 and FIG. 5 at the same time. FIG. 5 is a schematic diagram of a mechanism in which the second comparison result is different from the first comparison result according to an embodiment of the present invention. The fingerprint identification device 120 also includes a light source (not shown) to provide sensing light. The light source provides sensing light to PL2 through the surface PL1. The sensor 121 receives the reflected light from the finger FGR to generate fingerprint ridge images and fingerprint valley images. In the comparison result diagram 300A, when the finger FGR is close to the glass screen 110 but has not touched the glass screen 110, the distance between the fingerprint ridge and the glass screen 110 is small, and the distance between the fingerprint valley and the glass screen 110 Larger. Therefore, compared to the light signal L1 reflected by the fingerprint ridge, the light signal L2 reflected by the fingerprint valley is relatively weak. In this embodiment, the light signal L1 reflected by the fingerprint ridge corresponds to the signal strength of the first fingerprint ridge image, and the light signal L2 reflected by the fingerprint valley corresponds to the signal strength of the first fingerprint valley image. The first comparison result CR1 shows that the signal strength of the first fingerprint ridge image is greater than the signal strength of the first fingerprint valley image.

In the comparison result diagram 300B, when the finger FGR presses the glass screen 110, the fingerprint ridge contacts the glass screen 110. Compared to the comparison result diagram 300A, the fingerprint valley in the comparison result diagram 300B is closer to the glass screen 110. Therefore, in the comparison result diagram 300B, the intensity of the light signal L2 reflected by the fingerprint valley is stronger than the light signal L2 reflected by the fingerprint valley in the comparison result diagram 300A. In addition, since the refractive index of the finger FGR (the refractive index of the skin is about 1.3~1.5) is similar to that of the glass screen 110, part of the optical signal L1_2 will enter the fingerprint ridge through the glass screen 110, and only the part reflected by the fingerprint ridge The optical signal L1_1 will be received by the sensor 121. Therefore, the optical signal L1_1 reflected by the fingerprint ridge received by the sensor 121 is weaker than the optical signal L2 of the fingerprint valley. In this embodiment, the light signal L1_1 reflected by the fingerprint ridge corresponds to the signal strength of the second fingerprint ridge image, and the light signal L2 reflected by the fingerprint valley corresponds to the signal strength of the second fingerprint valley image. The second comparison result CR2 shows that the signal intensity of the second fingerprint ridge image is less than the signal intensity of the second fingerprint valley image.

That is, in this embodiment, the signal strength of the first fingerprint ridge image and the signal strength of the second fingerprint ridge image are related to the refractive index of the glass screen 110 And the distance between the fingerprint ridge of the finger FGR and the glass screen 110. The signal strength of the first fingerprint valley image and the signal strength of the second fingerprint valley image are related to the distance between the fingerprint valley of the finger FGR and the glass screen 110. However, the present invention is not limited to this example.

In some embodiments, the signal characteristic of the first image IM1 may be the brightness value relationship between the first fingerprint ridge image and the first fingerprint valley image. The signal characteristic of the second image IM2 may be the brightness value relationship of the signal strength between the second fingerprint ridge image and the second fingerprint valley image. In the first image IM1, the brightness value of the first fingerprint ridge image is greater than the brightness value of the first fingerprint valley image. The brightness value of the second fingerprint ridge image in the second image IM2 is smaller than the brightness value of the second fingerprint valley image. The details of the above-mentioned brightness value relationship can be sufficiently taught in the embodiments of FIGS. 3 to 5, and will not be repeated.

Please refer to FIG. 1 and FIG. 6. FIG. 6 is a schematic diagram of a first image and a second image from a fake finger according to an embodiment of the present invention. In this embodiment, the fake finger FO is, for example, a printed matter printed with a fingerprint image. When the fake finger FO does not touch the glass screen 110, the sensor 121 captures the first image FM1. When the fake finger FO presses the glass screen 110, the sensor 121 captures the second image FM2. It should be noted that the signal strength of the fingerprint ridge (valley) image in the first image FM1 and the signal strength of the fingerprint ridge (valley) image in the second image FM2 when the fake finger FO has no physical fingerprint fluctuations Roughly the same. The first comparison result CR1 corresponding to the first image FM1 and the second comparison result CR2 corresponding to the second image FM2 will not be changed because of whether the fake finger FO is pressed against the glass screen 110. change. That is, since the first comparison result CR1 is the same as the second comparison result CR2, the processor 130 can determine that the fake finger FO is a flat printed fingerprint.

Please refer to Figure 1 and Figure 7 at the same time. Fig. 7 is a flowchart of a fingerprint identification method according to another embodiment of the present invention. In this embodiment, step S110 and step S120 are the same as those in FIG. 2 and will not be repeated here. In step S131, the processor 130 determines whether the second comparison result CR2 is reversed with respect to the first comparison result CR1. For example, when the first comparison result CR1 shows that the signal strength of the first fingerprint ridge image is greater than the signal strength of the first fingerprint valley image, when the second comparison result CR2 shows that the signal strength of the second fingerprint ridge image is less than the second When the signal strength of the fingerprint valley image is detected, the processor 130 determines that the second comparison result CR2 is reversed with respect to the first comparison result CR1. Conversely, when the second comparison result CR2 shows that the signal intensity of the second fingerprint ridge image is greater than the signal intensity of the second fingerprint valley image, the processor 130 determines that the second comparison result CR2 is not reversed with respect to the first comparison result CR1 .

In this embodiment, if the second comparison result CR2 is determined to be reversed with respect to the first comparison result CR1, the processor 130 will determine in step S132 that the finger FGR is a human finger. Next, the processor 130 will recognize the FGR fingerprint of the finger in step S133.

In some embodiments, step S133 may be performed between step S110 and step S131. In other words, the new creation can also determine whether the finger FGR is a human finger after identifying the fingerprint of the finger FGR. For example, step S133 may be between step S110 and step S120. The processor 130 will perform step S110 After the first image FM1 and the second image FM21 are obtained, the fingerprint of the finger FGR is recognized (step S133). After the fingerprint of the finger FGR is identified by (PASS), the first comparison result CR1 and the second comparison result CR2 are then obtained in step S120. For another example, step S133 may be between step S120 and step S131. After obtaining the first comparison result CR1 and the second comparison result CR2 in step S120, the processor 130 recognizes the fingerprint of the finger FGR (step S133). After the FGR fingerprint of the finger is passed (PASS), the processor 130 will perform the operation of step S131.

Conversely, in step S131, if it is determined that the second comparison result CR2 is not reversed with respect to the first comparison result CR1, the processor 130 will determine in step S134 that the finger FGR is not a human finger. The processor 130 does not recognize the FGR fingerprint of the finger.

In summary, the fingerprint recognition device and electronic device created by the present invention capture the first image when the finger is not touching the glass screen, and capture the second image when the finger is pressed against the glass screen. The fingerprint recognition device obtains a first comparison result according to the first image, and obtains a second comparison result according to the second image. In this way, the fingerprint identification device can identify whether the fingerprint comes from a flat-printed fingerprint based on the first comparison result and the second comparison result, thereby improving the security of fingerprint identification.

Although the creation of this new type has been disclosed in the above embodiments, it is not intended to limit the creation of this new type. Anyone with ordinary knowledge in the technical field can make some changes and changes without departing from the spirit and scope of the new creation. Retouching, therefore, the scope of protection of the creation of the new model shall be subject to the scope of the attached patent application.

100: electronic device

110: glass screen

120: Fingerprint recognition device

121: Sensor

130: processor

PL1, PL2: surface

CR1: First comparison result

CR2: Second comparison result

FGR: Finger

IM1: First image

IM2: Second image

Claims (9)

A fingerprint identification device suitable for electronic devices, wherein: the electronic device includes a processor and a glass screen, and the fingerprint identification device is configured in the electronic device to allow the processor to pair through the glass screen Fingers are recognized, and the fingerprint recognition device includes a sensor, coupled to the processor, arranged below the surface of the glass screen, and capturing the first time when the finger is not touching the glass screen An image, and capture a second image when the finger presses on the glass screen, the processor compares the first fingerprint ridge image and the first fingerprint valley image in the first image to obtain a first comparison result , Comparing the second fingerprint ridge image and the second fingerprint valley image in the second image to obtain a second comparison result, and judging whether the finger is a human finger based on the first comparison result and the second comparison result . The fingerprint identification device according to claim 1, wherein when the first comparison result shows that the signal intensity of the first fingerprint ridge image is greater than the signal intensity of the first fingerprint valley image, and the second comparison result shows When the signal strength of the second fingerprint ridge image is less than the signal strength of the second fingerprint valley image, the processor determines that the finger is a human finger. The fingerprint identification device according to claim 2, wherein: the signal strength of the first fingerprint ridge image and the signal strength of the second fingerprint ridge image are related to the refractive index of the glass screen and the fingerprint of the finger ridge The distance to the glass screen, and the signal strength of the first fingerprint valley image and the signal strength of the second fingerprint valley image are related to the distance between the fingerprint valley of the finger and the glass screen . The fingerprint identification device according to claim 1, wherein when the first comparison result shows that the brightness value of the first fingerprint ridge image is greater than the brightness value of the first fingerprint valley image, and the second comparison result shows When the brightness value of the second fingerprint ridge image is less than the brightness value of the second fingerprint valley image, the processor determines that the finger is a human finger. The fingerprint identification device according to claim 4, wherein: the brightness value of the first fingerprint ridge image and the brightness value of the second fingerprint ridge image are related to the refractive index of the glass screen and the fingerprint of the finger The distance between the ridge and the glass screen, and the brightness value of the first fingerprint valley image and the brightness value of the second fingerprint valley image are related to the fingerprint valley of the finger and the glass screen distance. The fingerprint identification device according to claim 1, wherein when the processor determines that the finger is a human finger, the fingerprint of the finger is identified. The fingerprint recognition device according to claim 1, wherein the processor recognizes the fingerprint of the finger, and after the fingerprint of the finger is recognized, based on the first comparison result and the second comparison result Determine whether the finger is a human finger. The fingerprint identification device according to claim 1, wherein the glass screen is one of an organic light emitting display and a screen of the organic light emitting display. An electronic device, comprising: a glass screen; the fingerprint identification device according to claim 1, configured to capture a first image when a finger is not in contact with the glass screen through the glass screen, and capture the finger A second image when pressed to the glass screen; and a processor, coupled to the fingerprint recognition device, configured to compare the first fingerprint ridge image and the first fingerprint valley image in the first image to obtain the first A comparison result, comparing the second fingerprint ridge image and the second fingerprint valley image in the second image to obtain a second comparison result, and judging whether the finger is based on the first comparison result and the second comparison result For human fingers.

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