TWI835245B - Under-screen fingerprint collection device and information processing device - Google Patents

Abstract

An under-screen fingerprint collection device, which has: a screen with a fingerprint collection area; four light sources around and below the fingerprint collection area of the screen; and a picture capture unit below the fingerprint collection area, wherein the There is an air gap between the image capturing unit and the screen; during operation, one of the light sources emits oblique incident light to illuminate a finger at a pressing position in the fingerprint acquisition area, and the image capturing unit moves in the oblique direction The light rays projected onto the image capturing unit among the reflected rays of incident light produce an image in which the incident angle of the obliquely incident light is greater than a critical angle of total reflection between the screen and the surrounding air.

Description

Under-screen fingerprint collection device and information processing device

The present invention relates to fingerprint collection, and in particular to an under-screen fingerprint collection method that can improve the quality of image collection.

The fingerprint collection methods of smartphones are mainly divided into two methods: push-button and under-screen collection, while under-screen collection is divided into small-area collection and large-area collection.

Please refer to Figure 1, which is a schematic diagram of an existing under-screen fingerprint small-area collection architecture. As shown in Figure 1, the under-screen fingerprint small-area collection architecture includes a screen 10, a light source 11 and an image collection device 12. During operation, a finger 20 presses a small-area collection area of the screen 10, and the light source 11 emits light upward to the small area collection area to generate downward reflected light. These reflected light rays illuminate the image collection device 12 to form an image 12a, where the image 12a includes the fingerprint image of the finger 20 and the The background texture image of other areas of the small area that are not touched by the finger 20 is collected, and the background texture image may interfere with the fingerprint image.

In order to solve the above problems, a novel under-screen fingerprint collection method is urgently needed in this field.

One purpose of the present invention is to disclose an under-screen fingerprint collection solution, which can provide a total reflection condition within the thickness range of the screen by leaving an air gap between a screen and a capture unit, so that a specific When the light from the incident angle range hits the area of the screen that is not touched by a finger, total reflection will occur between the upper and lower surfaces of the screen and will not illuminate the image capture unit, and the light from the specific incident angle range will When the fingerprint of the finger is irradiated, the reflected light will change the angle and pass through the lower surface of the screen to illuminate the image capturing unit, thereby generating a fingerprint image with a high signal-to-noise ratio on the image capturing unit.

Another object of the present invention is to disclose an under-screen fingerprint collection device, which can effectively improve the quality of collected fingerprint images through the above-mentioned under-screen fingerprint collection solution.

Another object of the present invention is to disclose an information processing device that can effectively improve the quality of collected fingerprint images through the above-mentioned under-screen fingerprint collection device, thereby improving the efficiency of fingerprint recognition.

In order to achieve the aforementioned purpose, an under-screen fingerprint collection device is proposed, which has: A screen with a fingerprint collection area; Four light sources located below and around the fingerprint collection area of the screen; and A picture-taking unit below the fingerprint collection area, wherein there is an air gap between the picture-taking unit and the screen; During operation, one of the light sources emits oblique incident light to illuminate a finger at a pressing position in the fingerprint collection area, and the image capturing unit projects the reflected light of the oblique incident light onto the image capturing unit. The light produces an image in which the angle of incidence of the obliquely incident light is greater than a critical angle of total reflection between the screen and the surrounding air.

In one embodiment, each of the light sources has a self-luminous unit and a light guide unit to generate the obliquely incident light.

In a possible embodiment, the self-luminous unit may be an LED unit or an OLED unit.

In one embodiment, the total reflection critical angle is equal to sin ^-1 (1/n), n is the refractive index of the screen, and n is a real number greater than 1.

In one embodiment, the under-screen fingerprint collection device further has a touch sensing unit to detect the pressing position of the finger in the fingerprint collection area, and a light control unit to light up the pressing position according to the pressing position. Whichever light source is closest to the pressing position.

In order to achieve the above object, the present invention further proposes an information processing device, which has a central processing unit and an under-screen fingerprint collection device, wherein the central processing unit is used to communicate with the under-screen fingerprint collection device, and the under-screen fingerprint collection device The fingerprint collection device has: A screen with a fingerprint collection area; Four light sources located below and around the fingerprint collection area of the screen; and A picture-taking unit below the fingerprint collection area, wherein there is an air gap between the picture-taking unit and the screen; During operation, one of the light sources emits oblique incident light to illuminate a finger at a pressing position in the fingerprint collection area, and the image capturing unit projects the reflected light of the oblique incident light onto the image capturing unit. The light produces an image in which the angle of incidence of the obliquely incident light is greater than a critical angle of total reflection between the screen and the surrounding air.

In one embodiment, each of the light sources has a self-luminous unit and a light guide unit to generate the obliquely incident light.

In a possible embodiment, the self-luminous unit may be an LED unit or an OLED unit.

In one embodiment, the total reflection critical angle is equal to sin ^-1 (1/n), n is the refractive index of the screen, and n is a real number greater than 1.

In one embodiment, the under-screen fingerprint collection device further has a touch sensing unit to detect the pressing position of the finger in the fingerprint collection area, and a light control unit to light up the light sources according to the pressing position. The one closest to the pressing position.

In possible embodiments, the information processing device may be a smart handheld device, a portable computer, a wearable device, a vehicle-mounted computer or an access control system.

In order to enable the review committee to further understand the structure, characteristics and purpose of the present invention, drawings and detailed descriptions of preferred embodiments are attached as follows.

The main principle of the present invention is to: leave an air gap between a screen and a picture-taking unit to provide a condition for total reflection within the thickness range of the screen, so that light in a specific incident angle range is reflected before hitting the screen. The area that has not been touched by a finger will produce total reflection between the upper and lower surfaces of the screen and will not illuminate the image capturing unit. When the light in the specific incident angle range illuminates the fingerprint of the finger, the reflected light The angle will be changed to penetrate the lower surface of the screen to illuminate the image capturing unit, thereby generating a fingerprint image with a high signal-to-noise ratio on the image capturing unit. In detail, assuming that the refractive index of the screen is n, and n is a real number greater than 1, the critical angle of total reflection is equal to sin ^-1 (1/n). Taking n=1.5 as an example, the critical angle of total reflection is approximately equal to 41.83 degrees, that is, total reflection will occur when the incident angle is greater than 41.83 degrees.

Please refer to FIGS. 2 and 3 together. FIG. 2 is a schematic top view of an embodiment of the under-screen fingerprint collection device of the present invention; FIG. 3 is a schematic cross-sectional view of the under-screen fingerprint collection device in FIG. 2 . As shown in Figures 2 and 3, an under-screen fingerprint collection device 100 has a screen 110, four light sources 111, 112, 113, and 114 below and around a fingerprint collection area of the screen 110, and below the fingerprint collection area. A picture capturing unit 115, wherein an air gap 116 exists between the picture capturing unit 115 and the screen 110. Accordingly, the surface of the screen 110 under the fingerprint collection area can provide total reflection for incident light with a specific incident angle. Assuming that the refractive index of the screen 110 is n, and n is a real number greater than 1, the critical angle of total reflection is equal to sin ^-1 (1/n). That is, as long as the incident angle of an incident light is greater than sin ^-1 (1/n), the incident light will not pass through the lower surface of the fingerprint collection area.

Please refer to FIG. 4 , which is a schematic diagram of the operation of the under-screen fingerprint collection device 100 to collect a fingerprint of a finger. As shown in FIG. 4 , pressing a finger 20 on the left side of the fingerprint collection area of the screen 110 causes the light source 114 to emit oblique incident light, and the incident angle of the oblique incident light is greater than the critical angle. Accordingly, the light incident on the area not pressed by the finger 20 in the obliquely incident light will be totally reflected between the upper and lower surfaces of the screen 110 without passing through; 20 The light in the pressed area will change the reflection angle and pass downward through the lower surface of the screen 110, thereby forming an image on the image acquisition unit 115. According to this design, the image acquisition unit 115 can obtain a fingerprint image with a high signal-to-noise ratio.

In addition, the present invention may have a touch sensing unit (not shown in the figure) to detect the pressing position of the finger 20, and a light control unit (not shown in the figure) to light four light sources according to the pressing position. The light source closest to the pressing position among 111, 112, 113 and 114. Please refer to FIGS. 5 a to 5 d, which are schematic diagrams of respectively lighting up a closest light source according to four different pressing positions of the finger 20 . As shown in Figure 5a, since the pressing position of the finger 20 is closest to the light source 111, the light source 111 is turned on; as shown in Figure 5b, because the pressing position of the finger 20 is closest to the light source 112, the light source 112 is turned on; as shown in Figure 5c As shown in FIG. 5d, since the pressing position of the finger 20 is closest to the light source 113, the light source 113 is turned on; and as shown in FIG. 5d, since the pressing position of the finger 20 is closest to the light source 114, the light source 114 is turned on.

In addition, the light sources 111, 112, 113, and 114 may each have a self-luminous unit and a light guide unit to generate the oblique incident light, wherein the self-luminous unit may be an LED unit or an OLED unit; and the guide unit may be an LED unit or an OLED unit. The light unit may include a light guide and a pointing light outlet.

According to the above description, the present invention further provides an information processing device. Please refer to FIG. 6 , which illustrates a block diagram of an embodiment of the information processing device of the present invention. As shown in 6, an information processing device 200 has a central processing unit 210 and an under-screen fingerprint collection device 220. The under-screen fingerprint collection device 220 is implemented by the under-screen fingerprint collection device 100, and the central processing unit 210 is implemented by the under-screen fingerprint collection device 100. to communicate with the under-screen fingerprint collection device 220. In addition, the information processing device 200 may be a smart handheld device, a portable computer, a wearable device, a vehicle-mounted computer or an access control system.

Through the design disclosed above, the present invention has the following advantages: 1. The under-screen fingerprint collection method of the present invention can provide a total reflection condition within the thickness range of the screen by leaving an air gap between a screen and a capture unit, so that light in a specific incident angle range can be When the area of the screen that is not touched by a finger is irradiated, total reflection will occur between the upper and lower surfaces of the screen and will not irradiate the image capture unit, and the light in the specific incident angle range will not irradiate the finger before it irradiates the finger. When a fingerprint is scanned, the reflected light changes its angle and passes through the lower surface of the screen to illuminate the image capturing unit, thereby generating a fingerprint image with a high signal-to-noise ratio on the image capturing unit. 2. The under-screen fingerprint collection device of the present invention can effectively improve the quality of the collected fingerprint images through the above-mentioned under-screen fingerprint collection method. 3. The information processing device of the present invention can effectively improve the quality of the collected fingerprint images through the above-mentioned under-screen fingerprint collection device, thereby improving the efficiency of fingerprint recognition.

What is disclosed in this case is a preferred embodiment. Any partial changes or modifications derived from the technical ideas of this case and easily inferred by those familiar with the art will not deviate from the scope of the patent rights of this case.

To sum up, regardless of the purpose, means and effects of this case, it shows that it is completely different from the conventional technology, and that the invention is practical first, and indeed meets the patent requirements for inventions. I sincerely ask the review committee to take a clear look and grant the patent as soon as possible for your benefit. Society is a prayer for the Supreme Being.

10: Screen 11: Light source 12: Image acquisition device 12a: Image 20: Finger 100: Under-screen fingerprint collection device 110: Screen 111: Light source 112: Light source 113: Light source 114: Light source 115: Picture acquisition unit 116: Air gap 200: Information processing device 210: Central processing unit 220: Under-screen fingerprint collection device

Figure 1 is a schematic diagram of an existing small-area fingerprint collection architecture under the screen. FIG. 2 is a schematic top view of an embodiment of the under-screen fingerprint collection device of the present invention. Figure 3 is a schematic cross-sectional view of the under-screen fingerprint collection device in Figure 2. Figure 4 is a schematic diagram of the operation of the under-screen fingerprint collection device in Figure 2 to collect a fingerprint of a finger. Figures 5a to 5d are schematic diagrams of the under-screen fingerprint collection device in Figure 2 lighting up a closest light source respectively according to four different pressing positions of a finger. FIG. 6 is a block diagram of an embodiment of the information processing device of the present invention.

100: Under-screen fingerprint collection device 110: Screen 111: Light source 112: Light source 113: Light source 114: Light source 115: Picture acquisition unit

Claims (7)

An under-screen fingerprint collection device, which has: a screen with a fingerprint collection area; four light sources around and below the fingerprint collection area of the screen, each of the light sources having a self-luminous unit and a light guide unit. Forming an oblique light source; a capture unit below the fingerprint collection area, wherein there is an air gap between the capture unit and the screen; a touch sensing unit for detecting a finger on the fingerprint A pressing position in the collection area; and a light control unit for lighting the corresponding light source among the light sources that is closest to the pressing position according to the pressing position; during operation, the corresponding light source emits an oblique incident light The pressing position of the finger in the fingerprint collection area is irradiated, and the image capturing unit generates an image based on the light reflected by the oblique incident light onto the image capturing unit, wherein the oblique incident light The angle of incidence is greater than a critical angle for total reflection between the screen and the surrounding air. For example, in the under-screen fingerprint collection device described in item 1 of the patent application, the self-luminous unit is an LED unit or an OLED unit. For example, in the under-screen fingerprint collection device described in item 1 of the patent application, the total reflection critical angle is equal to sin ^-1 (1/n), n is the refractive index of the screen, and n is a real number greater than 1. An information processing device, which has a central processing unit and an under-screen fingerprint collection device, wherein the central processing unit is used to communicate with the under-screen fingerprint collection device, and the under-screen fingerprint collection device has: a screen, with a fingerprint collection area; four light sources around and below the fingerprint collection area of the screen, each of the light sources having a self-luminous unit and a light guide unit to form an oblique light source; and a picture acquisition unit below the fingerprint collection area, Among them, there is an air gap between the image capturing unit and the screen; a touch sensing unit used to detect a pressing position of a finger in the fingerprint collecting area; and a light control unit used to press according to the The position lights up the corresponding light source among the light sources that is closest to the pressing position; during operation, the corresponding light source emits an oblique incident light to illuminate the pressing position of the finger in the fingerprint collection area, and the image acquisition The unit generates an image based on the light rays projected onto the image capturing unit from the reflected rays of the obliquely incident light, wherein the incident angle of the obliquely incident light is greater than a total reflection critical angle between the screen and the surrounding air. For example, in the information processing device described in item 4 of the patent application, the self-luminous unit is an LED unit or an OLED unit. For example, in the information processing device described in Item 4 of the patent application, the total reflection critical angle is equal to sin ^-1 (1/n), n is the refractive index of the screen, and n is a real number greater than 1. The information processing device described in item 4 of the patent application is an electronic device selected from a group consisting of a smart handheld device, a portable computer, a wearable device, a vehicle-mounted computer and an access control system. .

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