Finger vein recognition device based on screen printing correction LSC

Abstract

A finger vein recognition device based on screen printing correction LSC relates to the field of biological recognition and comprises a shell, a near-infrared lamp band composed of near-infrared lamp beads, a near-infrared optical filter, screen printing and a camera device. The shell is provided with a vein collection window, the near-infrared lamp strip is installed on the side edge of the vein collection window, and near-infrared light emitted by the near-infrared lamp strip can enter the vein collection window after transmitting a target object; the near-infrared light filter covers the upper side of the near-infrared light strip; the silk screen is arranged on one side, close to the vein acquisition window, of the near-infrared optical filter; the camera device is installed in the shell and used for receiving light rays entering the vein collection window for induction imaging. According to the equipment, LSC correction is realized through a physical scheme, an image processing algorithm does not need to be adopted, LSC correction on each module is avoided, the production efficiency is improved, the optimization time of the image is not increased, and the finger vein recognition speed is further improved.

Description

Technical Field

[0001] This utility model relates to the field of biometric technology, and in particular to a finger vein recognition device based on screen-printed corrected LSC. Background Technology

[0002] Due to the physical characteristics of lenses, the amount of light transmitted gradually decreases from the center to the edges. This results in the original finger vein images acquired by finger vein recognition devices typically exhibiting higher brightness in the central pixels, with brightness decreasing towards the edges. Current industry solutions employ image processing algorithms to perform Lens Shading Correction (LSC) on the original finger vein images, raising the grayscale level around the edges to match the center and improve image quality. Traditional solutions require LSC correction for each module, increasing production time and reducing efficiency. Furthermore, using concentric circle and grid methods in the ISP for lens shading correction further increases image optimization time, ultimately impacting finger vein recognition speed. Utility Model Content

[0003] This invention provides a finger vein recognition device based on screen printing-corrected LSC. The device covers a near-infrared filter above a near-infrared light strip with screen printing, achieving LSC correction through a physical method. It does not require image processing algorithms, thus avoiding LSC correction for each module and not increasing image optimization time.

[0004] To achieve the above objectives, this utility model provides the following solution:

[0005] This utility model relates to a finger vein recognition device based on screen printing correction LSC, comprising: a housing, a near-infrared LED strip composed of near-infrared LED beads, a near-infrared filter, screen printing, and a camera device;

[0006] The housing is provided with a vein acquisition window, and the near-infrared light strip is installed on the side of the vein acquisition window. The near-infrared light emitted by the near-infrared light strip can penetrate the target object and enter the vein acquisition window.

[0007] The near-infrared filter covers the upper side of the near-infrared light strip;

[0008] The screen printing is located on the side of the near-infrared filter closest to the vein acquisition window;

[0009] The camera device is installed inside the housing and is used to receive light-sensing images entering the vein acquisition window.

[0010] Preferably, the screen printing is applied to the side of the near-infrared filter facing the near-infrared lamp strip.

[0011] Preferably, the length of the silkscreen is equal to the length of the near-infrared filter, and the width of the silkscreen is inversely proportional to the distance between the corresponding near-infrared LED bead and the center of the vein acquisition window.

[0012] Preferably, the screen printing is made of an opaque material to block some of the near-infrared light emitted by the near-infrared light strip from penetrating the target object.

[0013] Preferably, the screen printing is ink, which is sprayed onto the near-infrared filter.

[0014] Preferably, the screen printing is an opaque sticker, which is affixed to the near-infrared filter.

[0015] Preferably, the housing has a concave structure, and the vein collection window is disposed in the concave structure.

[0016] Preferably, the near-infrared light strip is installed on the upper side of the vein collection window, and the near-infrared light strip is oriented towards the target object.

[0017] Preferably, the vein acquisition window is flush with the housing, and the near-infrared light strip is installed below the housing and is oriented towards the target object.

[0018] Preferably, the finger vein recognition device further includes a control circuit board installed inside the housing, the control circuit board being communicatively connected to the near-infrared light strip and the camera device.

[0019] Compared to existing technologies, the finger vein recognition device based on screen printing-corrected LSC of this invention achieves LSC correction through a physical method by covering a near-infrared filter above a near-infrared light strip with screen printing. This eliminates the need for image processing algorithms, avoiding the need for LSC correction for each module, thus improving production efficiency and reducing image optimization time, thereby increasing finger vein recognition speed. Furthermore, using screen printing for LSC correction has lower hardware requirements, allowing it to be applied to finger vein recognition devices with different hardware models, increasing the versatility of the device. Attached Figure Description

[0020] Appendix Figure 1 A schematic diagram of adding finger vein images captured before screen printing to a vein recognition device;

[0021] Appendix Figure 2 This utility model relates to a schematic diagram of the structure of a finger vein recognition device based on screen-printed corrected LSC;

[0022] Appendix Figure 3 This is a schematic diagram of the silkscreen printing on the infrared filter involved in this utility model;

[0023] Appendix Figure 4This is a schematic diagram of another finger vein recognition device based on screen-printed corrected LSC in this utility model;

[0024] Explanation of annotations in the diagram:

[0025] 1-Housing; 2-Near-infrared LED strip; 3-Near-infrared filter; 4-Silk screen printing; 5-Camera device; 6-Vein acquisition window; 7-Recessed structure; 8-Control circuit board. Detailed Implementation

[0026] To make the objectives, technical solutions and advantages of this utility model clearer, the present utility model will be specifically described below in conjunction with the embodiments and accompanying drawings, but the protection scope of this utility model is not limited thereto.

[0027] Finger vein recognition technology is a biometric identification technology that uses images of veins in a person's finger to identify the individual. The first step in finger vein recognition technology is to acquire an image of the user's finger veins using a finger vein recognition device. Depending on the application scenario, the arrangement and lighting method of the near-infrared LED strips in the finger vein recognition device vary. In side-lit finger vein recognition devices, as described in the background section, due to the physical characteristics of the lens, the acquired image typically has high brightness in the center pixels and low brightness in the surrounding pixels, resulting in an image formed by light hitting the sides of the finger, as shown in the attached image. Figure 1 The uneven grayscale shown leads to an increase in overexposed areas and a decrease in the effective area, affecting the recognition rate of finger veins. Example 1

[0028] To solve the above technical problems, refer to the appendix. Figure 2 As shown, this utility model provides a finger vein recognition device based on screen-printed corrected LSC, including: a housing 1, a near-infrared light strip 2 composed of near-infrared LED beads, a near-infrared filter 3, screen printing 4, and a camera device 5; a vein acquisition window 6 is provided on the housing 1, the near-infrared light strip 2 is installed on the side of the vein acquisition window 6, and the near-infrared light emitted by the near-infrared light strip 2 can penetrate the target object and enter the vein acquisition window 6; the near-infrared filter 3 covers the upper side of the near-infrared light strip 2; the screen printing 4 is provided on the side of the near-infrared filter 3 near the vein acquisition window 6; the camera device 5 is installed inside the housing 1 and is used to receive the light entering the vein acquisition window 6 for imaging.

[0029] In one embodiment, the screen printing 4 is disposed on the side of the near-infrared filter 3 facing the near-infrared lamp strip 2, which can prevent the screen printing from being worn during use and affecting the performance.

[0030] In one embodiment, the housing 1 has a concave structure 7, and the vein acquisition window 6 is disposed in the concave structure 7; the near-infrared light strip 2 is installed on the upper side of the vein acquisition window 6, and the near-infrared light strip 2 is oriented towards the target object. In one case, the near-infrared light strip 2 is installed only on the upper side of the vein acquisition window 6, and in another case, the near-infrared light strip 2 is installed only on the upper sides of the vein acquisition window 6; there is no limitation on this.

[0031] In one embodiment, the finger vein recognition device further includes a control circuit board 8 installed inside the housing 1, which is communicatively connected to the near-infrared light strip 2 and the camera device 5. When a user's finger is placed in the concave structure, the control circuit board 8 controls the near-infrared light strip 2 to emit near-infrared light and controls the camera device 5 to capture the user's finger vein image.

[0032] The working principle of the finger vein recognition device is as follows: the target object, i.e. the user's finger, is placed in the concave structure 7. The near-infrared light emitted by the near-infrared light strip 2 passes through the user's finger and enters the vein acquisition window 6, where it is received and imaged by the camera device 5.

[0033] In one embodiment, the silkscreen 4 is made of an opaque material to block some of the near-infrared light emitted by the near-infrared light strip 2 from penetrating the target object. (See attached diagram.) Figure 3 As shown in the shapes of the silkscreen 4 and the near-infrared filter 3, the length of the silkscreen 4 is equal to the length of the near-infrared filter 3, and the width of the silkscreen 4 is inversely proportional to the distance between the corresponding near-infrared LED and the center of the vein acquisition window 6. If the near-infrared LED is closer to the center of the vein acquisition window 6, more light will enter the vein acquisition window 6 after passing through the user's finger. Therefore, setting the width of the silkscreen to be wider can reduce the amount of light entering, thereby making the acquired finger vein image have uniform brightness.

[0034] In one embodiment, screen printing 4 is ink, which is sprayed onto the near-infrared filter 3.

[0035] In one embodiment, the silkscreen 4 is an opaque sticker that is affixed to the near-infrared filter 3.

[0036] The principle of screen printing is as follows: the target object, i.e. the user's finger, is placed in the concave structure 7. The near-infrared light emitted by the near-infrared light strip 2 passes through the screen printing. Some of the light is blocked by the screen printing, and the remaining light passes through the user's finger and enters the vein acquisition window 6, where it is received and imaged by the camera device 5. Example 2

[0037] Based on Example 1, refer to Appendix Figure 4As shown, the vein acquisition window 6 of the finger vein recognition device is flush with the housing 1. The near-infrared light strip 2 is installed below the housing 1 and is oriented towards the target object. The screen printing 4 is located on the side of the near-infrared filter 3 near the vein acquisition window 6. When the target object, i.e., the user's finger, is placed at the vein acquisition window 6, the near-infrared light emitted by the near-infrared light strip 2 passes through the screen printing. Some of the light is blocked by the screen printing, and the remaining light passes through the user's finger and enters the vein acquisition window 6, where it is received and imaged by the camera device 5.

[0038] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A finger vein recognition device based on screen-printed corrected LSC, characterized in that, include: Housing, near-infrared LED strip composed of near-infrared LED beads, near-infrared filter, screen printing, camera device; The housing is provided with a vein acquisition window, and the near-infrared light strip is installed on the side of the vein acquisition window. The near-infrared light emitted by the near-infrared light strip can penetrate the target object and enter the vein acquisition window. The near-infrared filter covers the upper side of the near-infrared lamp strip; The screen printing is located on the side of the near-infrared filter closest to the vein acquisition window; The camera device is installed inside the housing and is used to receive light-sensing images entering the vein acquisition window.

2. The finger vein recognition device based on screen-printed corrected LSC according to claim 1, characterized in that, The screen printing is applied to the side of the near-infrared filter facing the near-infrared lamp strip.

3. The finger vein recognition device based on screen-printed corrected LSC according to claim 1, characterized in that, The length of the silkscreen is equal to the length of the near-infrared filter, and the width of the silkscreen is inversely proportional to the distance between the corresponding near-infrared LED bead and the center of the vein acquisition window.

4. The finger vein recognition device based on screen-printed corrected LSC according to claim 1, characterized in that, The screen printing is made of an opaque material, used to block some of the near-infrared light emitted by the near-infrared light strip from penetrating the target object.

5. The finger vein recognition device based on screen-printed corrected LSC according to claim 4, characterized in that, The screen printing is done with ink, which is sprayed onto the near-infrared filter.

6. The finger vein recognition device based on screen-printed corrected LSC according to claim 4, characterized in that, The screen printing is an opaque sticker, which is affixed to the near-infrared filter.

7. The finger vein recognition device based on screen-printed corrected LSC according to claim 1, characterized in that, The housing has a concave structure, and the vein collection window is disposed in the concave structure.

8. The finger vein recognition device based on screen-printed corrected LSC according to claim 7, characterized in that, The near-infrared light strip is installed on the upper side of the vein collection window, and the near-infrared light strip is oriented towards the target object.

9. The finger vein recognition device based on screen-printed corrected LSC according to claim 1, characterized in that, The vein acquisition window is flush with the housing, and the near-infrared light strip is installed below the housing and is oriented towards the target object.

10. The finger vein recognition device based on screen-printed corrected LSC according to claim 1, characterized in that, The finger vein recognition device also includes a control circuit board installed inside the housing, which is communicatively connected to the near-infrared light strip and the camera device.

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