Optical fingerprint identification device with anti-counterfeiting function and implementation method thereof

Abstract

The application provides an optical fingerprint identification device with a forgery prevention function and an implementation method thereof. The optical fingerprint identification device comprises: a pixel array, the pixel array comprising black-and-white pixel units for fingerprint identification and color pixel units for forgery prevention; and a microlens array, the microlens array comprising microlenses arranged above the black-and-white pixel units and the color pixel units respectively. By arranging a color filter unit above the microlens corresponding to the color pixel unit, the optical path of the microlens is avoided from being increased, the crosstalk between adjacent pixel units is reduced, the photosensitive sensitivity of the pixel unit is improved, the fingerprint identification performance of the black-and-white pixel unit and the forgery prevention performance of the color pixel unit are ensured, and additional process steps and process costs are avoided, thereby improving the overall performance of the product.

Description

Technical Field

[0001] This invention relates to an optical fingerprint recognition device with anti-counterfeiting function and its implementation method. Background Technology

[0002] Optical fingerprint recognition devices offer users a secure and convenient experience. However, forged fingerprints, created using artificial materials (such as silicone or white glue) to produce fingerprint molds or printed fingerprint images, pose a security risk. Therefore, how to distinguish between genuine and fake fingerprints to improve the security of fingerprint recognition is an urgent problem to be solved.

[0003] Currently, by setting at least two color filter units above some of the pixel units in an optical fingerprint sensor, the fingerprint image captured by these pixel units becomes a color fingerprint image. Since the color fingerprint image has significant differences for different materials, the authenticity of the fingerprint image can be determined based on the color fingerprint image, thereby improving the security of fingerprint recognition.

[0004] See Figure 1 , Figure 2 The existing technology shown includes an optical fingerprint recognition device comprising pixel arrays 100 and 200. Pixel arrays 100 and 200 respectively include conventional pixel units 101 and 201 for fingerprint recognition and anti-counterfeiting pixel units 102 and 202 for anti-counterfeiting. There are no microlenses above the pixel arrays 100 and 200; instead, color filter units 104 and 204 are directly disposed above the anti-counterfeiting pixel units 102 and 202 to achieve the anti-counterfeiting function of the optical fingerprint recognition device. The area above the conventional pixel units can be left empty (e.g., ...). Figure 1 (As shown in the embodiment), it can also be filled with pigment 205 (such as) Figure 2 In the illustrated embodiment, the material and color of pigment 205 can be the same as or different from the pigment used to make the color filter unit 204. However, due to the lack of microlens converging effect, the optical fingerprint recognition devices of these two schemes have relatively low photosensitivity, thus limiting their fingerprint recognition performance.

[0005] To improve photosensitivity, microlenses can be placed above the pixel units. Typically, one pixel unit corresponds to one microlens, or multiple pixel units correspond to one microlens. For fingerprint recognition devices with microlenses above the pixel units, existing technology places the color filter unit between the pixel unit and the microlens, with three specific solutions:

[0006] like Figure 3In the prior art shown, the optical fingerprint recognition device includes a pixel array 300, which includes conventional pixel units 301 for fingerprint recognition and anti-counterfeiting pixel units 302 for anti-counterfeiting. A color filter unit 304 is disposed above the anti-counterfeiting pixel unit 302, and the spaces between the color filter units 304 (i.e., above the conventional pixel units 301) are filled with a transparent material 305. A microlens array 306 is disposed above the color filter units 304 and the transparent material 305. This approach increases the optical path of the microlenses, which can easily lead to increased crosstalk between adjacent pixel units and decreased photosensitivity. Furthermore, after filling with the transparent material, an additional photolithography step is required, increasing the process cost.

[0007] like Figure 4 In the prior art shown, the optical fingerprint recognition device includes a pixel array 400, which includes conventional pixel units 401 for fingerprint recognition and anti-counterfeiting pixel units 402 for anti-counterfeiting. A color filter unit 404 is disposed above the anti-counterfeiting pixel unit 402. The spaces between the color filter units 404 (i.e., above the conventional pixel units 401) are filled with pigment 405. The material and color of the pigment 405 can be the same as or different from the pigment used to make the color filter units 404. A microlens array 406 is disposed above the color filter units 404 and the pigment 405. This approach also increases the optical path of the microlenses, which can easily lead to increased crosstalk between adjacent pixel units and decreased photosensitivity. Although it avoids additional photolithography steps, the pigment covering the conventional pixel units further reduces the photosensitivity of the conventional pixel units.

[0008] like Figure 5 In the prior art shown, the optical fingerprint recognition device includes a pixel array 500, which includes conventional pixel units 501 for fingerprint recognition and anti-counterfeiting pixel units 502 for anti-counterfeiting. A color filter unit 504 is disposed above the anti-counterfeiting pixel unit 502. The areas between and above the color filter units 504 (i.e., above the conventional pixel units 501 and above the anti-counterfeiting pixel units 502) are filled with a relatively thick transparent material 505. A microlens array 506 is disposed above the transparent material 505. Although this avoids additional photolithography steps, this approach significantly increases the optical path of the microlenses, further increasing crosstalk between adjacent pixel units and reducing photosensitivity. Summary of the Invention

[0009] The purpose of this invention is to provide an optical fingerprint recognition device with anti-counterfeiting function and its implementation method, which reduces crosstalk between adjacent pixel units, improves the photosensitivity of pixel units, ensures the fingerprint recognition performance and anti-counterfeiting performance of the optical fingerprint recognition device, and avoids additional process steps and process costs, thereby improving the overall performance of the product.

[0010] Based on the above considerations, one aspect of the present invention provides a method for implementing an optical fingerprint recognition device with anti-counterfeiting function, comprising: providing a pixel array, the pixel array including black and white pixel units for fingerprint recognition and color pixel units for anti-counterfeiting; providing a microlens array, the microlens array including microlenses respectively disposed above the black and white pixel units and the color pixel units; and disposing a color filter unit above the microlens corresponding to the color pixel units to realize the anti-counterfeiting function of the optical fingerprint recognition device.

[0011] Preferably, a color filter unit covers at least a portion of one or more microlenses.

[0012] Preferably, the color filter unit includes filter units of at least two colors.

[0013] Preferably, the color filter unit includes red, green, and blue filter units.

[0014] Preferably, one microlens corresponds to one black-and-white pixel unit or one color pixel unit.

[0015] Preferably, one microlens corresponds to multiple black-and-white pixel units or multiple color pixel units.

[0016] Preferably, the microlens is made of a transparent organic material, oxide, or nitride.

[0017] Preferably, the optical fingerprint recognition device is a camera-type optical fingerprint recognition device or an ultra-thin optical fingerprint recognition device.

[0018] Another aspect of the present invention provides an optical fingerprint recognition device with anti-counterfeiting function, comprising: a pixel array, the pixel array including black and white pixel units for fingerprint recognition and color pixel units for anti-counterfeiting; a microlens array, the microlens array including microlenses respectively disposed above the black and white pixel units and the color pixel units; and a color filter unit disposed above the microlens corresponding to the color pixel units.

[0019] Preferably, a color filter unit covers at least a portion of one or more microlenses.

[0020] Preferably, the color filter unit includes filter units of at least two colors.

[0021] Preferably, the color filter unit includes red, green, and blue filter units.

[0022] Preferably, one microlens corresponds to one black-and-white pixel unit or one color pixel unit.

[0023] Preferably, one microlens corresponds to multiple black-and-white pixel units or multiple color pixel units.

[0024] Preferably, the microlens is made of a transparent organic material, oxide, or nitride.

[0025] Preferably, the optical fingerprint recognition device is a camera-type optical fingerprint recognition device or an ultra-thin optical fingerprint recognition device.

[0026] The optical fingerprint recognition device and its implementation method with anti-counterfeiting function of the present invention avoids increasing the optical path of the microlens by setting the color filter unit above the microlens corresponding to the color pixel unit, reduces crosstalk between adjacent pixel units, improves the photosensitivity of the pixel unit, ensures the fingerprint recognition performance of the black and white pixel unit and the anti-counterfeiting performance of the color pixel unit, and avoids additional process steps and process costs, thereby improving the overall performance of the product. Attached Figure Description

[0027] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments, taken in conjunction with the accompanying drawings.

[0028] Figure 1 This is a schematic diagram of an optical fingerprint recognition device according to Embodiment 1 of the prior art;

[0029] Figure 2 This is a schematic diagram of an optical fingerprint recognition device according to Embodiment 2 of the prior art;

[0030] Figure 3 This is a schematic diagram of an optical fingerprint recognition device according to Embodiment 3 of the prior art;

[0031] Figure 4 This is a schematic diagram of an optical fingerprint recognition device according to Embodiment 4 of the prior art;

[0032] Figure 5 This is a schematic diagram of an optical fingerprint recognition device according to Embodiment 5 of the prior art;

[0033] Figure 6 This is a schematic diagram of an optical fingerprint recognition device according to Embodiment 1 of the present invention;

[0034] Figure 7 This is a schematic diagram of an optical fingerprint recognition device according to Embodiment 2 of the present invention;

[0035] Figure 8 This is a schematic diagram of an optical fingerprint recognition device according to Embodiment 3 of the present invention.

[0036] Throughout the figures, the same or similar reference numerals denote the same or similar devices (modules) or steps. Detailed Implementation

[0037] To address the problems in the prior art, this invention provides an optical fingerprint recognition device and its implementation method with anti-counterfeiting function. By placing the color filter unit above the microlens corresponding to the color pixel unit, the optical path of the microlens is avoided, crosstalk between adjacent pixel units is reduced, the photosensitivity of the pixel unit is improved, the fingerprint recognition performance of the black and white pixel unit and the anti-counterfeiting performance of the color pixel unit are guaranteed, and additional process steps and costs are avoided, thereby improving the overall performance of the product.

[0038] In the following detailed description of preferred embodiments, reference will be made to the accompanying drawings, which form part of this invention. The accompanying drawings illustrate specific embodiments by way of example that enable the implementation of the invention. The exemplary embodiments are not intended to be exhaustive of all embodiments according to the invention. It will be understood that other embodiments may be utilized, and structural or logical modifications may be made, without departing from the scope of the invention. Therefore, the following detailed description is not restrictive, and the scope of the invention is defined by the appended claims.

[0039] Figure 6 This invention illustrates a preferred embodiment of an optical fingerprint recognition device with anti-counterfeiting function. The device includes a pixel array 600 and a microlens array 606. The pixel array 600 includes multiple pixel units 601 and 602, and the microlens array 606 includes microlenses respectively disposed above the pixel units 601 and 602. Preferably, the microlenses are made of transparent organic materials, oxides, or nitrides to provide better light focusing. In the pixel array 600, a portion of the pixel units 602 have color filter units 604 disposed above their corresponding microlenses. The fingerprint images acquired through these pixel units 602 are color fingerprint images. Since these color fingerprint images show significant differences for different materials, the authenticity of the fingerprint image can be determined based on the color fingerprint image, thus realizing the anti-counterfeiting function of the optical fingerprint recognition device. The fingerprint images acquired through the other portion of pixel units 601 without color filter units are black and white fingerprint images, used for conventional fingerprint recognition functions.

[0040] Therefore, the optical fingerprint recognition device with anti-counterfeiting function of the present invention includes: a pixel array 600, the pixel array 600 including a black and white pixel unit 601 for fingerprint recognition and a color pixel unit 602 for anti-counterfeiting; a microlens array 606, the microlens array 606 including microlenses respectively disposed above the black and white pixel unit 601 and the color pixel unit 602; and a color filter unit 604 disposed above the microlens corresponding to the color pixel unit 602.

[0041] Meanwhile, the present invention provides a method for implementing an optical fingerprint recognition device with anti-counterfeiting function, comprising: providing a pixel array 600, the pixel array 600 including a black and white pixel unit 601 for fingerprint recognition and a color pixel unit 602 for anti-counterfeiting; providing a microlens array 606, the microlens array 606 including microlenses respectively disposed above the black and white pixel unit 601 and the color pixel unit 602; and realizing the anti-counterfeiting function of the optical fingerprint recognition device by setting a color filter unit 604 above the microlens corresponding to the color pixel unit 602.

[0042] Because the color filter unit is positioned above the microlens, it avoids increasing the optical path of the microlens, reduces crosstalk between adjacent pixel units, improves the photosensitivity of the pixel units, ensures the fingerprint recognition performance of the black and white pixel units and the anti-counterfeiting performance of the color pixel units, and avoids additional process steps and costs, thus improving the overall performance of the product.

[0043] Preferably, the color filter unit includes filter units of at least two colors, for example... Figure 6 In the illustrated embodiment, the color filter unit 604 includes filter units for three colors: red (R), green (G), and blue (B). In other embodiments not shown, the color filter unit may also include color filter units with other or more color combinations.

[0044] exist Figure 6 In a preferred embodiment shown, a color filter unit 604 covers the entire surface of a microlens 606. Figure 7 In another preferred embodiment shown, a color filter unit 704 may also cover part of the surface of a microlens 706, or cover part or all of the surfaces of multiple microlenses 706, and the relative positions of the color filter unit 704 and the microlens 706 may also be defined according to the actual optical shift design, for example, the center of the color filter unit 704 and the center of the microlens 706 may coincide or be offset to a certain extent.

[0045] exist Figure 6 In a preferred embodiment shown, a microlens 606 corresponds to a monochrome pixel unit 601 or a color pixel unit 602. Figure 8 In another preferred embodiment shown, a microlens 806 may also correspond to multiple black and white pixel units 801 or multiple color pixel units 802.

[0046] Furthermore, the optical fingerprint recognition device and its implementation method of the present invention are particularly applicable to camera-type optical fingerprint recognition devices, and can also be applied to ultra-thin optical fingerprint recognition devices.

[0047] In summary, the optical fingerprint recognition device and its implementation method with anti-counterfeiting function of the present invention avoids increasing the optical path of the microlens by setting the color filter unit above the microlens corresponding to the color pixel unit, reduces crosstalk between adjacent pixel units, improves the photosensitivity of the pixel unit, ensures the fingerprint recognition performance of the black and white pixel unit and the anti-counterfeiting performance of the color pixel unit, and avoids additional process steps and process costs, thereby improving the overall performance of the product.

[0048] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and not restrictive in any way. Furthermore, it is clear that the word "comprising" does not exclude other elements and steps, and the word "a" does not exclude a plurality. Multiple elements recited in the apparatus claims may also be implemented by a single element. The terms "first," "second," etc., are used to denote names and do not indicate any particular order.

Claims

1. An implementation method of an optical fingerprint identification device with anti-counterfeiting function, characterized in that, include: A pixel array is provided, the pixel array including black and white pixel units for fingerprint recognition and color pixel units for anti-counterfeiting; A microlens array is provided, the microlens array comprising microlenses respectively disposed above the black-and-white pixel unit and the color pixel unit; The color filter unit is positioned above the microlens corresponding to the color pixel unit to avoid increasing the optical path of the microlens, thus enabling the anti-counterfeiting function of the optical fingerprint recognition device. 2.The implementation method of the optical fingerprint identification device with anti-fake function according to claim 1, wherein, A color filter unit covers at least a portion of one or more microlenses. 3.The implementation method of the optical fingerprint identification device with anti-fake function according to claim 1, wherein, The color filter unit includes filter units of at least two colors. 4.The implementation method of the optical fingerprint identification device with anti-fake function according to claim 3, characterized in that, The color filter unit includes red, green, and blue filter units. 5.The implementation method of the optical fingerprint identification device with anti-fake function according to claim 1, wherein, One microlens corresponds to one black-and-white pixel unit or one color pixel unit. 6.The implementation method of the optical fingerprint identification device with anti-fake function according to claim 1, wherein, One microlens corresponds to multiple black-and-white pixel units or multiple color pixel units.

7. The method for implementing the optical fingerprint recognition device with anti-counterfeiting function as described in claim 1, characterized in that, The microlens is made of transparent organic materials, oxides, or nitrides. 8.The implementation method of the optical fingerprint identification device with anti-fake function according to claim 1, wherein, The optical fingerprint recognition device is a camera-type optical fingerprint recognition device or an ultra-thin optical fingerprint recognition device.

9. An optical fingerprint recognition device with an anti-counterfeiting function, characterized in that, include: A pixel array, the pixel array comprising black and white pixel units for fingerprint recognition and color pixel units for anti-counterfeiting; A microlens array, comprising microlenses respectively disposed above the monochrome pixel unit and the color pixel unit; and A color filter unit is disposed above the microlens corresponding to the color pixel unit to avoid increasing the optical path of the microlens.

10. The optical fingerprint recognition device with anti-counterfeiting function as described in claim 9, characterized in that, A color filter unit covers at least a portion of one or more microlenses.

11. The optical fingerprint recognition device with anti-counterfeiting function as described in claim 9, characterized in that, The color filter unit includes filter units of at least two colors.

12. The optical fingerprint recognition device with anti-counterfeiting function as described in claim 11, characterized in that, The color filter unit includes red, green, and blue filter units.

13. The optical fingerprint recognition device with anti-counterfeiting function as described in claim 9, characterized in that, One microlens corresponds to one black-and-white pixel unit or one color pixel unit.

14. The optical fingerprint recognition device with anti-counterfeiting function as described in claim 9, characterized in that, One microlens corresponds to multiple black-and-white pixel units or multiple color pixel units.

15. The optical fingerprint recognition device with anti-counterfeiting function as described in claim 9, characterized in that, The microlens is made of transparent organic materials, oxides, or nitrides.

16. The optical fingerprint recognition device with anti-counterfeiting function as described in claim 9, characterized in that, The optical fingerprint recognition device is a camera-type optical fingerprint recognition device or an ultra-thin optical fingerprint recognition device.

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