Optical fingerprint sensor module

Abstract

The application provides an optical fingerprint sensor module, comprising: an optical fingerprint sensor having a fingerprint collection surface; a photochromic layer arranged on the fingerprint collection surface, the photochromic layer having a first transmittance under a first light intensity and a second transmittance under a second light intensity, the first light intensity being greater than the second light intensity, and the first transmittance being less than the second transmittance; and an electrochromic component located on one side of the photochromic layer, the electrochromic component having a third transmittance under a third light intensity and a fourth transmittance under a fourth light intensity, the third light intensity being greater than the fourth light intensity, and the third transmittance being less than the fourth transmittance. The arrangement of the electrochromic component and the photochromic layer can control the light intensity at any position of the fingerprint collection surface, reduce the influence of the environmental light intensity on the definition of the fingerprint image collected by the optical fingerprint sensor, and be beneficial to obtaining a clear fingerprint image.

Description

Technical Field

[0001] This invention relates to the field of fingerprint acquisition, and more specifically to an optical fingerprint sensor module. Background Technology

[0002] Fingerprint imaging recognition technology is a commonly used identity verification technology. It first acquires an image of a human fingerprint using an optical fingerprint sensor, then compares it with existing fingerprint information in the system to achieve identity verification. Due to its ease of use, fingerprint imaging recognition technology has been widely applied in various fields. Optical fingerprint sensors primarily utilize the difference in light reflection between the fingerprint valleys and ridges to acquire fingerprint images. This means that the fingerprint images acquired by optical fingerprint sensors are significantly affected by the ambient light intensity; when the ambient light intensity is too high or too low, clear fingerprint information cannot be acquired. Summary of the Invention

[0003] The present invention aims to at least reduce the impact of ambient light intensity on the clarity of fingerprint images acquired by optical fingerprint sensors.

[0004] To address this, the present invention provides an optical fingerprint sensor module, comprising: an optical fingerprint sensor having a fingerprint acquisition surface; a photochromic layer disposed on the fingerprint acquisition surface, the photochromic layer having a first transmittance under a first light intensity and a second transmittance under a second light intensity, wherein the first light intensity is greater than the second light intensity and the first transmittance is less than the second transmittance; and an electrochromic component located on the side of the photochromic layer opposite to the optical fingerprint sensor, the electrochromic component having a third transmittance under a third light intensity and a fourth transmittance under a fourth light intensity, wherein the third light intensity is greater than the fourth light intensity and the third transmittance is less than the fourth transmittance.

[0005] Ambient light illuminating the optical fingerprint sensor module passes through the photochromic layer and electrochromic component and then illuminates the fingerprint collection surface. The optical fingerprint sensor can use this light to collect fingerprints. The transmittance of the photochromic layer and the electrochromic component decreases as the intensity of the ambient light illuminating their surfaces increases, which causes the intensity of the light illuminating the fingerprint collection surface to change accordingly. Specifically, when the ambient light intensity of the optical fingerprint sensor module increases, the transmittance of the entire electrochromic component decreases, thereby reducing the light intensity illuminating the entire fingerprint acquisition surface. Conversely, when the ambient light intensity decreases, the transmittance of the entire electrochromic component increases, thus increasing the light intensity illuminating the entire fingerprint acquisition surface. When the ambient light intensity increases in a local area of ​​the photochromic layer, the transmittance of the photochromic layer in that area automatically decreases, thereby reducing the light intensity illuminating that area. Conversely, when the ambient light intensity decreases in a local area of ​​the photochromic layer, the transmittance of the photochromic layer in that area automatically increases, thereby increasing the light intensity illuminating that area. Therefore, the electrochromic component and photochromic layer can adjust the light intensity illuminating the entire fingerprint acquisition surface and local areas of the fingerprint acquisition surface, reducing the impact of ambient light intensity on the clarity of the fingerprint image acquired by the optical fingerprint sensor, thus contributing to obtaining a clear fingerprint image.

[0006] According to an embodiment of the present invention, when the intensity of ambient light illuminating the photochromic layer is greater than or equal to 4800 lux, the transmittance of the photochromic layer is 10%-15%; when the intensity of ambient light illuminating the photochromic layer is less than or equal to 600 lux, the transmittance of the photochromic layer is 80%-90%. This improves the clarity of the fingerprint image acquired by the optical fingerprint sensor.

[0007] According to an embodiment of the present invention, when the ambient light intensity illuminating the electrochromic component is greater than or equal to 4800 lux, the transmittance of the electrochromic component is 1%-20%; when the ambient light intensity illuminating the electrochromic component is less than or equal to 600 lux, the transmittance of the electrochromic component is 50%-70%. This improves the clarity of the fingerprint image acquired by the optical fingerprint sensor.

[0008] According to an embodiment of the present invention, the intensity of the ambient light illuminating the optical fingerprint sensor module is 0 lux to 100 klux.

[0009] According to an embodiment of the present invention, the optical fingerprint sensor module further includes: a light intensity detection element adapted to detect the light intensity value of the environment in which the optical fingerprint sensor module is located; and a control circuit, wherein the light intensity detection element, the control circuit, and the electrochromic component are electrically connected in sequence, and the control circuit is adapted to adjust the transmittance of the electrochromic component according to the light intensity value of the environment in which the optical fingerprint sensor module is located.

[0010] According to an embodiment of the present invention, the electrochromic component includes a first transparent substrate and a second transparent substrate disposed opposite to each other, and the photochromic layer is located on the side surface of the first transparent substrate facing away from the second transparent substrate.

[0011] According to an embodiment of the present invention, the first transparent substrate comprises glass, and the second transparent substrate comprises glass.

[0012] According to an embodiment of the present invention, the optical fingerprint sensor module further includes a transparent adhesive layer, which is located between the fingerprint acquisition surface and the photochromic layer.

[0013] According to an embodiment of the present invention, the light intensity detection element includes an ambient light sensor. Attached Figure Description

[0014] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of the optical fingerprint sensor module provided in an embodiment of the present invention;

[0016] Explanation of reference numerals in the attached figures:

[0017] 1-Optical fingerprint sensor; 2-Photochromic layer; 3-Electrochromic component. Detailed Implementation

[0018] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0019] As described in the background section, the fingerprint image captured by an optical fingerprint sensor is significantly affected by the ambient light intensity. Specifically, the optical fingerprint sensor has a fingerprint acquisition surface. When the ambient light intensity is too high, the light intensity illuminating the fingerprint acquisition surface is too strong, resulting in the optical fingerprint sensor capturing a pure white image without fingerprint information. Conversely, when the ambient light intensity is too low, the light intensity illuminating the fingerprint acquisition surface is too weak, resulting in an unclear fingerprint image or even no fingerprint image being captured by the optical fingerprint sensor. Similarly, when the ambient light intensity illuminating a local area of ​​the fingerprint acquisition surface of the optical fingerprint sensor is too high or too low, the fingerprint image captured by the optical fingerprint sensor will also be incomplete.

[0020] Based on this, see Figure 1 This embodiment provides an optical fingerprint sensor module, including:

[0021] An optical fingerprint sensor 1, wherein the optical fingerprint sensor 1 has a fingerprint acquisition surface;

[0022] The photochromic layer 2 disposed on the fingerprint collection surface has a first transmittance under a first light intensity and a second transmittance under a second light intensity. The first light intensity is greater than the second light intensity, and the first transmittance is less than the second transmittance.

[0023] An electrochromic component 3 is located on the side of the photochromic layer 2 opposite to the optical fingerprint sensor 1. The electrochromic component 3 has a third transmittance under a third light intensity and a fourth transmittance under a fourth light intensity. The third light intensity is greater than the fourth light intensity, and the third transmittance is less than the fourth transmittance.

[0024] Ambient light illuminating the optical fingerprint sensor module passes through the photochromic layer and electrochromic component and then illuminates the fingerprint collection surface. The optical fingerprint sensor 1 can use this light to collect fingerprints. The transmittance of the photochromic layer 2 and the electrochromic component 3 decreases as the intensity of the ambient light illuminating their surfaces increases, which causes the intensity of the ambient light illuminating the fingerprint collection surface to change accordingly. Specifically, when the ambient light intensity of the optical fingerprint sensor module increases, the transmittance of the entire electrochromic component 3 decreases, thereby reducing the intensity of ambient light illuminating the entire fingerprint acquisition surface. When the ambient light intensity of the optical fingerprint sensor module decreases, the transmittance of the entire electrochromic component 3 increases, thereby increasing the intensity of ambient light illuminating the entire fingerprint acquisition surface. When the ambient light intensity illuminating a local area of ​​the photochromic layer 2 increases, the transmittance of the photochromic layer 2 in that area automatically decreases, thereby reducing the intensity of ambient light illuminating that area. When the ambient light intensity illuminating a local area of ​​the photochromic layer 2 decreases, the transmittance of the photochromic layer 2 in that area automatically increases, thereby increasing the intensity of ambient light illuminating that area. Thus, the electrochromic component 3 and the photochromic layer 2 can adjust the intensity of ambient light illuminating the entire fingerprint acquisition surface and local areas of the fingerprint acquisition surface, reducing the impact of ambient light intensity on the clarity of the fingerprint image acquired by the optical fingerprint sensor 1, which is beneficial for obtaining a clear fingerprint image.

[0025] It should be noted that when the ambient light intensity of the environment surrounding the optical fingerprint sensor module changes, in some specific examples, after adjusting the transmittance of the electrochromic component 3, the intensity of the ambient light illuminating the photochromic layer 2 remains essentially unchanged, thus keeping the transmittance of the photochromic layer 2 essentially unchanged. In other words, the intensity of the ambient light illuminating the fingerprint sensor surface is controlled by adjusting the transmittance of the electrochromic component 3. In other specific examples, after adjusting the transmittance of the electrochromic component 3, the intensity of the ambient light illuminating the photochromic layer 2 remains essentially unchanged. When the ambient light intensity changes slightly, the photochromic layer 2 automatically adjusts its overall transmittance to fine-tune the intensity of the ambient light illuminating the fingerprint sensor surface, thereby controlling the intensity of the ambient light. In other words, the intensity of the ambient light illuminating the fingerprint sensor surface is controlled by adjusting the transmittance of the photochromic layer 2 and the electrochromic component 3. Therefore, by placing the photochromic layer 2 between the fingerprint sensor surface and the electrochromic component 3, the photochromic layer 2 and the electrochromic component 3 can work synergistically. When the ambient light intensity changes in a local area of ​​the fingerprint sensor surface, only the transmittance of the photochromic layer 2 needs to be automatically adjusted; the transmittance of the electrochromic component 3 remains unchanged.

[0026] In this embodiment, when the ambient light intensity illuminating the photochromic layer is greater than or equal to 4800 lux, the transmittance of the photochromic layer is 10%-15%, such as 10%, 11%, 12%, 13%, 14%, or 15%; when the ambient light intensity illuminating the photochromic layer is less than or equal to 600 lux, the transmittance of the photochromic layer is 80%-90%, such as 80%, 82%, 84%, 86%, 88%, or 90%; when the ambient light intensity illuminating the photochromic layer is greater than 600 lux and less than 4800 lux, the transmittance of the photochromic layer is between the above two transmittances, and the transmittance of the photochromic layer decreases as the ambient light intensity illuminating its surface increases. It should be noted that the ambient light intensity illuminating the photochromic layer refers to the ambient light intensity after passing through the electrochromic layer. The photochromic layer can control the intensity of ambient light passing through it within a certain range, thereby improving the clarity of the fingerprint image acquired by the optical fingerprint sensor 1.

[0027] In this embodiment, when the ambient light intensity illuminating the electrochromic component is greater than or equal to 4800 lux, the transmittance of the electrochromic component is 1%-20%, such as 1%, 5%, 10%, 11%, 12%, 13%, 14%, 15%, or 20%, preferably 10%-15%; when the ambient light intensity illuminating the electrochromic component is less than or equal to 600 lux, the transmittance of the electrochromic component is 50%-70%, such as 50%, 55%, 60%, 65%, or 70%, preferably 55%-65%; when the ambient light intensity illuminating the electrochromic component is greater than 600 lux and less than 4800 lux, the transmittance of the electrochromic component is between the above two transmittances, and the transmittance of the electrochromic component decreases as the ambient light intensity illuminating its surface increases. The electrochromic component can control the intensity of ambient light passing through it within a certain range, thereby improving the clarity of the fingerprint image captured by the optical fingerprint sensor 1.

[0028] In this embodiment, the optical fingerprint sensor module further includes: a light intensity detection element (not shown), which is adapted to detect the light intensity value of the environment in which the optical fingerprint sensor module is located; and a control circuit (not shown), wherein the light intensity detection element, the control circuit, and the electrochromic component 3 are electrically connected in sequence, and the control circuit is adapted to adjust the transmittance of the electrochromic component 3 according to the light intensity value of the environment in which the optical fingerprint sensor module is located. Specifically, the light intensity detection element and the optical fingerprint sensor are in the same environment (e.g., the light intensity detection element can be disposed on the side of the electrochromic layer), and the light intensity irradiating the light intensity detection element is the same as the light intensity irradiating the optical fingerprint sensor. Therefore, the light intensity detection element can detect the light intensity value of the environment in which the optical fingerprint sensor module is located. Subsequently, the light intensity value is transmitted to the control circuit, and the control circuit regulates the driving voltage applied to the electrochromic component 3 according to the light intensity value, thereby adjusting the transmittance of the electrochromic component 3. Specifically, the light intensity detection element can be an ambient light sensor.

[0029] It should be noted that if the photochromic layer 2 is located on the side of the electrochromic component 3 away from the fingerprint acquisition surface, when the light intensity of the environment where the optical fingerprint sensor module is located changes, on the one hand, the photochromic layer 2 will automatically adjust its transmittance according to the light intensity of the environment where the optical fingerprint sensor module is located; on the other hand, the control circuit will control the transmittance of the electrochromic component 3 according to the light intensity of the environment where the optical fingerprint sensor module is located. However, the changes in the transmittance of the photochromic layer 2 and the electrochromic component 3 are independent of each other and do not affect each other. This results in an excessively large total change in the transmittance of the photochromic layer 2 and the electrochromic component 3, which is not conducive to obtaining a clear fingerprint image.

[0030] In this embodiment, the ambient light intensity illuminating the optical fingerprint sensor module is 0 lux to 100 klux, such as 0 lux, 10 lux, 100 lux, 500 lux, 600 lux, 700 lux, 800 lux, 900 lux, 1 klux, 2 klux, 3 klux, 4 klux, 4.8 klux, 5 klux, 10 klux, 10 klux, 10 klux, 10 klux, 10 klux, 10 klux, 10 klux, 10 klux, 10 klux, 100 klux. That is, the electrochromic component and photochromic layer enable the optical fingerprint sensor module to collect fingerprints in ambient light within the above-mentioned intensity range, thus broadening the application environment of the optical fingerprint sensor module. The ambient light intensity illuminating the optical fingerprint sensor module is the same as the ambient light intensity illuminating the electrochromic component.

[0031] Specifically, the electrochromic component 3 includes a first transparent substrate and a second transparent substrate disposed opposite to each other, and an electrochromic material layer located between the first transparent substrate and the second transparent substrate. The photochromic layer 2 is located on the surface of the first transparent substrate facing away from the second transparent substrate. Specifically, both the first transparent substrate and the second transparent substrate are, but are not limited to, glass. When both the first transparent substrate and the second transparent substrate are glass, the electrochromic component 3 is electrochromic glass.

[0032] Furthermore, the electrochromic component 3 further includes: a first transparent electrode layer located on the surface of the first transparent substrate facing the second transparent conductive substrate, and a second transparent electrode layer located on the surface of the second transparent substrate facing the first transparent conductive substrate. The electrochromic material layer is located between the first and second transparent electrode layers. The control circuit is electrically connected to the first and second transparent electrode layers and changes the transmittance of the electrochromic material layer by adjusting the driving voltage applied to the electrochromic material layer. Specifically, both the first and second transparent electrode layers can be ITO (indium tin oxide) layers. Furthermore, the electrochromic component 3 may also include other functional layers, such as an ion storage layer and an ion conductor layer. The ion storage layer may be located on the surface of the first transparent electrode layer facing away from the first transparent substrate, and the ion conductor layer may be located on the surface of the ion storage layer facing away from the first transparent substrate.

[0033] In one specific embodiment, the photochromic layer 2 can be formed on one side surface of the electrochromic component 3, for example, on the side surface of the first transparent substrate facing away from the second transparent substrate. In this case, the optical fingerprint sensor module may further include a transparent adhesive layer located between the fingerprint acquisition surface and the photochromic layer 2. This transparent adhesive layer fixes the photochromic layer 2 and the electrochromic component 3 to the fingerprint acquisition surface of the optical fingerprint sensor 1 without affecting their transmittance. The transparent adhesive layer can be made of OCA (Optically Clear Adhesive) optical adhesive.

[0034] The terms "first" and "second" used in this document are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature marked "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0035] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0036] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An optical fingerprint sensor module, characterized by Comprising: an optical fingerprint sensor having a fingerprint collection surface; a photochromic layer disposed on the fingerprint collection surface, the photochromic layer having a first transmittance under a first light intensity and a second transmittance under a second light intensity, the first light intensity being greater than the second light intensity, the first transmittance being less than the second transmittance; an electrochromic assembly located on a side of the photochromic layer facing away from the optical fingerprint sensor, the electrochromic assembly having a third transmittance under a third light intensity and a fourth transmittance under a fourth light intensity, the third light intensity being greater than the fourth light intensity, the third transmittance being less than the fourth transmittance; a light intensity detection element adapted to detect a light intensity value of an environment in which the optical fingerprint sensor module is located; a control circuit, the light intensity detection element, the control circuit and the electrochromic assembly being electrically connected in sequence, the control circuit being adapted to adjust the transmittance of the electrochromic assembly according to the light intensity value of the environment in which the optical fingerprint sensor module is located.

2. The optical fingerprint sensor module according to claim 1, characterized in that When the light intensity of the ambient light irradiating the photochromic layer is greater than or equal to 4800 lux, the transmittance of the photochromic layer is 10%-15%; when the light intensity of the ambient light irradiating the photochromic layer is less than or equal to 600 lux, the transmittance of the photochromic layer is 80%-90%.

3. The optical fingerprint sensor module according to claim 1, characterized in that When the light intensity of the ambient light irradiating the electrochromic assembly is greater than or equal to 4800 lux, the transmittance of the electrochromic assembly is 1%-20%; when the light intensity of the ambient light irradiating the electrochromic assembly is less than or equal to 600 lux, the transmittance of the electrochromic assembly is 50%-70%.

4. The optical fingerprint sensor module according to claim 1, characterized in that The light intensity of the ambient light irradiating the optical fingerprint sensor module is 0 lux-100 klux.

5. The optical fingerprint sensor module according to any one of claims 1-4, wherein The electrochromic assembly comprises a first transparent substrate and a second transparent substrate disposed opposite each other, the photochromic layer being located on a side surface of the first transparent substrate facing away from the second transparent substrate.

6. The optical fingerprint sensor module according to claim 5, characterized in that The first transparent substrate comprises glass, and the second transparent substrate comprises glass.

7. The optical fingerprint sensor module according to claim 5, characterized in that Further comprising: a transparent bonding layer located between the fingerprint collection surface and the photochromic layer.

8. The optical fingerprint sensor module according to claim 1, characterized in that The light intensity detection element comprises an ambient light sensor.

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