Finger vein sensor and electronic device

Abstract

The present application discloses a finger vein sensor and an electronic device, belonging to the field of sensor technology. The finger vein sensor includes: a substrate, an infrared light source and an infrared detector. Since the distance between the first light-emitting element in the infrared light source and the sensing area is smaller than the distance between the second light-emitting element in the infrared light source and the sensing area. Therefore, the near-infrared light emitted by the first light-emitting element will travel a shorter distance to the object to be detected in the sensing area. When the object to be detected is the user's finger, the distance between the knuckles in the user's finger and the first light-emitting element is smaller, and the near-infrared light emitted by the first light-emitting element can travel a shorter distance to the knuckles, so that the effect of the vein distribution image at the joint is better. In addition, the thickness of the finger vein sensor is relatively small, which is conducive to integrating the finger vein sensor with other components in an electronic device, so that the electronic device integrated with the finger vein sensor is smaller in size.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a finger vein sensor and electronic equipment. Background Art

[0002] With the rapid development of science and technology, finger vein sensors have achieved rapid development. Finger vein sensors can be used to check the vein characteristics in the finger. Among them, finger veins are composed of the shapes and distribution positions of multiple veins in the finger.

[0003] At present, the finger vein sensor can be composed of a near-infrared light source, a reflector and a macro camera. Among them, the near-infrared light source can emit near-infrared light (wavelength range is 700 nanometers to 1000 nanometers) and shoot it to the user's finger. After that, after the near-infrared light shoots to the user's finger, the hemoglobin in the veins in the user's finger will absorb the near-infrared light shot to the veins in the finger, and the unabsorbed part of the near-infrared light will be slowly reflected to the reflector. Finally, the macro camera will take a picture of the near-infrared light reflected back from the reflector. In this way, the vein distribution map inside the user's finger can be obtained.

[0004] However, the thickness of the finger vein sensor provided with a reflector and a macro camera is usually large, resulting in a larger volume of the electronic device integrated with the finger vein sensor. Summary of the invention

[0005] The embodiment of the present application provides a finger vein sensor and an electronic device. The problem that the finger vein sensor of the prior art is usually thick is solved. The technical solution is as follows:

[0006] In one aspect, a finger vein sensor is provided, wherein the finger vein sensor has a sensing area and a peripheral area around the sensing area, and the finger vein sensor includes:

[0007] substrate;

[0008] at least one infrared light source located on the substrate and distributed in the peripheral area, the infrared light source comprising: at least one first light-emitting element and at least two second light-emitting elements located on both sides of the at least one first light-emitting element, the distance between the first light-emitting element and the sensing area being smaller than the distance between the second light-emitting element and the sensing area;

[0009] And, infrared detectors located on the substrate and distributed in the sensing area, the infrared detectors are configured to: after the object to be detected is located in the sensing area and the at least one infrared light source emits infrared light to the object to be detected, detect the infrared light reflected by the object to be detected.

[0010] Optionally, the infrared light source also includes: a circuit board, the at least one first light-emitting element and the at least two second light-emitting elements are electrically connected to the circuit board, and the distance between a portion of the circuit board used to connect the first light-emitting element and the sensing area is smaller than the distance between a portion of the circuit board used to connect the second light-emitting element and the sensing area.

[0011] Optionally, the circuit board is in a strip shape, having a first strip portion connected to the first light-emitting element, and a second strip portion connected to the second light-emitting element, and a minimum distance between the first strip portion and the sensing area is smaller than a minimum distance between the second strip portion and the sensing area.

[0012] Optionally, the circuit board is an arc-shaped strip circuit board.

[0013] Optionally, in a direction perpendicular to the substrate, a height of the first light-emitting element is smaller than a height of the second light-emitting element.

[0014] Optionally, in the same infrared light source, the number of second light-emitting elements located on one side of the at least one first light-emitting element is the same as the number of second light-emitting elements located on the other side of the at least one first light-emitting element.

[0015] Optionally, a surface of the substrate used for carrying the at least one infrared light source and the infrared detector is an arc-shaped concave surface, and an arc-shaped extension direction of the arc-shaped concave surface intersects with an overall extension direction of the infrared light source.

[0016] Optionally, one surface of the substrate used for carrying the at least one infrared light source and the infrared detector is an arc concave surface, and the curvature of the arc concave surface ranges from 10° to 60°.

[0017] Optionally, an angle between the optical axis of the first light-emitting element and the substrate, and an angle between the optical axis of the second light-emitting element and the substrate are both in the range of 30° to 90°.

[0018] Optionally, the infrared detector comprises: a plurality of driving circuits located on the substrate, a semiconductor layer located on a side of the plurality of driving circuits away from the substrate, and a transparent electrode layer located on a side of the semiconductor layer away from the substrate;

[0019] Wherein, the semiconductor layer is electrically connected to the plurality of driving circuits and the transparent electrode layer respectively.

[0020] Optionally, the semiconductor layer is a planar structure provided in an entire layer, or the semiconductor layer has a plurality of semiconductor blocks corresponding one-to-one to the driving circuits, and the plurality of semiconductor blocks are electrically connected one-to-one to the plurality of driving circuits.

[0021] Optionally, the infrared detector further includes: a packaging layer located on a side of the semiconductor layer facing away from the substrate, and an optical collimation layer located on a side of the packaging layer facing away from the substrate.

[0022] Optionally, the infrared detector further includes: a filter film, the filter film is located between the packaging layer and the optical collimation layer, or the filter film is located on a side of the optical collimation layer away from the substrate, and the filter film is used to filter light except the infrared light.

[0023] Optionally, the finger vein sensor further includes: a sensing electrode located on a side of the infrared detector facing away from the substrate, and a controller electrically connected to the sensing electrode, the at least one infrared light source and the infrared detector, respectively.

[0024] On the other hand, an electronic device is provided, characterized in that it includes: a housing, and a finger vein sensor connected to the housing, and the finger vein sensor is any one of the above-mentioned finger vein sensors.

[0025] The beneficial effects brought by the technical solution provided by the embodiment of the present application include at least:

[0026] A finger vein sensor includes: a substrate, an infrared light source, and an infrared detector. Since the distance between the first light-emitting element in the infrared light source and the sensing area is smaller than the distance between the second light-emitting element in the infrared light source and the sensing area. Therefore, the near-infrared light emitted by the first light-emitting element will be emitted to the object to be detected in the sensing area through a shorter distance. When the object to be detected is a user's finger, the distance between the finger joints in the user's finger and the first light-emitting element is smaller, and the near-infrared light emitted by the first light-emitting element can be emitted to the finger joints through a shorter distance, so that the effect of the vein distribution image at the joint is better. And the distance between the other parts of the user's finger except the finger joints and the second light-emitting element is larger, which can ensure that the vein distribution images of the middle finger joints of the user's finger and the parts except the finger joints in the vein distribution images sensed by the subsequent finger vein sensor through the infrared light source are less different. In addition, the finger vein sensor provided in the embodiment of the present application has a smaller thickness, which is conducive to integrating the finger vein sensor with other components in an electronic device, so that the electronic device integrated with the finger vein sensor is smaller in size. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 is a top view of a finger vein sensor provided in an embodiment of the present application;

[0029] Figure 2 is a working schematic diagram of a finger vein sensor provided in an embodiment of the present application;

[0030] Figure 3 This is an effect diagram of a user's finger placed on a finger vein sensor provided by an embodiment of the present application;

[0031] Figure 4 is a top view of an infrared light source provided in an embodiment of the present application;

[0032] Figure 5 is a top view of another infrared light source provided in an embodiment of the present application;

[0033] Figure 6 is a schematic diagram of the structure of a finger vein sensor provided in an embodiment of the present application;

[0034] Figure 7 is a top view of another finger vein sensor provided in an embodiment of the present application;

[0035] Figure 8 yes Figure 7 The structural schematic diagram at A-A' is shown;

[0036] Fig. 9 is a working schematic diagram of another finger vein sensor provided in an embodiment of the present application;

[0037] Fig.10 is a schematic diagram of a film layer of an infrared detector provided in an embodiment of the present application;

[0038] Fig.11 is a schematic diagram of a film layer of another infrared detector provided in an embodiment of the present application;

[0039] Fig.12 is a schematic diagram of a film layer of a semiconductor layer provided in an embodiment of the present application;

[0040] Fig.13 This is a schematic diagram of a film layer of another infrared detector provided in an embodiment of the present application;

[0041] Fig.14is a schematic structural diagram of an optical collimation layer provided in an embodiment of the present application;

[0042] Fig.15 is a top view of an optical collimation layer provided in an embodiment of the present application;

[0043] Fig.16 is a schematic structural diagram of another optical collimation layer provided in an embodiment of the present application;

[0044] Fig.17 is a schematic diagram of a film layer of another infrared detector provided in an embodiment of the present application;

[0045] Fig.18 is a schematic diagram of the structure of another finger vein sensor provided in an embodiment of the present application;

[0046] Fig.19 This is a rendering of an effect of a user wearing a wearable device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0048] Please refer to Figure 1 , Figure 1 00a and a peripheral area 00b located around the sensing area 00a. The finger vein sensor 000 may include: a substrate 100, at least one infrared light source 200 located on the substrate 100 and distributed in the peripheral area 00b, and an infrared detector 300 located on the substrate 100 and distributed in the sensing area 00a. Figure 1 The finger vein sensor 000 includes two infrared light sources 200 for schematic illustration, and the two infrared light sources 200 are located in the peripheral area 00b on two opposite sides of the sensing area 00a.

[0049] The infrared light source 200 may include: at least one first light emitting element 201 and at least two second light emitting elements 202 located on both sides of the at least one first light emitting element 201, and the distance between the first light emitting element 201 and the sensing area 00a is smaller than the distance between the second light emitting element 202 and the sensing area 00a.

[0050] The infrared detector 300 is configured to detect the infrared light reflected by the object P to be detected after the object P to be detected is located in the sensing area 00a and at least one infrared light source 200 emits infrared light to the object P to be detected. Here, the object P to be detected may be a finger, palm or wrist of the user, and the infrared light emitted by the infrared light source 200 may be near-infrared light with a wavelength ranging from 700 nanometers to 1000 nanometers.

[0051] To see more clearly the working principle of the finger vein sensor 000, please refer to Figure 2 , Figure 2 : is a working schematic diagram of a finger vein sensor provided by an embodiment of the present application. When the object P to be detected (for example, the user's finger) is located in the sensing area 00a of the finger vein sensor 000, since the finger vein Q in the user's finger has reducing hemoglobin, the reducing hemoglobin will absorb the near-infrared light directed to the finger vein Q in the finger, while other tissue structures in the finger will not absorb the near-infrared light. Therefore, part of the near-infrared light directed to the finger that is not absorbed will be reflected by other tissue structures in the finger, so that the infrared detector 300 can receive this part of the near-infrared light. In this way, the finger vein sensor 000 can obtain the vein distribution image inside the user's finger through the infrared detector 300.

[0052] In the embodiment of the present application, since the distance h1 between the first light emitting element 201 in each infrared light source 200 and the sensing area 00a is smaller than the distance h2 between the second light emitting element 202 and the sensing area 00a, the near infrared light emitted from the first light emitting element 201 will travel a shorter distance to the object to be detected P in the sensing area 00a.

[0053] In this case, when the object P to be detected is a finger of the user, as shown in FIG. Figure 3 As shown, Figure 3 This is a rendering of a user's finger placed on a finger vein sensor provided by an embodiment of the present application, in which the knuckle K in the user's finger is adjacent to the first light-emitting element 201, and the other parts of the user's finger except the knuckle K are adjacent to the second light-emitting element 202. Since the tissue structure at the knuckle K in the user's finger is more complex than the tissue structure of the other parts except the knuckle K. Therefore, it is necessary to ensure that the near-infrared light directed to the knuckle K is more than the near-infrared light directed to the other parts except the knuckle K. To this end, when the distance h1 between the first light-emitting element 201 and the sensing area 00a in each infrared light source 200 is smaller than the distance h2 between the second light-emitting element 202 and the sensing area 00a, the distance between the knuckle K in the user's finger and the first light-emitting element 201 can be smaller, while the distance between the other parts of the user's finger except the knuckle K and the second light-emitting element 202 can be larger.

[0054] In this way, among the near-infrared light emitted by the first light-emitting element 201 closer to the sensing area 00a, more near-infrared light is emitted to the user's finger joint K, and among the near-infrared light emitted by the second light-emitting element 202 farther from the sensing area 00a, more near-infrared light is emitted to other parts of the user's finger except the finger joint K. Therefore, among the vein distribution images sensed by the finger vein sensor 000 through the infrared detector 300, the vein distribution image at the finger joint K is mainly based on the image obtained by the infrared light provided by the first light-emitting element 201, and the vein distribution images of other parts except the finger joint K are mainly based on the image obtained by the infrared light provided by the second light-emitting element 202. Since the distance between the first light-emitting element 201 and the sensing area 00a is relatively close, the near-infrared light emitted by the first light-emitting element 201 can be emitted to the finger joint K through a relatively short distance, so that the reduced hemoglobin in the finger vein Q at the joint can absorb more near-infrared light, thereby making the effect of the vein distribution image at the user's finger joint K sensed by the finger vein sensor 000 through the infrared light source 200 better. In addition, the distance between the second light emitting element 202 and the sensing area 00a is relatively large, which can ensure that the vein distribution image of the user's middle finger joint K and the vein distribution image other than the finger joint K in the vein distribution image sensed by the finger vein sensor 000 through the infrared light source 200 are relatively small. In this way, the finger vein sensor 000 has a better effect of obtaining the entire vein distribution image inside the user's finger through the infrared light source 200.

[0055] In the present application, compared with the related art that requires a reflector and a macro camera to be set in the finger vein sensor, the finger vein sensor 000 provided in the present application only needs to use an infrared light source 200 and an infrared detector 300 to obtain a vein distribution image inside the user's finger. For example, the thickness of the vein sensor in the related art is 10 mm, and the thickness of the finger vein sensor 000 provided in the present application is only 2 mm. In this way, the finger vein sensor 000 provided in the embodiment of the present application has a smaller thickness, which is conducive to integrating the finger vein sensor 000 with other components in an electronic device, so that the electronic device integrated with the finger vein sensor is smaller in size.

[0056] In summary, the embodiment of the present application provides a finger vein sensor, including: a substrate, an infrared light source and an infrared detector. Since the distance between the first light-emitting element in the infrared light source and the sensing area is smaller than the distance between the second light-emitting element in the infrared light source and the sensing area. Therefore, the near-infrared light emitted by the first light-emitting element will be emitted to the object to be detected in the sensing area through a shorter distance. When the object to be detected is a user's finger, the distance between the finger joints in the user's finger and the first light-emitting element is small, and the near-infrared light emitted by the first light-emitting element can be emitted to the finger joints through a shorter distance, so that the effect of the vein distribution image at the joint is better. And the distance between the other parts of the user's finger except the finger joints and the second light-emitting element is large, which can ensure that the vein distribution image at the middle finger joint of the user's finger and the part except the finger joints in the vein distribution image sensed by the subsequent finger vein sensor through the infrared light source are small. In addition, the finger vein sensor provided in the embodiment of the present application has a small thickness, which is conducive to integrating the finger vein sensor with other components in an electronic device, so that the electronic device integrated with the finger vein sensor is small in size.

[0057] It should be noted that, since the finger vein sensor 000 usually detects the finger vein Q within a certain length range from the fingertip to the palm of the user's finger. Therefore, the length of the infrared detector 300 in the finger vein sensor 000 can be in the range of 25 mm to 50 mm, and the width of the infrared detector 300 in the finger vein sensor 000 can be in the range of 10 mm to 25 mm. In this way, when the user's finger is located in the sensing area 00a of the finger vein sensor 000, the finger vein sensor 000 can sense the finger vein distribution image of the longer part of the user's finger. In this way, when the finger vein sensor 000 is subsequently integrated into an electronic device, the accuracy of the electronic device in detecting the finger vein distribution image can be improved.

[0058] It should also be noted that in order to ensure that the infrared detector 300 in the finger vein sensor 000 can better sense part of the near-infrared light reflected from the user's finger, there needs to be a certain distance between the infrared light source 200 in the finger vein sensor 000 and the sensing area 00a. For example, the distance h1 between the first light-emitting element 201 and the sensing area 00a ranges from 2 mm to 10 mm.

[0059] In the embodiment of the present application, in the same infrared light source 200, the number of the second light emitting elements 202 located on one side of at least one first light emitting element 201 is the same as the number of the second light emitting elements 202 located on the other side of at least one first light emitting element 201. In the same infrared light source 200, when the number of at least one first light emitting element 201 is multiple, the distance between each first light emitting element 201 and the sensing area 00a is equal, and the distance between each second light emitting element 202 and the sensing area is equal 00a. Here, Figure 1 The example shown is a case where there are two first light emitting elements 201 and two second light emitting elements 202. In this way, when the second light emitting elements 202 on both sides of at least one first light emitting element 201 emit near-infrared light, it can be ensured that the near-infrared light directed to the part of the user's finger except the knuckle K has the same light intensity.

[0060] In this application, please refer to Figure 4 , Figure 4 It is a top view of an infrared light source provided in an embodiment of the present application. The infrared light source 200 may also include: a circuit board 203, at least one first light-emitting element 201 and at least two second light-emitting elements 202 are electrically connected to the circuit board 203. Here, the circuit board 203 is used to control multiple first light-emitting elements 201 and multiple second light-emitting elements 202 to emit near-infrared light. The distance h3 between the part of the circuit board 203 used to connect the first light-emitting element 201 and the sensing area 00a is smaller than the distance h4 between the part of the circuit board 203 used to connect the second light-emitting element 202 and the sensing area 00a. In this way, it can be ensured that the distance h1 between the first light-emitting element 201 and the sensing area 00a is smaller than the distance h2 between the second light-emitting element 202 and the sensing area 00a, thereby making the effect of the entire vein distribution image inside the user's finger better.

[0061] In the examples of this application, please refer to Figure 5 , Figure 5 It is a top view of another infrared light source provided in an embodiment of the present application. The circuit board 203 in the infrared light source 200 is in a strip shape, and the circuit board 203 has a first strip portion 2031 connected to the first light-emitting element 201, and a second strip portion 2032 connected to the second light-emitting element 2022. The minimum distance h5 between the first strip portion 2031 and the sensing area 00a is smaller than the minimum distance h6 between the second strip portion 2032 and the sensing area 00a. In this way, it can also ensure that the finger vein sensor 000 can sense the entire vein distribution image inside the user's finger better.

[0062] It should be noted that, within the peripheral area 00b of the finger vein sensor 000, the area between the portion of the circuit board 203 used to connect the first light-emitting element 201 and the sensing area 00a can also be used to arrange other data signal lines, and the area between the portion of the circuit board 203 used to connect the second light-emitting element 202 and the sensing area 00a can also be used to arrange other data signal lines, which is conducive to the finger vein sensor 000 to achieve a narrow frame effect, so that the sensing area 00a of the finger vein sensor 000 is larger.

[0063] In this application, if Figure 5 As shown, the circuit board 203 in the infrared light source 200 is an arc-shaped strip circuit board. In other possible implementations, the circuit board 203 in the infrared light source 200 can also be other irregular shapes, which is not limited in the embodiment of the present application.

[0064] In the examples of this application, please refer to Figure 6 , Figure 6 : is a schematic diagram of the structure of a finger vein sensor provided in an embodiment of the present application. In the direction perpendicular to the substrate 100, the height H1 of the first light-emitting element 201 is less than the height H2 of the second light-emitting element 202. In this way, in the direction perpendicular to the substrate 100, the light-emitting surface of the first light-emitting element 201 is closer to the substrate 100 than the light-emitting surface of the second light-emitting element 202. For example, the light-emitting surface of the first light-emitting element 201 differs from the light-emitting surface of the second light-emitting element 202 by 0.01 mm to 1 mm. Here, since the finger veins at the knuckles of the user's fingers are closer to the skin surface, the near-infrared light directed to the knuckles needs to be as perpendicular as possible to the skin surface at the knuckles, so that the finger veins at the knuckles close to the skin surface can absorb the near-infrared light directed to the knuckles.

[0065] In this case, when the knuckles of the user's fingers are located in the sensing area 00a, and the distance between the knuckles of the user's fingers and the light-emitting surface of the first light-emitting element 201 is large, the first light-emitting element 201 emits near-infrared light, which can be vertically directed to the knuckles of the user's fingers, so that most of the near-infrared light directed to the knuckles can be absorbed by the finger veins close to the skin surface at the knuckles, thereby making the effect of the vein distribution image of the user's finger joints sensed by the finger vein sensor 000 through the infrared light source 200 better. In addition, when the distance between the knuckles of the user's fingers and the light-emitting surface of the first light-emitting element 201 is large, the distance between the part of the user's fingers other than the knuckles and the light-emitting surface of the second light-emitting element 202 is small, so that the difference between the vein distribution images of the middle finger joints of the user's fingers and the part other than the knuckles in the vein distribution image sensed by the finger vein sensor is small. In this way, the effect of the vein distribution image of the entire inside of the user's finger sensed by the finger vein sensor 000 through the infrared light source 200 is better.

[0066] In the examples of this application, please refer to Figure 7 and Figure 8 , Figure 7 is a top view of another finger vein sensor provided in an embodiment of the present application, Figure 8 yes Figure 7 The structural diagram at A-A' is shown. One side of the substrate 100 in the finger vein sensor 000 for carrying at least one infrared light source 200 and an infrared detector 300 is an arc-shaped concave surface, and the arc extension direction of the arc-shaped concave surface intersects with the overall extension direction of the infrared light source 200. Here, the concave surface formed by the arc-shaped substrate can facilitate the user to place the finger in the arc-shaped concave surface, so as to bring a better experience to the user.

[0067] In this case, since the substrate 100 is an arc-shaped concave surface, in the vertical direction, the position of the infrared light source 200 on the arc-shaped substrate 100 is higher than the lowest position of the infrared detector 300 on the arc-shaped substrate 100, that is, there is a height difference H3 between the lowest points of the infrared light source 200 and the infrared detector 300. For example, in the vertical direction, the height difference H3 between the lowest points of the infrared light source 200 and the infrared detector 300 ranges from 2 mm to 10 mm. In this way, when the user's finger is located in the sensing area 00a, the near-infrared light emitted by the infrared light source 200 is at a shorter distance from the user's finger, so that the near-infrared light emitted by the infrared light source 200 can be fully absorbed by the finger veins in the user's finger, thereby making the effect of the vein distribution image sensed by the finger vein sensor 000 better.

[0068] Furthermore, since the substrate 100 is an arc-shaped concave surface, the finger vein distribution image sensed by the finger vein sensor 000 includes not only the position information of the finger vein distribution in the user's finger, but also the depth information of the finger vein in the user's finger. In this way, the security and accuracy of the finger vein distribution image sensed by the finger vein sensor 000 provided in the present application are greatly improved accordingly.

[0069] In the embodiment of the present application, one side of the substrate 100 in the finger vein sensor 000 for carrying at least one infrared light source 200 and an infrared detector 300 is a circular arc concave surface, and the arc angle α of the circular arc concave surface ranges from 10° to 60°. Here, the radius R corresponding to the circular arc concave surface can range from 5 cm to 20 cm.

[0070] In this application, please refer to Fig. 9 , Fig. 9: is a working schematic diagram of another finger vein sensor provided in an embodiment of the present application. The angle between the optical axis of the first light-emitting element 201 and the substrate 100, and the angle C1 between the optical axis of the second light-emitting element 202 and the substrate 100 are both in the range of 30° to 90°. Here, the optical axis of the infrared light source 200 refers to the optical path of the near-infrared light emitted by the infrared light source 200 that is directed toward the finger vein Q in the user's finger. In this way, it can be ensured that the near-infrared light emitted by the infrared light source 200 can be directed toward the user's finger.

[0071] In the embodiment of the present application, since the near-infrared light emitted by the infrared light source 200 is divergent, the near-infrared light emitted by the infrared light source 200 has a divergence angle C2. The divergence angle C2 refers to: the angle between the near-infrared light at the outermost boundary of the near-infrared light emitted by the infrared light source 200. Here, the larger the divergence angle C2 of the near-infrared light, the more angles that can be selected for the angle C1 between the optical axis of the infrared light source 200 and the substrate 100. In this way, no matter whether the user's finger is thicker or thinner, after the user places the finger in the sensing area 00a, the near-infrared light emitted by the infrared light source 200 in the finger vein sensor 000 can be directed to the user's finger, ensuring that the finger vein sensor 000 can generate a finger vein image based on part of the near-infrared light reflected back from the user's finger.

[0072] It should be noted that in other possible implementations, the divergence angle C2 of the infrared light source 200 and the angle C1 between the optical axis of the infrared light source 200 and the substrate 100 can be adjusted according to the shape of the substrate 100 in the finger vein sensor 000, so that the light emitted by the infrared light source 200 can be directed to the user's finger. This embodiment of the application is not limited to this.

[0073] It should also be noted that if Figure 1 , Figure 8 and Fig. 9As shown, there can be multiple combinations of the distance (h1, h2) between the infrared light source 200 and the sensing area 00a, the height difference H3 between the infrared light source 200 and the lowest point of the infrared detector 300, the divergence angle C2 of the infrared light source 200, and the angle C1 between the optical axis of the infrared light source 200 and the substrate 100 to ensure that the finger vein image generated by the finger vein sensor 000 is better. Here, the infrared light source 200 in the finger vein sensor 000 can be adjusted according to the following relationship: the smaller the distance (h1, h2) between the infrared light source 200 and the sensing area 00a, the larger the angle C1 between the optical axis of the infrared light source 200 and the substrate 100; the smaller the height difference H3 between the lowest point of the infrared light source 200 and the infrared detector 300, the larger the angle C1 between the optical axis of the infrared light source 200 and the substrate 100; the larger the divergence angle C2 of the near-infrared light, the more angles can be selected for the angle C1 between the optical axis of the infrared light source 200 and the substrate 100. For example, if the divergence angle C2 of the near-infrared light is larger, the angle C1 between the optical axis of the infrared light source 200 and the substrate 100 can be selected more, and the infrared light source 200 in the finger vein sensor 000 is adjusted. The corresponding beneficial effects can refer to the corresponding contents in the above embodiments, and this application will not elaborate on this.

[0074] In the embodiment of the present application, in order to more clearly see the structure of the infrared detector 300, please refer to Fig.10 , Fig.10 Schematic diagram of a film layer of an infrared detector provided in an embodiment of the present application. The infrared detector 300 may include: a plurality of driving circuits 301 located on a substrate 100, a semiconductor layer 302 located on a side of the plurality of driving circuits 301 facing away from the substrate 100, and a transparent electrode layer 303 located on a side of the semiconductor layer 302 facing away from the substrate 100.

[0075] The semiconductor layer 302 is electrically connected to a plurality of driving circuits 301 and a transparent electrode layer 303, respectively. In this way, after a bias voltage is applied to the transparent electrode layer 303, the semiconductor layer 302 in the finger vein sensor 000 is in a working state. In this way, when the user's finger is placed in the sensing area 00a of the finger vein sensor 000 and the infrared light source 200 emits near-infrared light, the semiconductor layer 302 senses part of the near-infrared light reflected from the user's finger, and the semiconductor layer 302 can respond to the received near-infrared light, thereby generating and storing a photocurrent signal. Afterwards, the finger vein sensor 000 can apply a voltage to the gate 3022 in the driving circuit 301, and the photocurrent signal can be derived from the driving circuit 301 in the form of an electrical signal.

[0076] In the embodiment of the present application, each driving circuit 301 may include: a gate electrode 3011, a first electrode 3012, a second electrode 3013, an active layer 3014 and a switching electrode 3015. Among them, the electrode 3011, the first electrode 3012, the second electrode 3013 and the active layer 3014 can form a thin film transistor, in which the first electrode 3012 and the second electrode 3013 are both overlapped with the active layer 3014, and the active layer 3014 is insulated from the gate electrode 3011. For example, the active layer 3014 and the gate electrode 3011 can be insulated by a gate insulating layer 3016. It should be noted that the first electrode 3012 in the thin film transistor can be one of the source electrode and the drain electrode, and the second electrode 3013 can be the other of the source electrode and the drain electrode. Here, the switching electrode 3015 in the driving circuit 301 is electrically connected to the second electrode 3013 in the thin film transistor.

[0077] The finger vein sensor 000 may also include: a flat layer 400 stacked vertically and away from the side of the substrate 100, and the flat layer 400 has a plurality of openings V. In this way, a portion of the switching electrode 3015 is located in the opening V, and another portion of the switching electrode 3015 is located on the side of the flat layer 400 away from the substrate 100. In this way, the semiconductor layer 302 is electrically connected to the thin film transistor in the driving circuit 301 through the switching electrode 3015. Here, the orthographic projection of the thin film transistor on the substrate 100 is located within the orthographic projection of the switching electrode 3015 on the substrate 100, and the switching electrode 3015 is usually made of an opaque metal material. In this way, the switching electrode 3015 can shield the active layer 3014 in the thin film transistor to avoid the phenomenon of voltage threshold shift of the active layer 3014 under the irradiation of interfering light.

[0078] It should be noted that, since the transfer electrode 3015 is made of metal material, in order to prevent the transfer electrode 3015 made of metal material from being oxidized and affecting the electrical connection effect between the transfer electrode 3015 and the semiconductor layer 302 during the manufacturing process of the infrared detector 300, the present application provides a protective electrode 3015a that is conductive and will not be oxidized on the side of the transfer electrode 3015 away from the substrate 100, so that the transfer electrode 3015 is not easily oxidized. It should also be noted that, in order to prevent interference between the transfer electrode 3015 and the thin film transistor, it is necessary to ensure that the thickness of the flat layer 400 is large.

[0079] In the present application, the semiconductor layer 302 is a planar structure provided in an entire layer, or the semiconductor layer 303 has a plurality of semiconductor blocks corresponding one-to-one to the driving circuits 301 , and the plurality of semiconductor blocks are electrically connected one-to-one to the plurality of driving circuits 301 .

[0080] When the semiconductor layer 302 is a planar structure provided as a whole layer, such as Fig.10As shown, the transparent electrode layer 303 is provided as a whole layer. Thus, the portion of the semiconductor layer 302 electrically connected to each switching electrode 3015 is a sensing unit of the semiconductor layer 302, that is, a minimum unit in the semiconductor layer 302 for sensing a portion of the near-infrared light reflected from the user's finger.

[0081] When the semiconductor layer 302 has a plurality of semiconductor blocks 302a corresponding to the driving circuits 301 one by one, and the plurality of semiconductor blocks 302a are electrically connected to the plurality of driving circuits 301 one by one, please refer to Fig.11 , Fig.11 301 is a schematic diagram of a film layer of another infrared detector provided in an embodiment of the present application. The infrared detector 300 may also include: a plurality of raised structures 304 located on the side of the flat layer 400 away from the substrate. The raised structure 304 is located between any two switching electrodes 3015. In this way, a semiconductor block 302a electrically connected to the switching electrode 3015 is a sensing unit of the semiconductor layer 302. In this case, when the user's finger is placed in the sensing area 00a of the finger vein sensor 000 and the infrared light source 200 emits near-infrared light, each semiconductor block 302a can respond to part of the near-infrared light reflected from the user's finger, and each semiconductor block 302a will generate photogenerated carriers. The raised structure 304 can prevent the photogenerated carriers generated between two adjacent semiconductor blocks 302a from crosstalking, thereby preventing the photocurrent signals sensed by each sensing unit in the infrared detector 300 from being inaccurate.

[0082] In the examples of this application, please refer to Fig.12 , Fig.12 It is a schematic diagram of a film layer of a semiconductor layer provided in an embodiment of the present application. The semiconductor layer 302 is a PIN structure composed of an electron transport layer 3021, a photoelectric conversion layer 3022 and a hole transport layer 3023. Among them, the electron transport layer 3021 can be prepared from electron-rich materials such as zinc oxide and tin oxide, the hole transport layer 3023 can be prepared from hole-rich materials such as poly 3,4-ethylenedioxythiophene / polystyrene sulfonate, and the photoelectric conversion layer 3022 can be a heterojunction structure obtained by mixing an acceptor semiconductor material and a donor semiconductor material. Here, the acceptor semiconductor material can be composed of a fullerene derivative, and the donor semiconductor material can be composed of one of polythiophene-pyrrolopyrrole diketone, poly 3-ethylthiophene and oligothiophene and benzo[1,2-b:4,5-b']dithiophene.

[0083] In the present application, the transparent electrode layer 303 in the infrared detector 300 can be a layered structure made of transparent conductive materials such as indium tin oxide (ITO), indium-doped zinc oxide (IZO), a derivative of polythiophene, polyethylene dioxythiophene (PEDOT), or silver nanowires.

[0084] In the examples of this application, please refer to Fig.13 , Fig.13 It is a schematic diagram of the film layer of another infrared detector provided in an embodiment of the present application. The infrared detector 300 may also include: an encapsulation layer 305 located on the side of the semiconductor layer 302 facing away from the substrate 100, and an optical collimation layer 306 located on the side of the encapsulation layer 305 facing away from the substrate 100. Here, the encapsulation layer 305 is used to provide protection for the semiconductor layer 302 to prevent water and oxygen from corroding the semiconductor layer 302. The optical collimation layer 306 allows the near-infrared light within a preset angle range of part of the near-infrared light reflected from the user's finger to pass through. Here, the preset angle range is: the angle between the normal line of the optical collimation layer 306 is in the range of 5° to 10°. In this way, the finger vein sensor 000 can avoid the situation where near-infrared light at a large angle is directed to the semiconductor layer 302, thereby interfering with the semiconductor layer 302.

[0085] It should be noted that the normal line of the optical collimation layer 306 is a reference line perpendicular to the surface of the optical collimation layer 306. The encapsulation layer 305 can be an encapsulation film composed of polyethylene terephthalate, or the encapsulation layer 305 can be an encapsulation film composed of silicon oxide, resin material, and silicon oxide stacked. This embodiment of the application is not limited to this.

[0086] In the embodiment of the present application, there are many structures of the optical alignment layer 306, and the embodiment of the present application only takes the following two structures as examples for schematic description:

[0087] For the first structure, please refer to Fig.14 and Fig.15 , Fig.14 is a schematic diagram of the structure of an optical collimation layer provided in an embodiment of the present application, Fig.15306a is a top view of an optical collimation layer provided in an embodiment of the present application. The optical collimation layer 306 is composed of a plurality of collimation units 306a arranged in a honeycomb shape, the heights of the plurality of collimation units 306a are the same, and the plurality of collimation units 306a are coplanar on the side facing away from the substrate 100. Here, the collimation unit 306a may be a plurality of cylinders, the sidewalls of the cylinders are made of a light-absorbing material, and the cylinder bodies of the cylinders are made of a transparent material. For example, the collimation unit 306a may be an optical fiber wrapped with a light-absorbing material. In this way, the near-infrared light with a large angle in part of the near-infrared light reflected from the user's finger can be absorbed by the light-absorbing material on the sidewalls in the collimation unit 306a, and the near-infrared light within a preset range in part of the near-infrared light reflected from the user's finger can pass through the transparent material in the collimation unit 306a and be emitted to the semiconductor layer 302. For example, the thickness H4 of the optical collimating layer 306 ranges from 0.1 mm to 0.4 mm, and the diameter r of each collimating unit 306 a ranges from 4 μm to 80 μm.

[0088] For the second structure, please refer to Fig.16 , Fig.16 306a. The optical collimation layer 306 is composed of a plurality of collimation units 306a arranged in a honeycomb shape. Each collimation unit 306a may include: a convex lens 3061, a first light absorption structure 3062, and a second light absorption structure 3063. The convex lens 3061 can gather part of the near-infrared light reflected from the user's finger in a collimation unit 306a. The first light absorption structure 3062 can absorb the near-infrared light of a large angle in a collimation unit 306a, and prevent the near-infrared light in two adjacent collimation units 306a from crosstalk. The second light absorption structure 3063 can absorb the light that does not meet the preset range in the near-infrared light of a small angle. In this way, after part of the near-infrared light reflected from the user's finger passes through the collimation unit 306a, only the near-infrared light of a small angle that meets the preset range is emitted from the opening t and directed toward the semiconductor layer 302.

[0089] It should be noted that in the above two structures, the orthographic projection of at least one collimating unit 306a on the substrate 100 is located within the orthographic projection of the switching electrode 3015 on the substrate 100. In this way, it can be ensured that each sensing unit in the semiconductor layer 302 can sense part of the near-infrared light reflected from the user's finger.

[0090] In the embodiment of the present application, the infrared detector 300 may further include: a filter film 307. Fig.13 As shown, the filter film 307 is located between the packaging layer 305 and the optical alignment layer 306. Alternatively, please refer to Fig.17 , Fig.173 is a schematic diagram of the film layer of another infrared detector provided in an embodiment of the present application. The filter film 307 is located on the side of the optical collimation layer 306 away from the substrate 100, and the filter film 305 is used to filter light except infrared light. In this way, it can be ensured that the semiconductor layer 302 will not be disturbed by ambient light, which is beneficial to improving the sensing effect of the finger vein sensor 000. It should be noted that the filter film 307 can be any one of a black ink material, a reflective film, and a filter that only allows infrared light to pass through.

[0091] In this application, please refer to Fig.18 , Fig.18 It is a schematic diagram of the structure of another finger vein sensor provided in an embodiment of the present application. The finger vein sensor 000 may also include: a sensing electrode 500 located on the side of the infrared detector 300 facing away from the substrate 100, and a controller 600 electrically connected to the sensing electrode 500, at least one infrared light source 200 and the infrared detector 300, respectively. Here, there are two sensing electrodes 500. After the user places the finger in the sensing area 00a of the finger vein sensor 000, both sensing electrodes 500 are in contact with the user's finger, so that a loop is formed between the two sensing electrodes 500 of the user and the controller 600. In this way, after sensing the current in the loop, the controller 600 can apply an electrical signal to the infrared light source 200 and the infrared detector 300 so that the infrared light source 200 and the infrared detector 300 can work.

[0092] Furthermore, the sensing electrode 500 can also prevent static electricity from being generated in the finger vein sensor 000 and affecting the infrared light source 200 and the infrared detector 300. It should be noted that the driving circuit 301 and the transparent electrode 303 in the above embodiment are both electrically connected to the controller 600. The controller 600 can apply a bias voltage to the transparent electrode 303 and a voltage to the gate 3011 in the driving circuit 301.

[0093] In the embodiment of the present application, the finger vein sensor 000 may also include: a virtual electrode 700 located around the infrared detector 300, the virtual electrode 700 is also electrically connected to the controller 600, and the structure of the virtual electrode 700 is the same as that in the infrared detector 300. Here, after the finger vein sensor 000 is working, the virtual electrode 700 is turned on but cannot receive near-infrared light. In this way, the controller 600 can process the finger vein information sensed by the infrared detector 300 according to the electrical signal generated on the virtual electrode 700, remove the interference caused by the circuit itself, so that the effect of the finger vein image information sensed by the finger vein sensor 000 is better.

[0094] In summary, the embodiment of the present application provides a finger vein sensor, including: a substrate, an infrared light source and an infrared detector. Since the distance between the first light-emitting element in the infrared light source and the sensing area is smaller than the distance between the second light-emitting element in the infrared light source and the sensing area. Therefore, the near-infrared light emitted by the first light-emitting element will be emitted to the object to be detected in the sensing area through a shorter distance. When the object to be detected is a user's finger, the distance between the finger joints in the user's finger and the first light-emitting element is small, and the near-infrared light emitted by the first light-emitting element can be emitted to the finger joints through a shorter distance, so that the effect of the vein distribution image at the joint is better. And the distance between the other parts of the user's finger except the finger joints and the second light-emitting element is large, which can ensure that the vein distribution image at the middle finger joint of the user's finger and the part except the finger joints in the vein distribution image sensed by the subsequent finger vein sensor through the infrared light source are small. In addition, the finger vein sensor provided in the embodiment of the present application has a small thickness, which is conducive to integrating the finger vein sensor with other components in an electronic device, so that the electronic device integrated with the finger vein sensor is small in size.

[0095] The present application also provides an electronic device, which may include: a housing, and a finger vein sensor 000 connected to the housing, wherein the finger vein sensor 000 is any of the above-mentioned finger vein sensors 000. Here, the electronic device may be a medical device, a wearable device, and a device for identification and authentication. When the electronic device is a wearable device, the wearable device may be a smart watch, a smart bracelet, or a smart ring. Please refer to Fig.19 , Fig.19 This is a rendering of a user wearing a wearable device provided by an embodiment of the present application. If the finger vein sensor is integrated into the wearable device, the wearable device has the function of identifying whether the user is an authorized user. For example, the wearable device can detect the finger vein image of the user through the finger vein sensor 000, and determine whether the user is an authorized user based on the detected finger vein image. When the wearable device determines that the user is an authorized user, the wearable device can turn on the service function for the user to use; when the wearable device determines that the user is an unauthorized user, the wearable device can turn off the service function, and the user cannot use the wearable device normally.

[0096] It should be noted that in the accompanying drawings, the sizes of layers and regions may be exaggerated for clarity of illustration. It is also understood that when an element or layer is referred to as being "on" another element or layer, it may be directly on the other element, or there may be an intermediate layer. In addition, it is understood that when an element or layer is referred to as being "under" another element or layer, it may be directly under the other element, or there may be more than one intermediate layer or element. In addition, it is also understood that when a layer or element is referred to as being "between" two layers or two elements, it may be the only layer between the two layers or two elements, or there may also be more than one intermediate layer or element. Similar reference numerals throughout the text indicate similar elements.

[0097] In the present application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "plurality" refers to two or more than two, unless otherwise clearly defined.

[0098] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A finger vein sensor, It is characterized in that The finger vein sensor has a sensing area and a peripheral area around the sensing area, and the finger vein sensor includes: substrate; at least one infrared light source located on the substrate and distributed in the peripheral area, the infrared light source comprising: at least one first light-emitting element and at least two second light-emitting elements located on both sides of the at least one first light-emitting element, the distance between the first light-emitting element and the sensing area is smaller than the distance between the second light-emitting element and the sensing area, so that the near-infrared light emitted to the finger joints adjacent to the first light-emitting element is greater than the near-infrared light emitted to other parts of the finger adjacent to the second light-emitting element except the finger joints; and in the direction perpendicular to the substrate, the height of the first light-emitting element is smaller than the height of the second light-emitting element; And, infrared detectors located on the substrate and distributed in the sensing area, the infrared detectors are configured to: after the object to be detected is located in the sensing area and the at least one infrared light source emits infrared light to the object to be detected, detect the infrared light reflected by the object to be detected.

2. The finger vein sensor according to claim 1, It is characterized in that The infrared light source also includes: a circuit board, the at least one first light-emitting element and the at least two second light-emitting elements are electrically connected to the circuit board, and the distance between a portion of the circuit board used to connect the first light-emitting element and the sensing area is smaller than the distance between a portion of the circuit board used to connect the second light-emitting element and the sensing area.

3. The finger vein sensor according to claim 2, It is characterized in that The circuit board is in a strip shape, and has a first strip portion connected to the first light-emitting element, and a second strip portion connected to the second light-emitting element, and a minimum distance between the first strip portion and the sensing area is smaller than a minimum distance between the second strip portion and the sensing area.

4. The finger vein sensor according to claim 3, It is characterized in that The circuit board is an arc-shaped strip circuit board.

5. The finger vein sensor according to any one of claims 1 to 4, It is characterized in that In the same infrared light source, the number of the second light-emitting elements located on one side of the at least one first light-emitting element is the same as the number of the second light-emitting elements located on the other side of the at least one first light-emitting element.

6. The finger vein sensor according to any one of claims 1 to 4, It is characterized in that A surface of the substrate used for carrying the at least one infrared light source and the infrared detector is an arc-shaped concave surface, and an arc-shaped extension direction of the arc-shaped concave surface intersects with an overall extension direction of the infrared light source.

7. The finger vein sensor according to claim 6, It is characterized in that A surface of the substrate used for carrying the at least one infrared light source and the infrared detector is an arc concave surface, and the curvature of the arc concave surface ranges from 10° to 60°.

8. The finger vein sensor according to any one of claims 1 to 4, It is characterized in that The angle between the optical axis of the first light-emitting element and the substrate, and the angle between the optical axis of the second light-emitting element and the substrate are both in the range of 30° to 90°.

9. The finger vein sensor according to any one of claims 1 to 4, It is characterized in that The infrared detector comprises: a plurality of driving circuits located on the substrate, a semiconductor layer located on a side of the plurality of driving circuits away from the substrate, and a transparent electrode layer located on a side of the semiconductor layer away from the substrate; Wherein, the semiconductor layer is electrically connected to the plurality of driving circuits and the transparent electrode layer respectively.

10. The finger vein sensor according to claim 9, It is characterized in that The semiconductor layer is a planar structure provided in an entire layer, or the semiconductor layer has a plurality of semiconductor blocks corresponding one to one with the driving circuits, and the plurality of semiconductor blocks are electrically connected one to one with the plurality of driving circuits.

11. The finger vein sensor according to claim 9, It is characterized in that The infrared detector further includes: a packaging layer located on a side of the semiconductor layer away from the substrate, and an optical alignment layer located on a side of the packaging layer away from the substrate.

12. The finger vein sensor according to claim 11, It is characterized in that The infrared detector further includes: a filter film, which is located between the packaging layer and the optical collimation layer, or the filter film is located on a side of the optical collimation layer away from the substrate, and is used to filter light except the infrared light.

13. The finger vein sensor according to any one of claims 1 to 4, It is characterized in that The finger vein sensor further includes: a sensing electrode located on a side of the infrared detector facing away from the substrate, and a controller electrically connected to the sensing electrode, the at least one infrared light source and the infrared detector respectively.

14. An electronic device, It is characterized in that The invention comprises: a shell, and a finger vein sensor connected to the shell, wherein the finger vein sensor is the finger vein sensor according to any one of claims 1 to 13.

Images