CN112580388A

CN112580388A - Fingerprint identification module, scanning method thereof, storage medium and electronic equipment

Info

Publication number: CN112580388A
Application number: CN201910924125.6A
Authority: CN
Inventors: 黄建东
Original assignee: Shanghai Harvest Intelligence Tech Co Ltd
Current assignee: Shanghai Harvest Intelligence Tech Co Ltd
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2021-03-30

Abstract

The utility model provides a fingerprint identification module and scanning method, storage medium, electronic equipment thereof, the fingerprint identification module includes: a light transmissive cover plate having opposing first and second faces; a light source component located below the second face of the light transmissive cover sheet, the light source component including a plurality of light source points; a sensor part located under the light source part, the sensor part including a plurality of light sensing units, each light sensing unit including a red identification area, a green identification area, and a blue identification area. The technical scheme of the invention can improve the fingerprint acquisition efficiency.

Description

Fingerprint identification module, scanning method thereof, storage medium and electronic equipment

Technical Field

The invention relates to the technical field of image imaging, in particular to a fingerprint identification module, a scanning method of the fingerprint identification module, a storage medium and electronic equipment.

Background

With the development of information technology, biometric identification technology plays an increasingly important role in ensuring information security, and fingerprint identification has become one of the key technical means for identity identification and equipment unlocking widely applied in the field of mobile internet. Under the trend that the screen of equipment accounts for more and more, traditional capacitive fingerprint identification can not meet the requirements, and ultrasonic fingerprint identification has the problems in the aspects of technical maturity, cost and the like, and optical fingerprint identification is a mainstream technical scheme expected to become the screen fingerprint identification.

The existing optical fingerprint identification scheme is based on the imaging principle of a geometric optical lens, and the used fingerprint module comprises a micro-lens array, an optical spatial filter and other elements. The optical fingerprint identification under the lens-free screen is realized by the total reflection imaging principle of physical optics. At present, a common uniform illumination light source cannot meet the requirement of a total reflection imaging principle, and a point light source array is a necessary light source for an optical fingerprint imaging scheme under a lens-free screen.

However, the single imaging of the existing fingerprint imaging module can only acquire a single screen image, and in order to acquire a complete fingerprint image, the image of more times needs to be acquired, so that the fingerprint acquisition efficiency is low.

Disclosure of Invention

The technical problem solved by the invention is how to improve the fingerprint acquisition efficiency.

In order to solve the above technical problem, an embodiment of the present invention provides a fingerprint identification module, where the fingerprint identification module includes: a light transmissive cover plate having opposing first and second faces; a light source component located below the second face of the light transmissive cover sheet, the light source component including a plurality of light source points; a sensor part located under the light source part, the sensor part including a plurality of light sensing units, each light sensing unit including a red identification area, a green identification area, and a blue identification area.

Optionally, the plurality of light source points are arranged in an array.

Optionally, the plurality of light source points are arranged in an array selected from a transverse arrangement, a longitudinal arrangement and a ring arrangement.

Optionally, each photosensitive unit includes a red filter, a green filter and a blue filter, the red filter is located in the red identification area, the green filter is located in the green identification area, and the blue filter is located in the blue identification area.

Optionally, when the sensor component is a thin film transistor sensor, the area of the blue identification region is larger than the area of any one of the red identification region and the green identification region.

Optionally, the light source colors of the plurality of light source points are colors.

Optionally, the light source component is a liquid crystal display, an active array organic light emitting diode display or a micro light emitting diode display.

In order to solve the technical problem, the embodiment of the invention also discloses an image scanning method based on the fingerprint identification module, and the image scanning method comprises the following steps: illuminating light source points in a plurality of discrete point light source regions of the light source part, wherein non-illuminating light source points are arranged among the point light source regions in an array mode and are spaced; the light of the luminous light source points totally reflected by the light-transmitting cover plate is obtained through the sensor part, and each photosensitive unit in the sensor part can identify red, green and blue in the light; after the preset time interval, after the same position deviation is carried out on all the point light source areas, the luminous light source points in a plurality of separated point light source areas of the light source part are lightened iteratively, and the light rays of the luminous light source points totally reflected by the light-transmitting cover plate are obtained through the sensor part until the number of the position deviation reaches the preset number.

Optionally, the image scanning method further includes: and splicing according to the light ray data acquired by the optical sensor component to acquire image data.

Optionally, the direction of the position deviation is from the light source point area to the adjacent point light source area; the distance of the position deviation is an integral fraction of the distance between the adjacent point light source regions.

Optionally, the positional offset includes a lateral offset, a longitudinal offset, and a ± 45 ° directional offset

Optionally, the spot light source region is quasi-circular.

Optionally, the distance between two adjacent point light sources satisfies the condition that the point light source total reflection images collected by the sensor component are not in contact with and are not repeated.

The embodiment of the invention also discloses a storage medium, wherein computer instructions are stored on the storage medium, and the steps of the image scanning method are executed when the computer instructions are executed.

The embodiment of the invention also discloses electronic equipment which comprises a memory and a processor, wherein the memory is stored with computer instructions capable of running on the processor, and the processor executes the steps of the image scanning method when running the computer instructions.

Compared with the prior art, the technical scheme of the embodiment of the invention has the following beneficial effects:

according to the technical scheme, the sensor component of the fingerprint identification module comprises a plurality of photosensitive units, each photosensitive unit comprises a red identification area, a green identification area and a blue identification area, the identification areas with different colors are arranged in each photosensitive unit, so that the fingerprint identification module can simultaneously collect 3 images in the single imaging process, and compared with the prior art in which only a single image can be collected in the single imaging process, the collection times can be reduced when a complete fingerprint image is collected, the complete fingerprint image can be more quickly obtained, and the fingerprint collection efficiency is improved.

Further, when the sensor component is a thin film transistor sensor, the area of the blue identification region is larger than the area of either one of the red identification region and the green identification region. In the technical scheme of the invention, because the thin film transistor sensor has weaker sensitivity to blue light, the area of the blue identification area can be set to be larger so as to obtain more blue light and ensure the quality of image acquisition.

Drawings

Fig. 1 is a schematic structural diagram of a fingerprint identification module according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a specific structure of a photosensitive unit according to an embodiment of the present invention;

FIG. 3 is a flow chart of an image scanning method according to an embodiment of the invention;

fig. 4 is a schematic structural diagram of an image scanning apparatus according to an embodiment of the present invention.

Detailed Description

Like in the background art, the image under single screen can only be acquireed in current fingerprint formation of image module single formation of image, in order to obtain complete fingerprint image, need gather the image of more number of times, fingerprint collection inefficiency.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

Fig. 1 is a schematic structural diagram of a fingerprint identification module according to an embodiment of the present invention.

As shown in fig. 1, the fingerprint recognition module may include a light-transmissive cover 101, a light source part 102, and a sensor part 103.

Wherein, the light-transmitting cover plate 101 has a first face 101a and a second face 101b which are opposite. The light source part 102 is located under the second face 101b of the light-transmissive cover plate 102, and the light source part 102 includes a plurality of light source points, as indicated by reference numerals P1 and P2 in fig. 1.

Specifically, the transparent cover 101 may be a single-layer structure or a multi-layer structure, the single-layer structure may be a glass cover or an organic transparent cover, and the single-layer cover may also be a cover with other functions, such as a touch screen. The multilayer structure can be a multilayer glass cover plate or a multilayer organic light-transmitting material cover plate or a combination of a glass cover plate and an organic light-transmitting material cover plate.

Specifically, the light source section 102 may be a display panel which can emit light not only as a light source but also for displaying an image. The display panel may include a Liquid Crystal Display (LCD), an active array organic light emitting diode (AMOLED) display, or a micro-light emitting diode (micro-LED) display, which scans and drives a single pixel in a Thin Film Transistor (TFT) structure, so that a single driving of a pixel point may be realized, that is, a driving and an array display of a point light source may be realized, and light may enter the sensor part 103 through a gap between pixel points.

Further, the color of the light source emitted from the light source point may be white, and the white light may be decomposed into a plurality of colors, so that the sensor part 103 may recognize the light as different colors through the different color recognition regions after acquiring the light.

Specifically, the light-transmissive cover 101 and the display panel may be filled with an optical adhesive for connection and to prevent air from affecting the reflection of light, and the refractive index of the optical adhesive should be as equal as possible to the refractive index of the light-transmissive cover 101 to prevent the light from being totally reflected between the light source component 102 (e.g., the display panel) and the light-transmissive cover 101.

A sensor member 103 may be used to acquire light, the sensor member 103 being located below the light source member 102. The sensor part 103 may include a plurality of light sensing units (not shown), and may be separately disposed under the display panel.

Referring to fig. 1 and 2 together, the light sensing unit may include a red identification zone 1031, a green identification zone 1032, and a blue identification zone 1033. The red identification zone 1031 may be used to obtain red light, the green identification zone 1032 may be used to obtain green light, and the blue identification zone 1033 may be used to obtain blue light.

In a specific application scenario of the present invention, the principle of total reflection imaging is that when imaging is performed, a finger 100 is in contact with a transparent cover plate 101, due to air in a fingerprint depression, light rays with an incident angle exceeding a critical angle of total reflection will form total reflection, a sensor component 103 will collect bright light rays, while a fingerprint protrusion is in contact with the upper surface of the transparent cover plate 101, light rays will not generate total reflection, and the sensor component 103 will collect dark light rays, so that a fingerprint image can be distinguished.

In the embodiment of the invention, the sensor component of the fingerprint identification module comprises a plurality of photosensitive units, each photosensitive unit comprises a red identification area, a green identification area and a blue identification area, and the identification areas with different colors are arranged in each photosensitive unit, so that the fingerprint identification module can simultaneously collect 3 images in the single imaging process, and only a single image can be collected in comparison with the single imaging in the prior art, the collection times can be reduced when a complete fingerprint image is collected, the complete fingerprint image can be more quickly obtained, and the fingerprint collection efficiency is improved.

In one non-limiting embodiment of the present invention, the plurality of light source points are arranged in an array.

In this embodiment, the array arrangement of the point light sources may have a plurality of arrangement modes, for example, the point light sources may be arranged uniformly, that is, the distances between every two point light sources are equal, so that the light emitted by each point light source is reflected to form the same image, which is convenient for subsequent image processing.

Further, the plurality of light source points are arranged in an array selected from a transverse arrangement, a longitudinal arrangement and a circular arrangement.

Specifically, the plurality of point light sources arranged in the horizontal direction form a plurality of parallel horizontal rows, and the plurality of point light sources arranged in the vertical direction form a plurality of parallel vertical rows. The rows are perpendicular to the longitudinal rows and may include an angle (e.g., 60) in some embodiments. The annular arrangement may be such that the point sources are on circles of successively increasing radius centered on the centre of the screen.

In a non-limiting embodiment of the present invention, each of the light sensing units includes a red filter, a green filter and a blue filter, the red filter is located in the red identification area, the green filter is located in the green identification area, and the blue filter is located in the blue identification area.

In this embodiment, the light filters with different colors are arranged in the light sensing unit, so that the light rays with different colors can be identified. Specifically, a red filter, a green filter and a blue filter may be disposed to form a red identification region, a green identification region and a blue identification region.

In a non-limiting embodiment of the present invention, when the sensor element is a thin film transistor sensor, the area of the blue identification region is larger than the area of either one of the red identification region and the green identification region.

In the embodiment of the invention, because the thin film transistor sensor has weaker sensitivity to blue light, the area of the blue identification area can be set to be larger so as to acquire more blue light, and the quality of image acquisition is ensured.

It will be appreciated that in practical applications the area of the identification zone may be sized according to the sensitivity of the sensor component to different colours of light; specifically, the lower the sensitivity of the sensor component to a certain color of light, the larger the area of the identification region in which the color of light is set.

In one non-limiting embodiment of the present invention, the light source colors of the plurality of light source points are colored. That is, the colors of the light emitted from the plurality of light source points may include red, green, and blue, so that different color recognition regions in the sensor part may recognize different colors in the light.

In a non-limiting embodiment of the present invention, the light source unit may be a liquid crystal display, an active matrix organic light emitting diode display, or a micro light emitting diode display.

Referring to fig. 3, an embodiment of the invention further discloses an image scanning method. The image scanning method can be operated on the side of the electronic equipment, and the electronic equipment can comprise the fingerprint identification module.

The image scanning method may include the steps of:

step S301: illuminating light source points in a plurality of discrete point light source regions of the light source part, wherein non-illuminating light source points are arranged among the point light source regions in an array mode and are spaced;

step S302: the light of the luminous light source points totally reflected by the light-transmitting cover plate is obtained through the sensor part, and each photosensitive unit in the sensor part can identify red, green and blue in the light;

step S303: after the preset time interval, after the same position deviation is carried out on all the point light source areas, the luminous light source points in a plurality of separated point light source areas of the light source part are lightened iteratively, and the light rays of the luminous light source points totally reflected by the light-transmitting cover plate are obtained through the sensor part until the number of the position deviation reaches the preset number.

It should be noted that the sequence numbers of the steps in this embodiment do not represent a limitation on the execution sequence of the steps.

In specific implementation, a plurality of point light source regions are simultaneously lightened, a large amount of image information can be acquired each time, and then light data containing all images under the screen can be acquired through multiple times of position offset.

Specifically, the light emitting source points in the plurality of point light source regions may emit red, green, and blue light, respectively.

More specifically, referring to fig. 1, 2 and 3 together, each time the light source region is lit and light is obtained by the sensor part 103, that is, each time step S301 and step S302 are performed, since each light sensing unit in the sensor part 103 includes a red identification region, a green identification region and a blue identification region, each light sensing unit can identify red, green and blue colors in the light. In this case, a single scanning imaging process can obtain three images, namely a red image, a green image, and a blue image.

In a specific implementation, the operation of determining whether the preset number of times of execution is reached may be executed after the end of each light obtaining step and before the position shift operation, so as to avoid performing useless position shift, and further improve the fingerprint acquisition efficiency.

Further, the image scanning method may further include the steps of: and splicing according to the light ray data acquired by the optical sensor component to acquire image data.

In the embodiment of the present invention, because a single scanning process, that is, the process of executing step S301 and step S302, can only collect a part of fingerprints, the image corresponding to the light ray data obtained by multiple scanning (that is, the image obtained by executing step S303) can be subjected to stitching processing to obtain complete image data.

In practical application, in order to implement image stitching, the image data of the light acquired each time may be preprocessed, for example, the acquired image data is scaled, and invalid image data is removed, so as to acquire effective image areas of the light data acquired each time, and the effective image areas are stitched to obtain complete image data. Stitching is typically based on overlapping of identical portions of the image area, thereby extending different portions of the image area until the entire image is obtained.

In one non-limiting embodiment of the present invention, the direction of the position shift is from the light source point region to the adjacent point light source region; the distance of the position deviation is an integral fraction of the distance between the adjacent point light source regions.

In a specific implementation, the position offset is to acquire missing image information. To facilitate subsequent image stitching, the distance of each positional offset may be equal. And the preferred offset direction is that the point light source is offset to the adjacent point light source direction; the distance of the position deviation is an integral fraction of the spacing distance between the adjacent point light sources. For example, each time may be offset by one third or one eighth of the pitch of the centers of adjacent point sources. Therefore, the image data among the point light sources can be acquired at equal intervals, the same algorithm can be adopted for the image splicing algorithm, and the image splicing efficiency is higher.

In one non-limiting embodiment of the invention, the positional offset includes a lateral offset, a longitudinal offset, and a + -45 deg. directional offset

In a specific implementation, the array arrangement of the point light sources may include a transverse arrangement and a longitudinal arrangement which are perpendicular to each other, and accordingly, the position offset may include a transverse offset, a longitudinal offset, and a ± 45 ° direction offset; the transverse offset is an integer fraction of the transverse spacing distance of the adjacent point light source regions; the longitudinal offset is an integer fraction of the longitudinal spacing distance of the adjacent point light source regions; the +/-45-degree direction offset is an integral fraction of the distance between adjacent point light source areas in the direction. The total ray acquisition number is the number of lateral ray acquisitions times the number of longitudinal ray acquisitions. The more the number of positional shifts and the more the number of times of light acquisition, the more image information is acquired, but the longer the acquisition time is. In order to save time, the number of position shifts needs to be reduced as much as possible on the premise of satisfying the entire image stitching. This requires more image information to be acquired per light acquisition, which the fingerprint recognition module of this embodiment can satisfy. Taking 30 images as an example, the prior art needs to scan 30 times, but the present application only needs to scan 10 times, so that the collection efficiency is greatly improved.

In one non-limiting embodiment of the invention, the spot light source region is quasi-circular.

In an implementation, the appearance of the point light source also affects the presentation quality of the fingerprint image. In practical application, each point light source is square, and the combination of a plurality of point light sources cannot form a standard circle, but only can be a quasi-circle close to a circle. The determination of the quasi-circular point light point region can draw a circle by taking a certain point light source as a center, the point light sources in the circle can be all used as the quasi-circular point light sources, the point light sources on the circumference can be set to a preset area ratio, and if the ratio of the area of the circumference point light sources in the circle to the total area of the pixel points is greater than the preset area ratio, the point light sources are used as the point light source quasi-circular point light sources. The size of the circle determines the light intensity of the spot light source area and whether the sensor assembly can acquire a higher quality image. If the circle is too small, the spot light source area is too small, light shortage will be generated, if the circle is too large, the spot light source area is too large, and imaging quality will be affected. Different display panels also have different light source intensities, and the spot light source areas of different display panels also have different sizes. For a specific image imaging acquisition structure, the size of a point light source area can be acquired by adopting a manual repeated test mode, the size of the point light source area can be sequentially lightened from small to large, and then after a sensor part acquires image data, a minimum point light source area meeting the imaging quality is manually screened out.

In a non-limiting embodiment of the invention, the distance between two adjacent point light sources meets the condition that the point light source total reflection images collected by the sensor component are not in contact with and repeated.

In a specific implementation, the distance between the point light sources may affect the imaging quality or the calculation amount, for example, the distance between the point light sources is relatively short, so that in one light acquisition, images totally reflected by a single point light source may overlap, and then the overlapping portion is removed when the images are stitched, which may increase the workload of stitching the images each time. In order to avoid the overlapping of images obtained by different scanning, the distance between two adjacent point light sources meets the condition that the point light source total reflection images collected by the sensor component are not in contact and repeated. Further, the pitch of the point light sources may be a minimum value under the condition that the total reflection images of two adjacent point light sources do not contact and overlap. The minimum value can be obtained through manual multiple tests, for example, point light source total reflection images are obtained under different point light source intervals, and then the minimum value of the point light source intervals is observed when the reflection images meet the condition of no contact and no repetition. This minimum value can then be preset in a memory for running the method. The interval of pointolite can receive imaging structure hardware parameters's such as display panel, light sensor, printing opacity apron influence in the reality, and in practical application, the screen hardware parameter of a product generally can not change, to these specific screens, adopts the mode that artifical multiple test acquireed more direct and convenient.

In one non-limiting embodiment of the present invention, an image scanning apparatus is also disclosed. Referring to fig. 4, the image scanning apparatus 40 may include:

a light source lighting module 401, configured to light emitting light source points in a plurality of discrete point light source regions of the light source component, where the point light source regions are arranged in an array and have non-light emitting light source points at intervals;

a light acquiring module 402, configured to acquire, by the sensor component, light that is obtained by total reflection of the light source points through the transparent cover plate, where each photosensitive unit in the sensor component can identify red, green, and blue in the light;

the position shifting module 403 is configured to iteratively lighten the light source points in the multiple discrete point light source areas of the light source component after performing the same position shifting on all the point light source areas at intervals of a preset time, and obtain, through the sensor component, the light of the light source points totally reflected by the light-transmitting cover plate until the number of times of the position shifting reaches a preset number of times.

For more details of the operation principle and the operation mode of the image scanning apparatus 40, reference may be made to the description in fig. 1 to 3, which is not repeated here.

The embodiment of the invention also discloses a storage medium, which stores computer instructions, and the computer instructions can execute the steps of the method shown in the figure 3 when running. The storage medium may include ROM, RAM, magnetic or optical disks, etc. The storage medium may further include a non-volatile memory (non-volatile) or a non-transitory memory (non-transient), and the like.

The embodiment of the invention also discloses electronic equipment which can comprise a memory and a processor, wherein the memory stores computer instructions capable of running on the processor. The processor, when executing the computer instructions, may perform the steps of the method shown in fig. 3. The electronic device includes, but is not limited to, a mobile phone, a computer, a tablet computer and other terminal devices. Alternatively, the electronic device comprises the sensor module shown in fig. 1.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. The utility model provides a fingerprint identification module which characterized in that includes:

a light transmissive cover plate having opposing first and second faces;

a light source component located below the second face of the light transmissive cover sheet, the light source component including a plurality of light source points;

a sensor part located under the light source part, the sensor part including a plurality of light sensing units, each light sensing unit including a red identification area, a green identification area, and a blue identification area.

2. The fingerprint identification module of claim 1, wherein the plurality of light source points are arranged in an array.

3. The fingerprint identification module of claim 2, wherein the plurality of light source dots are arranged in an array selected from the group consisting of a transverse array, a longitudinal array, and a circular array.

4. The fingerprint identification module of claim 1, wherein each photosensitive unit comprises a red filter, a green filter and a blue filter, the red filter is located in the red identification area, the green filter is located in the green identification area, and the blue filter is located in the blue identification area.

5. The fingerprint identification module of claim 1, wherein the area of the blue identification region is larger than the area of either of the red identification region and the green identification region when the sensor component is a thin film transistor sensor.

6. The fingerprint identification module of claim 1, wherein the light source color of the plurality of light source points is colored.

7. The fingerprint identification module of claim 1, wherein the light source component is a liquid crystal display, an active matrix organic light emitting diode display, or a micro light emitting diode display.

8. The image scanning method of the fingerprint identification module according to any one of claims 1 to 7, comprising:

illuminating light source points in a plurality of discrete point light source regions of the light source part, wherein non-illuminating light source points are arranged among the point light source regions in an array mode and are spaced;

the light of the luminous light source points totally reflected by the light-transmitting cover plate is obtained through the sensor part, and each photosensitive unit in the sensor part can identify red, green and blue in the light;

after the preset time interval, after the same position deviation is carried out on all the point light source areas, the luminous light source points in a plurality of separated point light source areas of the light source part are lightened iteratively, and the light rays of the luminous light source points totally reflected by the light-transmitting cover plate are obtained through the sensor part until the number of the position deviation reaches the preset number.

9. The image scanning method according to claim 8, further comprising:

and splicing according to the light ray data acquired by the optical sensor component to acquire image data.

10. The image scanning method according to claim 8, wherein the direction of the positional shift is from the light source point region to the adjacent point light source region; the distance of the position deviation is an integral fraction of the distance between the adjacent point light source regions.

11. The image scanning method of claim 8, wherein the positional offsets include a lateral offset, a longitudinal offset, and a ± 45 ° directional offset.

12. The image scanning method of claim 8, wherein the spot light source region is a circle-like shape.

13. The image scanning method of claim 8, wherein the distance between two adjacent point light sources satisfies the condition that the total reflection images of the point light sources collected by the sensor unit do not contact and repeat.

14. A storage medium having stored thereon computer instructions, wherein the computer instructions are operable to perform the steps of the image scanning method of any one of claims 8 to 13.

15. An electronic device comprising a memory and a processor, the memory having stored thereon computer instructions executable on the processor, wherein the processor, when executing the computer instructions, performs the steps of the image scanning method of any of claims 8 to 13.