CN112861738A

CN112861738A - Optical module and electronic equipment

Info

Publication number: CN112861738A
Application number: CN202110186582.7A
Authority: CN
Inventors: 张�林
Original assignee: Beijing Jihao Technology Co Ltd
Current assignee: Beijing Jihao Technology Co Ltd
Priority date: 2021-02-10
Filing date: 2021-02-10
Publication date: 2021-05-28

Abstract

The application provides an optical module and electronic equipment relates to optical imaging technology field, can improve the imaging quality when optical module is applied to electronic equipment through each optical element's in the optical module setting. The optical module comprises a lens component and an image sensor arranged on the imaging side of the lens component, the imaging surface of the lens component, to be identified, of the object is an arc-shaped image surface, the photosensitive surface of the image sensor is arranged between the lowest point of the arc-shaped image surface and the highest point of the arc-shaped image surface, the optical module is used for fingerprint identification, and the object to be identified is a fingerprint. The optical module can balance the distance from the photosurface to the central area of the imaging surface and the distance from the photosurface to the edge area of the imaging surface, and the photosurface of the balanced image sensor receives the definition of an image, so that the definition of the image with biological information received by the image sensor is balanced, the biological information is extracted and analyzed from the clear image for identification, and the accuracy of the optical module for identifying the object to be identified is improved.

Description

Optical module and electronic equipment

Technical Field

The application relates to the technical field of optical imaging, in particular to an optical module and electronic equipment.

Background

With the development of portable terminal devices represented by mobile phones, the application of biometric technology is becoming more and more widespread and intensive. Taking electronic equipment as an example, fingerprint identification, fingerprint verification, face identification and the like are increasingly applied to the steps of screen awakening of display equipment and identity authentication of various programs, so that the safety of the display equipment and the flexibility of the use mode are improved.

In the prior art, an optical module is disposed in an electronic device, for example, the fingerprint module is disposed for fingerprint recognition, and for example, a lens module is disposed for face photographing or video image capturing, the optical module may be disposed in a recognition or collection area of a specific area of a display screen of the electronic device according to different positions of the recognition or collection, or in a recognition or collection area shared or individually disposed with an existing camera on the electronic device, the optical module disposed in the electronic device obtains a signal image toward the recognition or collection area, a user places a position (a face, a finger, a palm, etc.) with biometric information in the recognition or collection area, image capturing can be performed through the optical module, and the biometric information attached to the image is extracted and analyzed, thereby recognizing the biometric information.

The optical module generally includes a plurality of optical elements that need to be set and fixed according to a specific parameter such as a focal length, and after each optical element of the optical module is assembled and fixed inside the electronic device, the structure of the optical module is difficult to change and adjust, which affects the imaging quality of the image.

Disclosure of Invention

An object of the embodiments of the present application is to provide an optical module and an electronic device, which can improve the imaging quality of the optical module when applied to the electronic device through the arrangement of each optical element in the optical module.

An aspect of the embodiment of the application provides an optical module, including the lens part and set up in the image sensor of the formation of image side of lens part, the image plane that the object was treated to discernment by the lens part is arc image plane, and image sensor's photosensitive surface sets up between the minimum on arc image plane and the peak on arc image plane, and optical module is used for fingerprint identification, treats that the discernment object is the fingerprint.

Optionally, a distance T between the light sensing surface of the image sensor and the lowest point of the arc-shaped image surface satisfies:

and T is more than or equal to d/3 and less than or equal to d/2, wherein d is the distance between the lowest point of the arc-shaped image surface and the highest point of the arc-shaped image surface.

Optionally, the distance T between the light sensing surface of the image sensor and the lowest point of the arc-shaped image surface is d/2.

Optionally, a distance between the light sensing surface of the image sensor and the lowest point of the arc-shaped image surface is less than or equal to 5 μm.

Optionally, the lowest point of the arc-shaped image surface is an imaging position of the object to be recognized in the central field of view of the lens component, and the highest point of the arc-shaped image surface is an imaging position of the object to be recognized behind the lens component to the edge field of view of the lens component.

Optionally, the field angle of the lens component is equal to or greater than 120 °.

Optionally, the lens component comprises at least one lens.

Optionally, the lens component includes a first lens, a second lens, and a third lens sequentially arranged along the light transmission direction, where an object side of the first lens is a convex surface, and an image side of the first lens is a concave surface, or the object side of the first lens is a concave surface, and the image side of the first lens is a convex surface, and the second lens and the third lens are both biconvex lenses.

Optionally, the lens component further includes a lens barrel and a lens base connected to the lens barrel, the lens is fixedly disposed in a hollow structure in the lens barrel, and the image sensor is located at the bottom of the accommodating cavity of the lens base.

Optionally, the lens barrel is in threaded connection with the lens base, and the relative position between the lens barrel and the lens base is adjusted to change the position relation between the photosensitive surface and the arc-shaped image surface.

Optionally, an optical filter is further disposed between the lens component and the image sensor, and the optical filter is configured to filter out infrared light in the light beam transmitted through the lens component.

In another aspect of the embodiments of the present application, an electronic device is provided, which includes the optical module.

Optionally, electronic equipment still includes display panel, and optical module sets up under display panel, is provided with the fingerprint identification region on display panel, and optical module is located the regional below of fingerprint identification.

Optionally, the display panel is an OLED or a micro led.

The optical module and the electronic device provided by the embodiment of the application, the optical module can be configured in an image collecting area (such as a fingerprint identification area) of the electronic device, a lens component of the optical module receives a light beam carrying biological characteristic information and reflected by an object to be identified passing through the image collecting area and shapes and emits the light beam, the shaped and emitted light beam is received by a photosensitive surface of an image sensor and forms an image in the image sensor, when the lens component shapes and emits the light beam, an imaging surface of the object to be identified is an arc-shaped image surface formed by diverging the center of the object to be identified to the image sensor in a field angle range, the imaging surface is the lowest point of the arc-shaped image surface at the center of a main optical axis of the lens component and the farthest vertical distance with the lens component, and the imaging surface is the highest point of the arc-shaped image surface at the edge of the lens component, the position of the image receiving part is far away from the arc-shaped image surface for the definition of imaging, the definition of the image formed by the received light beams is poorer, and the photosensitive surface of the image sensor is a plane generally, so that the photosensitive surface of the image sensor is arranged between the lowest point of the arc-shaped image surface and the highest point of the arc-shaped image surface. Therefore, the distance from the photosensitive surface to the central area of the imaging surface and the distance from the photosensitive surface to the edge area of the imaging surface can be balanced, the definition of the image received by the photosensitive surface of the whole image sensor is balanced, the definition of the image with the biological information received by the image sensor is balanced, the biological information can be extracted and analyzed from the clear image to be recognized, and the accuracy of the optical module for recognizing the object to be recognized is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

FIG. 1 is a schematic diagram of an optical module according to some embodiments of the present disclosure;

FIG. 2 is a second schematic diagram of an optical module according to some embodiments of the present application;

FIG. 3 is a third schematic structural view of an optical module according to some embodiments of the present application;

FIG. 4 is a fourth schematic structural view of an optical module according to some embodiments of the present application;

FIG. 5 is a fifth schematic structural view of an optical module according to some embodiments of the present application;

FIG. 6 is a schematic block diagram of a lens component in an optical module according to some embodiments of the present application;

FIG. 7 is a sixth schematic structural view of an optical module according to some embodiments of the present application;

FIG. 8 is a schematic structural diagram of an electronic device of some embodiments of the present application;

FIG. 9 is a graph of optical simulation of an optical module according to some embodiments of the present application.

Icon: 10-a lens component; 101-an arc image surface; 11-lowest point; 12-highest point; 14-a lens barrel; 15-a lens base; 20-an image sensor; 201-central view field focusing plane, 202-edge view field focusing plane, 21-photosensitive surface; 30-an optical filter; 40-a display panel; t-the distance between the photosensitive surface of the image sensor and the lowest point of the arc-shaped image surface; d is the distance between the lowest point and the highest point of the arc image surface.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

In the description of the present application, it should be noted that the terms "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the application usually place when using, and are only used for convenience in describing the present application and simplifying the description, but do not indicate or imply that the devices or elements that are referred to must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

It should also be noted that, unless expressly stated or limited otherwise, the terms "disposed" and "connected" are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

In the prior art, image acquisition applied to electronic equipment is mostly realized by adopting an optical module, an optical module for performing feature recognition is arranged below a display screen of the electronic equipment, an operator attaches an object to be recognized to a specific position of the display screen, light beams emitted by the display screen irradiate and reflect on the object to be recognized, reflected light from the object to be recognized is integrated by a lens in the optical module arranged corresponding to the position and then enters a sensor for receiving, the sensor is usually arranged at the position of an arc-shaped image plane in a central field of view of the lens, namely the lowest point of the arc-shaped image plane, in order to preferentially ensure the image definition of the central field of view range, but for the whole receiving plane of the sensor, the farther away from the arc-shaped image plane in the direction of a main optical axis, the received image definition of the sensor is worse, and thus for the images received by the whole receiving plane of the sensor, the sharpness is not uniform everywhere, especially for the edge area of the received image, because the edge area is farthest from the arc-shaped image surface in the direction of the main optical axis, a great amount of characteristic information is probably lost due to the over-blurring of the image, and thus the accuracy of characteristic information extraction and processing analysis in the whole image is reduced.

Based on this, in an aspect of the embodiments of the present application, as shown in fig. 1, an optical module is provided, which includes a lens component 10 and an image sensor 20 disposed on an imaging side of the lens component 10, where the imaging surface of an object to be recognized by the lens component 10 is an arc-shaped image surface 101, and a light sensing surface 21 of the image sensor 20 is disposed between a lowest point 11 of the arc-shaped image surface 101 and a highest point 12 of the arc-shaped image surface 101.

As shown in fig. 1, the image sensor 20 is disposed on the imaging side of the lens component 10, a light beam which is irradiated from the other side of the lens component 10 on the object to be recognized and reflected by the object to be recognized and carries the characteristic information of the object to be recognized is incident on the imaging side of the lens component 10 after passing through the lens component 10, and the imaging surface of the lens component 10 on the object to be recognized is an arc-shaped image surface 101. It should be noted that the imaging plane in the embodiments of the present application may be understood as an image plane formed by a plurality of imaging points, where the received light beams all have a definition meeting the imaging standard.

Due to the limitation of practical production and processing conditions, the photosensitive surface 21 of the image sensor 20 is generally a plane, the plane photosensitive surface 21 is disposed between the lowest point 11 of the arc-shaped image plane 101 and the highest point 12 of the arc-shaped image plane 101, further, the light-sensing surface 21 may be arranged perpendicular to the direction of the main optical axis passing through the lens unit 10, and thus, on the photosensitive surface of the whole image sensor, although the image definition of the central area of the image sensor 20 is reduced to some extent, however, the sharpness of the image in the edge area of the image sensor 20 is enhanced, and originally, as the curvature of field becomes larger, the feature signal of the image in the edge area is too poor, which affects the accuracy of the recognition algorithm, and even effectively improves the problem that the recognition algorithm cannot work, and the sharpness of the received image from the center to the edge can be balanced, so as to obtain better image effect and accuracy of identifying the characteristics of the object to be identified in the image information.

It should be noted that, in the embodiment of the present application, a specific structure of the lens component 10 is not limited, the lens component 10 is configured to perform a converging and shaping process on an incident reflected light beam with characteristic information, and output the shaped light beam into the light sensing surface 21 of the image sensor 20, the lens component 10 may be a single optical element, or may be a module structure formed by mutually matching a plurality of optical elements, and when the lens component 10 is a structure formed by mutually matching a plurality of optical elements, it should be understood that a distance between the lens component 10 and the light sensing surface 21 of the image sensor 20 is based on an image-forming light emitting surface of the lens component 10. Furthermore, according to the size relationship between the light sensing surface 21 of the image sensor 20 and the light beam exiting range of the lens component 10, the position of the image sensor 20 or the lens component 10 can be adjusted to ensure that the light beam exiting range of the lens component 10 matches the size of the light sensing surface 21 of the image sensor 20.

The optical module of the embodiment of the present application can be applied to fingerprint recognition, and can also be applied to other image acquisition or biometric feature recognition in electronic equipment, for example, when the optical module of the embodiment of the present application is applied to electronic equipment, the optical module can be configured in a preset fingerprint recognition area on a display surface or other positions of the electronic equipment, and can be configured in a main camera or a front camera, and can be used for performing image acquisition, biometric feature extraction, analysis, and recognition, and the like on a face image, a palm print image, or other biometric images or videos acquired by the camera.

The optical module and the electronic device provided by the embodiment of the present application, the optical module can be configured in an image capturing area (such as a fingerprint recognition area) of the electronic device, the lens component 10 of the optical module receives a light beam carrying biometric information reflected by an object to be recognized passing through the image capturing area and shapes and emits the light beam, the shaped and emitted light beam is received by the photosensitive surface 21 of the image sensor 20 and forms an image in the image sensor 20, when the lens component 10 shapes and emits the light beam, an imaging surface of the object to be recognized of the emitted light beam is an arc-shaped image surface 101 formed by imaging the object to be recognized in a field angle range of the lens component 10, an image of the object to be recognized at a center of a main optical axis of the lens component 10 is a lowest point 11 of the arc-shaped image surface 101, a vertical distance from the lens component 10 is farthest, an image of the object to be recognized at an edge of the lens component 10 is a highest point 12 of, the closer the lens component 10 is, the more distant the image is from the arc-shaped image plane 101, the poorer the definition of the image is, and the light-sensing plane 21 of the image sensor 20 is generally a plane, so the light-sensing plane 21 of the image sensor 20 is disposed between the lowest point 11 of the arc-shaped image plane 101 and the highest point 12 of the arc-shaped image plane 101. Therefore, the distance from the photosensitive surface 21 to the central area of the imaging surface, the distance from the photosensitive surface 21 to the edge area of the imaging surface, the vertical distance between the received light beam and the arc-shaped image surface 101 on the photosensitive surface 21 of the image sensor 20 can be shortened, the definition of the image received by the photosensitive surface 21 of the whole image sensor 20 is balanced, the definition of the image with the biological information received by the image sensor 20 is balanced, the biological information is extracted and analyzed to be recognized from the clear image, and the accuracy of the optical module for recognizing the object to be recognized is improved.

In some preferred embodiments of the present application, as shown in fig. 2, the distance T between the photosensitive surface 21 of the image sensor 20 and the lowest point 11 of the arc-shaped image surface 101 satisfies:

d/3≤T≤d/2 (1)，

wherein d is the distance between the lowest point 11 and the highest point 12 of the arc-shaped image plane 101.

As shown in fig. 2, a plane tangent to the arc-shaped image plane 101 and perpendicular to the main optical axis is defined at the lowest point 11 of the arc-shaped image plane 101 as a central view field focusing plane 201, a clear image is formed on the central view field focusing plane 201 after a finger reflects and passes through the lens component 10, similarly, a plane intersecting with the arc-shaped image plane 101 and perpendicular to the main optical axis is defined at the highest point 12 of the arc-shaped image plane 101 as a peripheral view field focusing plane 202, a clear image is formed on the peripheral view field focusing plane 202 after a finger reflects and passes through the lens component 10, the lens component 10 is generally circular with the main optical axis as the center, then a plurality of highest points 12 of the arc-shaped image planes 101 are provided, and are connected to form a circular ring, the peripheral view field focusing plane 202 is a plane on which the circular ring is located, and thus it can be known that the central view field focusing plane 201 and the peripheral view field focusing plane 202 are in a parallel relationship, and the vertical distance between the central field focusing plane 201 and the lens component 10 is larger than the vertical distance between the marginal field focusing plane 202 and the lens component 10 by taking the direction of the main optical axis as a reference.

As shown in fig. 2, the distance between the lowest point 11 and the highest point 12 of the arc-shaped image plane 101 is d, that is, the distance between the central view field focusing plane 201 and the edge view field focusing plane 202, and the image sensor 20 is arranged such that the photosensitive surface 21 of the image sensor 20 satisfies the above formula (1), it can be understood that the image sensor 20 is moved upward from the lowest point 11 of the arc-shaped image plane 101 to a position between d/3 and d/2, when the photosensitive surface 21 of the image sensor 20 is arranged at a position corresponding to a range interval where d/3 is greater than or equal to T is greater than or equal to d/2, and the overall definition of the image carrying the biometric information received by the photosensitive surface 21 of the image sensor 20 is relatively balanced, the overall image can be as clear as possible, and not only the definition of the central region of the image can be ensured, but also the definition of the edge region of the, therefore, specific characteristic information at each point position can be extracted and analyzed from the clear image, and identity recognition of an operator can be performed.

In some preferred embodiments of the present application, as shown in fig. 3, the light sensing surface 21 of the image sensor 20 is spaced from the lowest point 11 of the curved image plane 101 by a distance T of d/2.

As shown in fig. 3, the light sensing surface 21 of the image sensor 20 is disposed at the d/2 position, and the vertical distance between the light sensing position of each light sensing unit on the whole light sensing surface 21 and the corresponding imaging point on the arc-shaped image surface 101 is less than or equal to d/2, so that each light sensing unit on the whole light sensing surface 21 can receive a relatively clear image, the problem that the characteristic information is extracted abnormally or cannot be extracted to related information due to the fact that light beams received at some positions or regions are too fuzzy is avoided, and the accuracy of extracting the biological characteristic information on the whole light sensing surface 21 is improved. In a popular way, after the definition of the light beam reaches a certain degree, the biological feature information contained in the light beam can be accurately extracted, even if the definition of the light beam at the position is further improved, the ability and the effect of further improving the accuracy of the extraction of the biological feature information do not exist, and if the definition of the light beam is too low, the extraction error or even the extraction failure of the biological feature information contained in the light beam at the position can be caused, so that the light sensing surface 21 of the image sensor 20 is arranged at a position where the distance T between the light sensing surface 21 and the lowest point 11 of the arc-shaped image surface 101 is equal to d/2, each light sensing unit on the whole light sensing surface 21 can receive a clearer image, and the accuracy of the extraction of the biological feature information in the acquired image can be effectively improved.

As shown in fig. 9, MTF (Modulation Transfer Function) is a reference value for a scientific resolution analysis of a lens, and the sharpness of a formed image can be measured by measuring the optical frequency. Generally, a higher MTF modulus value indicates a higher sharpness of the formed image.

In fig. 9, the black curve represents the MTF module curve of the central field area of the lens component 10 on the imaging side, the gray curve and the gray dotted line represent the MTF module curves of the peripheral field area of the lens component 10 on the imaging side in the meridional direction and the sagittal direction, respectively, the 0 point on the abscissa represents the position of the lowest point 11 of the curved image surface 101, assuming that a longitudinal scale parallel to the ordinate is provided in fig. 9, when the longitudinal scale moves from the 0 point to the left side, corresponding to the optical module, the light sensing surface 21 of the image sensor 20 moves up (moves toward the highest point 12 of the curved image surface 101), whereas when the longitudinal scale moves from the 0 point to the right side, corresponding to the optical module, the light sensing surface 21 of the image sensor 20 moves down, as can be seen from the trend curve in fig. 9, the MTF module value of the central field area at the position coinciding with the lowest point 11 of the curved image surface 101 is the highest, the central field of view region can achieve the best image definition at the lowest point 11 of the arc-shaped image plane 101, while the image definition of the edge field of view region is poor at this position, so if the photosensitive surface of the image sensor 20 is disposed at the lowest point 11 of the arc-shaped image plane 101 (corresponding to the position of 0 point in fig. 9), although the central field of view region can be made to have the best definition, the image definition of the edge field of view region is low. In the foregoing description, it has been mentioned that, after exceeding the required image definition standard, further improvement of the definition obtained too high does not have the capability and effect of further improving the accuracy of extracting the biometric information, and the lower image definition of the marginal field area may make the feature information in the acquired image unable to be extracted or make the feature information extraction error.

Therefore, as can be seen from fig. 9, in the process of moving the photosensitive surface 21 of the image sensor 20 upward, the image definition of the central view field region decreases to a certain extent, and the image definition of the edge view field region can be improved in the process of moving upward, so as to balance the two, it can be seen that the optical module in the embodiment of the present application satisfies the relationship: d/3. ltoreq. T.ltoreq.d/2, and particularly the overall image sharpness at a position where T is equal to d/2 is preferable.

In some preferred embodiments of the present application, the distance between the photosensitive surface 21 of the image sensor 20 and the lowest point 11 of the arc-shaped image surface 101 is less than or equal to 5 μm.

Generally, when the optical module according to the embodiment of the present application is applied to an electronic device for performing a biometric function, the optical module is mounted in the electronic device, and then the position of the optical module is fixed. Taking a mobile phone as an example, the mobile phone has a small overall structure, a circuit board, a camera, a display screen, a necessary circuit connection structure and other functional devices and structures need to be arranged in an internal space of the mobile phone, the overall structure of an optical module installed in the mobile phone is also very small, and a distance between a lowest point 11 and a highest point 12 of an arc-shaped image plane 101 imaged by the optical module is usually micron-sized, so that a distance between a photosensitive surface 21 of an image sensor 20 and the lowest point 11 of the arc-shaped image plane 101 is less than or equal to 5 μm, and it can be known from a trend curve in fig. 9 that when a moving distance of the photosensitive surface 21 of the image sensor 20 is too large, image definition in both a central view field region and an edge view field region is obviously reduced, thereby seriously affecting definition of received images.

In some preferred embodiments of the present application, the lowest point 11 of the arc-shaped image plane 101 is an imaging position of an object to be identified in the central field of view of the lens component 10, and the highest point 12 of the arc-shaped image plane 101 is an imaging position of an object to be identified in the peripheral field of view of the lens component 10.

The lens part 10 has a specific lens angle of view, and a light beam reflected by an object to be recognized within the lens angle of view can enter the lens part 10 from the entrance side, or only a light beam entering the lens part 10 within the lens angle of view can exit and be imaged, and a light beam entering the lens part 10 beyond an edge angle of view range may not exit due to total reflection, or may not be adopted due to an excessive aberration. In the embodiment of the application, the lowest point 11 of the arc-shaped image surface 101 coincides with the main optical axis, the lowest point 11 is the position where an object to be identified is imaged in the central field of view of the lens component 10, the peripheral field of view of the lens component 10 defines the position and height of the highest point 12 of the arc-shaped image surface 101, and a part beyond an annular area formed by connecting the highest points 12 is not taken as a light beam to be considered and processed in the scheme of the application even if the light beam enters the lens component 10 and is emitted from the imaging side, that is, the field angle of view of the lens component 10 defines the boundary of the arc-shaped image surface 101.

In some preferred embodiments of the present application, in the embodiments of the present application, the field angle of the lens component 10 is greater than or equal to 120 °, and the range of the field angle of greater than or equal to 120 ° enables light beams carrying biometric information in a range as large as possible to enter the lens component 10, and enter the photosensitive surface 21 of the image sensor 20 after being converged and shaped in the lens component 10, and the light beams exiting after being shaped by the lens component 10 have less graphical defects such as aberrations and distortions, and basically do not have adverse effects and changes on image acquisition and extraction and identification of biometric information in an image.

In some preferred embodiments of the present application, the optical module is used for fingerprint identification, and the object to be identified is a fingerprint.

As described above, the optical module according to the embodiment of the present application is applied to an electronic device, and the object to be recognized may be a fingerprint, a human face, a palm print, or other various objects having biometric information.

Taking a mobile phone as an example, the existing identification for an operator in the mobile phone generally includes fingerprint identification, palm print identification, or face identification based on optical image acquisition and processing analysis. Taking fingerprint identification as an example, the human fingerprint comprises concave-convex grains existing on the skin of the finger belly surface at the tail end of the finger, the grain shape of each human finger is different in the trend details, and two identical fingerprints are not available in the world, so that the determined unique individual can be identified by acquiring the image information of the fingerprint and extracting the unique biological fingerprint identification information belonging to the individual. Therefore, accurate and clear acquisition of fingerprint image information is extremely important for subsequent extraction of biological fingerprint identification information and guarantee of fingerprint identification accuracy.

When the optical module is used for fingerprint identification, it is corresponding, treat that the discernment object is the fingerprint, the operator covers the fingerprint identification who establishes on electronic equipment and predetermine regional with the finger, the optical module corresponds the regional window setting of fingerprint identification, the lens part 10 of optical module receives the light beam through the fingerprint reflection at the field angle within range at first, and assemble the plastic to the light beam, the light beam of outgoing after the plastic gets into image sensor 20's photosurface 21, receive and analysis processes by image sensor 20, extract the fingerprint characteristic information in the image.

In some preferred embodiments of the present application, the lens component 10 comprises at least one lens.

As shown in fig. 4, the lens component 10 shown in fig. 4 includes a lens, which may be a converging lens, or any other optical element capable of converging and shaping a light beam, for example, a double-convex lens, a meniscus lens with a light beam converging function, or the like.

When the lens component is used for fingerprint identification, the distance from the surface of at least one lens to a fingerprint is 2 mm-3.5 mm, and the lens component 10 can have a good fingerprint identification effect within the distance range.

Wherein, the distance of at least one piece of lens to fingerprint can be understood as the distance of the upper surface of at least one piece of lens to fingerprint, also can be understood as the distance of the optical center to fingerprint of the lens group that at least one piece of lens is constituteed, and technical staff in the art can carry out concrete definition as required or working custom to carry out corresponding setting and adjustment to the module structure of optical module according to the definition.

The lens component 10 is formed by a piece of lens, so that the whole structure of the lens component 10 and the structure of an optical module including the lens component 10 are compact, the installation precision is high, and the installation error is small. Since the lens assembly 10 has a small installation space in the optical module and needs to perform focusing and other processing on the optical path structure in a small space, in some preferred embodiments of the present application, the lens assembly 10 includes a first lens, a second lens, and a third lens that are sequentially arranged along the light transmission direction, where an object side of the first lens is a convex surface and an image side of the first lens is a concave surface, or the object side of the first lens is a concave surface and the image side of the first lens is a convex surface, and the second lens and the third lens are both double convex lenses.

As shown in fig. 5, the lens component 10 shapes the light beam by matching the first lens, the second lens and the third lens, and in the example shown in fig. 5, the object side of the first lens is a convex surface, and the image side of the first lens is a concave surface, and the second lens and the third lens are both double convex lenses, and this setting number and manner are that the lens component 10 has stronger adjusting capability for the light beam compared with a matching manner with a smaller number of lenses, and under the same condition, the larger number of lenses constituting the lens component 10, and after the multiple lenses are matched with each other, the smaller the radian of the arc-shaped image surface 101 imaged by the object to be recognized is, the closer to the plane. The curved image plane 101 approaches to a plane, and the difference between the sharpness of each image on the photosensitive surface 21 of the image sensor 20 may also be correspondingly reduced, so those skilled in the art should know that, when designing the number of lenses and the mutual setting relationship of the lens component 10, the lens component 10 needs to be selected by combining the difficulty of the matching setting of the lenses and the guarantee of the sharpness of the images, for example, three lenses (a first lens, a second lens and a third lens) are provided in the embodiment of the present application to constitute the lens component 10. In the present embodiment, the lens component 10 converges the light beam, so that the light beam can be incident on the photosensitive surface 21 of the image sensor 20 as completely as possible to collect complete image information. By adopting the lens component 10 consisting of three lenses, the whole structure of the lens component 10 and the structure of the optical module including the lens component 10 are simplified and compact, the installation precision is high, and the installation error is small.

In addition, it should be noted that the matching relationship among the first lens, the second lens and the third lens and the structural shape of the three lenses shown in fig. 5 are only an exemplary implementation manner, and in the embodiment of the present application, the number, the structural shape and the matching relationship of the lenses constituting the lens component 10 are not limited, and in order to perform the converging and shaping processing on the light beam, other lens forms may be provided according to a specific light path design as long as the formed lens component 10 is ensured to perform the converging and shaping functions on the whole passed light beam.

In some preferred embodiments of the present application, as shown in fig. 6, the lens component 10 further includes a lens barrel 14 and a lens holder 15 connected to the lens barrel 14, the lens is fixedly disposed in a hollow structure inside the lens barrel 14, and the image sensor 20 is located at the bottom of the accommodating cavity of the lens holder 15.

As shown in fig. 6, taking the lens component 10 including three lenses as an example for illustration and description, the lens component 10 includes a lens barrel 14 and a lens base 15 which are connected by screw threads, the first lens, the second lens and the third lens are all fixedly arranged in a hollow structure in the lens barrel 14, and by adjusting the up-down relationship of the lens barrel 14 in the lens base 15, the image plane position relationship between the first lens and the second lens fixed in the lens barrel, the third lens and the image sensor 20 can be adjusted.

In some preferred embodiments of the present application, as shown in fig. 6, the lens barrel 14 and the lens base 15 are connected by internal and external threads respectively, and the relative position between the lens barrel 14 and the lens base 15 can be conveniently and accurately adjusted by screwing, so that the positional relationship between the light-sensing surface 21 of the image sensor 20 and the arc-shaped image surface 101 can be changed.

In some preferred embodiments of the present application, as shown in fig. 7, a filter 30 is further disposed between the lens component 10 and the image sensor 20, and the filter 30 is used for filtering infrared light in a light beam.

Especially, when the optical module of the embodiment of the present application is applied to fingerprint identification, the infrared light in the light beam carrying the fingerprint information may cause the image sharpness to be affected and may affect the extraction of the biometric information in the image, therefore, the optical filter 30 is disposed in front of the light sensing surface 21 of the image sensor 20, and the filtering waveband of the optical filter 30 at least includes the infrared waveband, so that the light beam after being converged and shaped by the lens component 10 firstly filters the infrared light and then enters the light sensing surface 21 of the image sensor 20 to be received, thereby effectively reducing the adverse effect of the infrared light on image acquisition or identification.

In the aforementioned structure of the lens component 10 as shown in fig. 6, which includes the lens barrel 14 and the lens base 15 screwed with the lens barrel 14, the relationship between the arc-shaped image plane 101 imaged by the lens component 10 and the image sensor 20 is adjusted by adjusting the position of each lens in the lens component 10 in the direction of the main optical axis, a driving component may be connected to the lens barrel 14, and the driving component is driven by a driving signal sent by an existing controller in the electronic device to drive the lens barrel 14 to rotate so as to automatically adjust the relative positional relationship between the lens barrel 14 and the lens base 15.

The electronic equipment of the embodiment of the application can be a mobile phone, a notebook computer, an entrance guard, an intelligent door lock, an intelligent household appliance and the like. When the electronic device of the embodiment of the application is used for image acquisition or identity recognition of an object to be recognized, the optical module is arranged in the electronic equipment, the incident light beam carrying the biological characteristic information is processed and received by the optical module, because of the position setting relationship between the light-sensing surface 21 of the image sensor 20 and the arc-shaped image surface 101 imaged by the lens component 10 in the optical module, the vertical distance between the light beam received on the light-sensing surface 21 of the image sensor 20 and the arc-shaped image surface 101 is shortened, therefore, the definition of the image received by the photosensitive surface 21 of the whole image sensor 20 is balanced, the definition of the image with the biological information received by the image sensor 20 is balanced, the biological information can be extracted and analyzed from the clear image for identification, and the accuracy of the electronic equipment for identifying the identity of the object to be identified is improved.

In some preferred embodiments of the present application, as shown in fig. 8, the electronic device further includes a display panel 40, the optical module is disposed under the display panel 40, a fingerprint identification area is disposed on the display panel 40, and the optical module is located under the fingerprint identification area.

When the electronic device of the embodiment of the application is used for identifying a fingerprint to confirm the identity of an operator or achieve other purposes of image acquisition or image identification, as shown in fig. 8, a region between two dotted lines on the display panel 40 is represented as a fingerprint identification region, and an operator places a finger in the fingerprint identification region, because the optical module is disposed below the fingerprint identification region, and a coverage range of a field angle of the lens component 10 of the optical module can be understood as corresponding to the fingerprint identification region, therefore, a light beam reflected by a surface texture of the finger placed in the fingerprint identification region can be incident from the lens component 10 of the optical module and be converged and shaped, the processed light beam is incident into the photosensitive surface 21 of the image sensor 20 to perform extraction, analysis and identification of fingerprint information, and because the photosensitive surface 21 of the image sensor 20 can receive a fingerprint image with high definition, therefore, the accuracy of the electronic device of the embodiment of the application to fingerprint identification can be effectively improved, and under the same condition, because the quality of the fingerprint image is better, the processing speed of the image sensor 20 to the fingerprint image can be effectively improved.

In some preferred embodiments of the present application, when the optical module further includes the module holder 30, the module holder 30 of the fingerprint recognition device is fixedly disposed on the substrate of the display panel 40.

The display panel 40 generally includes a substrate and a display structure disposed on the substrate, and the display structure has a corresponding structure according to a display mode thereof, such as a liquid crystal display that needs a backlight to provide a light source, and a self-luminous display such as an LED. However, in any display mode, the display panel 40 includes a substrate and a frame housing disposed on the substrate and encapsulating the display structure, and when the optical module of the embodiment of the present application further includes the module bracket 30, the module bracket 30 may be fixed on the substrate, so that the optical module and the display panel 40 are fixed and correspond to the fingerprint identification area. Of course, it is also possible to use an existing structure on the substrate as the module holder 30, or to fix the optical module directly on the substrate and the frame housing for position fixing when the optical module does not include the module holder 30.

In some preferred embodiments of the present application, the display panel 40 is an OLED or a micro led.

The organic electroluminescence display panel is also called as OLED, the organic electroluminescence display panel is a self-luminous panel which performs electroluminescence through an internal structure, the display panel 40 in the embodiment of the present application adopts the organic electroluminescence display panel, when the organic electroluminescence display panel is used for fingerprint identification, light beams emitted by the organic electroluminescence display panel irradiate the surface of fingers covered at a fingerprint identification area, and the light beams reflected by the surface of the fingers enter the optical module to be received and processed, so that effective and rapid identification of fingerprints is realized. The OLED has good luminous intensity and working stability, is widely applied to electronic devices, and is called as a preferred display structure of the flexible electronic device by the stable performance of the OLED along with the development of flexible display.

The MicroLED is also called a micro light-emitting diode, a high-density integrated LED array formed by processing the LED by the micro and matrixing technology is realized, the distance between LED pixel points in the array is usually within the range of 10 micrometers, each LED pixel in the high-density integrated LED array can realize independent self-luminous control according to independent addressing drive, and the MicroLED as a new generation display device has the advantages of higher brightness, better luminous efficiency and lower power consumption compared with the OLED and has higher control precision. Micro leds are now used in many common electronic devices such as televisions, mobile phones, and tablet computers. The display panel 40 of the embodiment of the present application may further adopt a micro led, so that higher image control accuracy, display color saturation, and the like can be achieved.

When the electronic device of the embodiment of the present application is used for recognizing a fingerprint to confirm the identity of an operator or for other purposes, an operator places a finger in a fingerprint identification area, an optical module is arranged below the fingerprint identification area, the coverage range of the field angle of a lens component 10 of the optical module corresponds to the fingerprint identification area, light beams reflected by surface grains of the finger can be incident from the lens component 10 of the optical module and are subjected to convergence and shaping treatment, the treated light beams are incident into a photosensitive surface 21 of an image sensor 20 to extract, analyze and identify fingerprint information, since the photosensitive surface 21 of the image sensor 20 can receive the fingerprint image with higher definition, the accuracy of the electronic device for fingerprint identification is effectively improved, and, because the quality of the fingerprint image is better, the processing speed of the image sensor 20 for the fingerprint image can be effectively improved.

The above description is only an example of the present application and is not intended to limit the scope of the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. The optical module is characterized by comprising a lens component and an image sensor arranged on an imaging side of the lens component, wherein the imaging surface of an object to be identified by the lens component is an arc-shaped image surface, a photosensitive surface of the image sensor is arranged between the lowest point of the arc-shaped image surface and the highest point of the arc-shaped image surface, the optical module is used for fingerprint identification, and the object to be identified is a fingerprint.

2. The optical module as claimed in claim 1, wherein the distance T between the photosensitive surface of the image sensor and the lowest point of the arc-shaped image surface satisfies:

d/3≤T≤d/2；

and d is the distance between the lowest point of the arc-shaped image surface and the highest point of the arc-shaped image surface.

3. The optical module of claim 2, wherein the distance T between the photosensitive surface of the image sensor and the lowest point of the curved image surface is d/2.

4. The optical module of any one of claims 1-3, wherein a distance between a photosensitive surface of the image sensor and a lowest point of the curved image surface is less than or equal to 5 μm.

5. The optical module according to any one of claims 1 to 3, wherein the lowest point of the arc-shaped image plane is the imaging position of the object to be identified in the central field of view of the lens component, and the highest point of the arc-shaped image plane is the imaging position of the object to be identified in the edge field of view of the lens component.

6. The optical module of claim 5 wherein the lens component has a field angle of 120 ° or greater.

7. The optical module of any of claims 1-6 wherein the lens component comprises at least one lens.

8. The optical module as claimed in claim 7, wherein the at least one lens element includes a first lens element, a second lens element and a third lens element sequentially disposed along a light transmission direction, the first lens element has a convex object side and a concave image side, or the first lens element has a concave object side and a convex image side, and the second lens element and the third lens element are both biconvex lenses.

9. The optical module according to claim 7 or 8, wherein the lens component further includes a lens barrel and a lens holder connected to the lens barrel, the at least one lens is fixedly disposed in a hollow structure inside the lens barrel, and the image sensor is located at the bottom of the accommodating cavity of the lens holder.

10. The optical module of claim 9, wherein the lens barrel is screwed to the lens base, and adjusting the relative position between the lens barrel and the lens base changes the positional relationship between the photosensitive surface and the arc-shaped image surface.

11. The optical module according to any one of claims 1 to 10, wherein an optical filter is further disposed between the lens component and the image sensor, and the optical filter is configured to filter infrared light in the light beam transmitted through the lens component.

12. An electronic device comprising an optical module according to any one of claims 1-11.

13. The electronic device of claim 12, further comprising a display panel, wherein the optical module is disposed under the display panel, a fingerprint recognition area is disposed on the display panel, and the optical module is located under the fingerprint recognition area.

14. The electronic device of claim 13, wherein the display panel is an OLED or a micro led.