CN112307845A

CN112307845A - Optical detection device

Info

Publication number: CN112307845A
Application number: CN201910704590.9A
Authority: CN
Inventors: 林峰; 周扬; 朱文龙
Original assignee: Shenzhen Fushi Technology Co Ltd
Current assignee: Shenzhen Fushi Technology Co Ltd
Priority date: 2019-07-31
Filing date: 2019-07-31
Publication date: 2021-02-02

Abstract

The invention discloses an optical detection device which comprises a light guide unit, a detection module and a light source. The detection module receives a detection light beam emitted from the light guide unit, and the detection module is provided with a view field area on the first surface of the light guide unit. The light source projects a detection beam to a detection beam capable of being transmitted in the light guide unit in a total reflection manner to a preset area through the second surface of the light guide unit, and an overlapping area exists between the preset area and the view field area. When no finger of a user is in contact with the preset area, the detection light beam is totally reflected in the field of view area. When a user finger contacts the field of view area, the detection light beam is subjected to diffuse reflection at the fingerprint ridge contacting the field of view area, and the detection light beam is subjected to total reflection at the position opposite to the fingerprint valley in the field of view area. At least part of the detection light beams reflected diffusely passes through the light guide unit and is received by the detection module and converted into corresponding electric signals to obtain fingerprint information. The method has a good detection effect on the finger print under the screen.

Description

Optical detection device

Technical Field

The invention relates to the technical field of photoelectricity, in particular to an optical detection device for realizing fingerprint detection or other detections by utilizing optical imaging.

Background

With the technical progress and the improvement of living standard of people, users demand more functions and fashionable appearance for electronic products such as mobile phones, tablet computers, cameras and the like. At present, the development trend of electronic products such as mobile phones and the like is to have higher screen occupation ratio and have the functions of fingerprint detection and the like. In order to realize a full screen or a screen close to the full screen effect, the electronic product has a high screen occupation ratio, and the fingerprint detection technology under the screen is developed. However, for non-self-luminous displays such as liquid crystal display screens, the prior art has no better under-screen detection scheme.

Disclosure of Invention

In view of the above, the present invention provides an optical inspection apparatus capable of solving the problems of the prior art.

One aspect of the present invention provides an optical inspection apparatus, including a light guide unit including different first and second surfaces; the detection module is positioned below the light guide unit, the first surface is the surface of one side, back to the detection module, of the light guide unit, the detection module is used for receiving detection light beams emitted from the light guide unit, and the detection module is provided with a view field area on the first surface; the light source is used for projecting the detection light beams to the inside of the light guide unit through the second surface, the detection light beams entering the inside of the light guide unit can be transmitted in the light guide unit in a total reflection manner, a region where the detection light beams entering the inside of the light guide unit from the light source are transmitted and reach the first surface for the first time is defined as a preset region, an overlapping region exists between the preset region and the view field region, and the area proportion of the overlapping region in the view field region is greater than or equal to 30%; when no finger of a user is contacted on the preset area, the detection light beam is totally reflected in the field of view area; when a user finger contacts the field area, the detection light beams are subjected to diffuse reflection at the fingerprint ridges contacting the field area, and the detection light beams are subjected to total reflection at the positions, opposite to fingerprint valleys, of the field area, wherein at least part of the detection light beams subjected to diffuse reflection penetrate out of the light guide unit and are received by the detection module, and the detection module converts the received detection light beams into corresponding electric signals to obtain fingerprint information.

In certain embodiments, the predetermined area is the field of view area; or, the preset region is located in the field of view region, and the area of the preset region is smaller than that of the field of view region; or, the field of view region is located in the preset region, and the area of the field of view region is smaller than that of the preset region; or, there is an overlap between part of the preset region and part of the field of view region; defining a part of the preset area which is not overlapped with the field of view area as a non-overlapped area, wherein at least part or all of the non-overlapped area is adjacent to the light source compared with the overlapped area.

In some embodiments, when no finger of a user touches the field of view region, the detection beam capable of total reflection on the field of view region includes a detection beam which reaches the field of view region after being transmitted from the non-overlapping region through multiple total reflections, or/and a detection beam which reaches the overlapping region for the first time after entering the interior of the protective layer from the light source and satisfies total reflection at the overlapping region.

In some embodiments, the second surface is disposed opposite to the first surface, a region where the light source enters at the second surface is defined as a light entering region, and the detection light beam enters the light guide unit from the light entering region and is transmitted to the preset region; the light source is arranged in the light guide unit, and the light source is arranged in the light guide unit and is used for directly projecting the detection light beam to the overlapping area through the second surface.

In some embodiments, the light guide unit includes an upper surface and a lower surface that are disposed opposite to each other, the detection module is disposed below the lower surface and configured to receive a detection light beam emitted from the lower surface, and the first surface is the upper surface; the second surface is the lower surface, or the second surface is an inclined plane or a side surface of the light guide unit, and the inclined plane or the side surface is located between the upper surface and the lower surface.

In some embodiments, the light source includes a light emitting unit and a light converter, the light emitting unit is configured to emit a non-collimated detection light beam, and the light converter is configured to convert an angle at which the non-collimated detection light beam enters the light guide unit, so that the detection light beam can directly irradiate the preset area after entering the light guide unit and can be transmitted in the light guide unit by total reflection.

In some embodiments, the light converter is disposed between the light emitting surface of the light emitting unit and the second surface, or the light converter and the light guiding unit are integrally formed, and the light incident region of the detection beam on the second surface is a partial surface of the light converter.

In some embodiments, the optical detection apparatus further includes a display device, the display device includes a protective layer and a display module, the protective layer includes an upper surface and a lower surface that are opposite to each other, the display module is disposed on one side of the lower surface of the protective layer and is configured to perform image display, and the detection module is configured to receive a detection light beam emitted from the light guide unit through at least a portion of the display module; the upper surface of the protective layer is the first surface of the light guide unit.

In some embodiments, the protective layer includes a transparent region and a non-transparent region located in the transparent region, the display module is configured to emit a visible light beam through the transparent region, the light source is located in the non-transparent region in the light incident region of the second surface, and the wavelength of the detection light beam is different from the wavelength of the visible light beam.

In some embodiments, the display device further includes an optical adhesive for connecting the protective layer and the display module, and the light guide unit includes or is the protective layer, or the light guide unit includes or is the protective layer and the optical adhesive, or the light guide unit includes or is at least a part of the protective layer, the optical adhesive, and the display module.

In some embodiments, the protective layer includes a transparent substrate, the optical cement has a refractive index greater than or equal to a refractive index of the transparent substrate, and the refractive index of the transparent substrate is greater than a refractive index of air.

In some embodiments, the area of the display module for displaying the image is defined as a display area, and the area around the display area where the image cannot be displayed is defined as a non-display area; the field of view region is located directly above a local region of the display region.

The optical detection device has the beneficial effects that the optical detection device comprises a light guide unit, a detection module and a light source, wherein the light guide unit comprises a first surface and a second surface, the light source is used for providing a detection light beam, the detection light beam enters the light guide unit from the second surface of the light guide unit and can be transmitted in the light guide unit in a total reflection manner, and the detection light beam is diffusely reflected at the contact part of the first surface and the ridge. The detection module is located keeping away from of leaded light unit one side of first surface, the detection module can see through leaded light unit receives diffuse reflection's detection light beam converts the signal of telecommunication into, the signal of telecommunication can be used for fingerprint image to generate or fingerprint identification, and detection light beam diffuse reflection's region is just right detect the module. The optical detection device can be used for fingerprint detection, fingerprint optical imaging, fingerprint identification and the like under or in the screen. The optical detection device has a good fingerprint detection effect.

Drawings

FIG. 1 is a schematic view of one embodiment of an optical detection device of the present invention;

FIG. 2 is a schematic partial cross-sectional view of the optical detection device of FIG. 1;

FIG. 3 is a schematic partial cross-sectional view of a modified embodiment of the optical detection apparatus shown in FIG. 1;

FIG. 4 is a schematic partial cross-sectional view of a modified embodiment of the optical detection device shown in FIG. 1;

FIG. 5 is a schematic view, partly in cross-section, of an optical detection device;

FIG. 6 is a schematic view, partly in cross-section, of an optical detection device;

FIG. 7 is a schematic partial cross-sectional view of one embodiment of an optical detection device of the present invention;

FIG. 8 is a schematic perspective view of a portion of the optical detection device of FIG. 7;

FIG. 9 is a further partial cross-sectional schematic view of the optical detection device shown in FIG. 7;

FIG. 10 is a schematic partial cross-sectional view of a modified embodiment of the optical detection device shown in FIG. 7;

FIG. 11 is a schematic partial cross-sectional view of a modified embodiment of the optical detection device shown in FIG. 7;

FIG. 12 is a schematic partial cross-sectional view of one embodiment of an optical detection device of the present invention;

FIG. 13 is a schematic partial cross-sectional view of one embodiment of an optical inspection device of the present invention.

Detailed Description

In the detailed description of the embodiments of the invention, it will be understood that when a substrate, a sheet, a layer, or a pattern is referred to as being "on" or "under" another substrate, another sheet, another layer, or another pattern, it can be "directly" or "indirectly" on the other substrate, the other sheet, the other layer, or the other pattern, or one or more intervening layers may also be present. The thickness and size of each layer in the drawings of the specification may be exaggerated, omitted, or schematically represented for clarity. Further, the sizes of the elements in the drawings do not completely reflect actual sizes.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Further, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of embodiments of the application. One skilled in the relevant art will recognize, however, that the subject technology can be practiced without one or more of the specific details, or with other structures, components, and so forth. In other instances, well-known structures or operations are not shown or described in detail to avoid obscuring the focus of the application.

Referring to fig. 1 to 2, fig. 1 is a schematic view of an optical detection device 1 according to an embodiment of the present invention, and fig. 2 is a partial cross-sectional view of the optical detection device 1 along a line P-P in fig. 1. The optical detection device 1 includes a light guide unit 100, a detection module 19, a light source 16, and a light guide unit 100. The detection module 19 is at least partially located below the light guide unit 100. The light source 16 is located below the light guide unit 100.

The light guide unit 100 includes a first surface and a second surface, which are different surfaces of the light guide unit 100. In this embodiment, the first surface is an upper surface of the light guide unit 100, the second surface is a lower surface of the light guide unit 100, and the upper surface and the lower surface are disposed oppositely. Alternatively, in other or modified embodiments, the second surface may be a slope or a side surface of the light guide unit 100. Optionally, the first surface is a plane, or a main body of the first surface is a plane, and an edge portion of the main body is a curved surface. The light source 16 is configured to project the detection light beam 101 through the second surface of the light guide unit 100 to at least one predetermined area P1 of the first surface. The detection module 19 has a field of view region V1 on the first surface of the light guide unit 100. The preset region P1 is a region where the detection light beam 101 enters the light guide unit 100 from the second surface of the light guide unit 100 and then reaches the first surface for the first time through transmission. The field of view region V1 is the touch region of the user's finger on the first surface during fingerprint detection, and is also the portion of the first surface that is located in the largest area where the detection module 19 can receive the light beam. The first surface of the light guiding unit 100 is a surface directly contacted by a finger of a user during fingerprint detection, and is usually the outermost surface of the optical detection device 1 or an electronic product including the optical detection device 1. For convenience of description, the preset area P1 may also be regarded as an area directly irradiated by the detection beam 101 on the first surface.

Part or all of the detection light beams 101 meet the condition of total reflection transmission in the light guide unit 100, and when no finger of a user touches the preset area P1, the detection light beams 101 are totally reflected in the view field area V1. When a user's finger touches the field of view region V1, the detection beam 101 is diffusely reflected at the fingerprint ridge 1100 touching the field of view region V1, and the detection beam 101 is totally reflected at the position where the field of view region V1 is opposite to the fingerprint valley 1200. At least part of the detection light beam 101 subjected to diffuse reflection passes out of the light guide unit 100 to be received by the detection module 19, and the detection module 19 converts the received detection light beam 101 into a corresponding electric signal to obtain fingerprint information.

The detection module 19 is located below the second surface of the light guide unit 100, and the detection module 19 is configured to receive the detection light beam 101 emitted from the second surface of the light guide unit 100, and convert the received detection light beam 101 into a corresponding electrical signal to obtain fingerprint information.

In this embodiment, the preset region P1 is a view field region V1 of the detection module 19 on the upper surface of the light guide unit 100. In other or modified embodiments, the preset region P1 may be located in the viewing region V1, or the preset region P1 may partially overlap with the viewing region V1, or there is no overlap between the preset region P1 and the viewing region V1. When there is no overlap between the preset region P1 and the field of view region V1, the preset region P1 and the field of view region V1 are disposed at intervals or in close proximity. The embodiment of the present invention is not limited thereto.

Optionally, in some embodiments, the optical detection apparatus 1 is applied in an electronic product, the electronic product includes a center line from a top end to a bottom end thereof, and the center of the field of view region V1 is located on or near the center line.

Optionally, in some embodiments, the optical detection apparatus 1 is applied to an electronic product, the electronic product includes a central line from a top end to a bottom end thereof, and the center of the predetermined area P1 is located on or near the central line.

Optionally, in some embodiments, the optical detection apparatus 1 is applied in an electronic product, and the interval between the field of view region V1 and the bottom edge of the electronic product is 3 to 20 mm, or 3 to 15 mm, or 3 to 10 mm. Further optionally, in some embodiments, the light source 16 and the detection module 19 are both disposed near a bottom edge of the electronic product, the light source 16 is closer to the bottom edge of the electronic product than the detection module 19, and a horizontal distance between the detection module 19 and the light source 16 is 10 to 15 mm.

Optionally, in some embodiments, when there is an overlap between the preset region P1 and the field of view region V1, the overlapping portion is defined as an overlapping region. The detection light beam 101 with the shortest distance from the light incident region 113 to the overlapping region satisfies the condition of total reflection transmission in the light guide unit 100, or the detection light beam 101 projected directly to the overlapping region by the light source 16 through the second surface can be transmitted by total reflection in the light guide unit 100.

In this embodiment, the second surface of the light guide unit 100 has a light incident area 113 for the detection light beam 101 to enter. An included angle between a shortest straight line between the light incident region 113 and the preset region P1 and a normal of the upper surface of the light guide unit 100 is not less than a critical angle at which the detection light beam realizes total reflection transmission in the light guide unit 100. The light incident region 113 of the detection beam 101 on the second surface is planar or non-planar.

Optionally, in some embodiments, a shortest straight line exists between the light incident region 113 and the overlapping region, and an included angle between the shortest straight line and a normal of the overlapping region is not less than a critical angle at which the detection beam is transmitted in a total reflection manner in the light guide unit 100, or a detection beam at a shortest distance from the light incident region 113 to the overlapping region satisfies a condition at which the detection beam is transmitted in a total reflection manner in the light guide unit 100, or a detection beam directly projected to the overlapping region by the light source 16 through the second surface satisfies a condition at which the detection beam is transmitted in a total reflection manner in the light guide unit.

Optionally, in some embodiments, for example and without limitation, an included angle between a shortest straight line between the light incident region 113 and the field of view region V1 and a normal of the first surface of the light guide unit 100 is not less than a critical angle at which the detection light beam 101 realizes total reflection transmission in the light guide unit 100.

Optionally, in some embodiments, for example and without limitation, an included angle between a shortest straight line between the light incident region 113 and an overlapping region of the preset region P1 and the field of view region V1 and a normal of the first surface of the light guide unit 100 is not less than a critical angle at which the detection light beam 101 realizes total reflection transmission in the light guide unit 100.

Alternatively, in some embodiments, it is understood that the light source 16 may be disposed at any position of the optical detection apparatus 1 as long as the detection light beam 101 emitted by the light source 16 can reach the light-entering region 113. For example, but not limited to, the light source 16 may be disposed below the detection module 19 and conduct the emitted detection light beam 101 to the light-entering region 113 through a light-guiding element, which may be a solid light-guiding structure, and/or a hollow light-guiding structure. Alternatively, in some embodiments, the detection light beam 101 emitted by the light source 16 may directly reach the light-entering region 113 without passing through a light-guiding element.

In this embodiment, the light source 16 is configured to project the detection light beam 101 to at least one preset area P1 on the upper surface of the light guide unit 100 through the lower surface of the light guide unit 100. The detection beam 101 is a non-collimated beam. And, a part or all of the detection light beam 101 projected to the preset area P1 satisfies a condition of total reflection transmission in the light guide unit 100. When no finger or other detection object touches the preset area P1, the detection light beam 101 is totally reflected in the field of view area V1. In fingerprint detection, the ridges 1100 of the finger fingerprint 1000 contact the field of view region V1, and the valleys 1200 have a spacer with the corresponding portion of the field of view region V1. The spacer may be air, water, or the like. Generally, the spacer between the valleys of the fingerprint and said predetermined area P1 is air. Of course, the spacer between the valleys of the fingerprint and said predetermined area P1 may be liquid or otherwise, due to perspiration of the finger or the like. The embodiment of the present invention is described with the spacer as air, and it is understood that other possible spacers also fall within the scope of the present invention, and the embodiment of the present invention is not limited thereto.

It is to be understood that although for illustrative purposes the present application is generally described in the context of fingerprints as an example, the optical detection apparatus 1 is not limited to the detection of fingerprints, and the detection object of the optical detection apparatus 1 can be any object to be imaged. Generally, a test object may have various characteristics including a biological characteristic. It should be noted that, as an example, the optical detection device 1 of the present invention is described with a finger fingerprint as a detection object, and it is understood that lines such as palm, toe, palm print, skin surface texture and the like can also be used as features of the detection object of the present invention or an external object to be detected.

The fingerprint 1000 has ridges 1100 and valleys 1200, and the ridges 1100 contact the upper surface of the light guide unit 100 (i.e. the outer surface of the optical detection device 1 touched by the user) during detection. In contrast, the valleys 1200 do not contact the upper surface of the light guide unit 100 with a spacer between the valleys 1200 and the upper surface. It will be appreciated that the fingerprint 1000 may have substances thereon, such as stains, ink, moisture, etc., and that embodiments of the present invention are equally applicable to optical imaging of the fingerprint 1000 having such substances.

The detection beam 101 is diffusely reflected at the ridge 1100 of the fingerprint 1000. The detection module 19 can receive the detection light beam 101 returned from the ridge 1100 through the light guide unit 100. The detection module 19 receives the detection beam 101 and converts the detection beam into an electrical signal. The electrical signal can be used for optical imaging of the fingerprint 1000 or fingerprint detection. The detection light beam 101 irradiated at the field-of-view region V1 opposite to the valley is totally reflected.

In this embodiment, the preset region P1 is a view field region V1 of the detection module 19 on the upper surface of the light guide unit 100. Alternatively, in other or modified embodiments, the preset region P1 may be a part of the field of view region V1, which may be located in the field of view region V1. Alternatively, in other or modified embodiments, the preset region P1 may overlap or not overlap with the field of view region V1. It should be noted that the overlapping of the field-of-view region V1 and the preset region P1 described in the present application includes: the field-of-view region V1 and the preset region P1 completely coincide, the field-of-view region V1 is a partial region of the preset region P1, the preset region P1 is a portion of the field-of-view region V1, or the preset region P1 and the field-of-view region V1 have a common partial region.

It should be noted that the drawings of the present invention are only exemplary, and actually, the size of the ridges and valleys of the fingerprint is very small (about 300 to 500 micrometers), and the size of the area of the fingerprint to be detected in the fingerprint detection is about 4 mm × 10 mm, or a larger area.

The lower surface of a portion of the light guide unit 100 has a light entrance region 113, and the detection light beam 101 emitted by the light source 16 enters the light guide unit 100 through the light entrance region 113. At least a part of the detection light beam 101 entering the light guide unit 100 from the light incident region 113 directly irradiates and covers the preset region P1. In this embodiment, all of the detection light beams 101 irradiated to the preset area P1 satisfy the condition of total reflection transmission in the light guide unit 100.

In the present embodiment, the light incident region 113 is located on the lower surface of the light guide unit 100, but the present invention is not limited thereto, and the light incident region 113 may be located at other positions of the light guide unit 113. For example, but not limited to, the light incident region 113 may be located on one side surface of the light guide unit 100, and the side surface of the light guide unit 100 may be connected to an upper surface and a lower surface thereof. Alternatively, the light incident region 113 may be located on an inclined surface of the light guide unit 1000, and the inclined surface of the light guide unit 100 may be located at an edge portion of the light guide unit 100 to have a certain inclination angle with respect to an upper surface or a lower surface thereof. Therefore, the light incident region 113 may be located at any suitable position of the light guide unit 100, which is not limited in the present invention.

Alternatively, in other or modified embodiments, a portion of the detection light beam 101 directly irradiated to the preset region P1 satisfies a condition of total reflection transmission in the light guide unit 100, for example, but not limited to, another portion of the detection light beam 101 is refracted and/or reflected on the preset region P1.

Further alternatively, not less than 20% -30% of the detection light beam 101 irradiated to the preset region P1 satisfies the condition of total reflection transmission within the light guiding unit 100. In this case, for example, but not limited to, the total power of the light source 16 may be 90mW (milliwatt) to 120mW, and when the light source includes 3 light emitting elements, the power of each light emitting element may be 30mA (milliampere) to 40mA, and the current may be 70 mA. Of course, the proportion of the detection light beam 101 which irradiates the preset region P1 and satisfies the condition of total reflection transmission may be greater than 30%, 40% or 50%, and the current or power of the light source 16 may be appropriately adjusted accordingly, so that the power consumption and heat generation can be reduced. When the proportion of the detection beam 101 which is irradiated to the preset area P1 and satisfies the total reflection transmission condition is less than 20% or 10%, the current or power of the light source 16 needs to be increased accordingly to satisfy the light intensity required for optical imaging of the fingerprint.

Alternatively, in another or modified embodiment, part or all of the detection beam 101 entering the light guide unit 100 from the light incident region 113 satisfies the condition of total reflection and transmission in the light guide unit 100. The conditions of the total reflection transmission include: the detection beam 101 is totally reflected at a first surface of the light guide unit 100 where the ridge of the fingerprint is not in contact, and totally reflected at a second surface of the light guide unit 100. The detection light beam 101 is diffusely reflected at a location where the first surface of the light guiding unit 100 contacts the ridge 1100 of the fingerprint 1000.

Optionally, in some embodiments, when the first surface and the second surface are not disposed opposite to each other, for example but not limited to, the first surface is an upper surface of the light guide unit 100, and the second surface is a side surface of the light guide unit 100, in this case, the light guide unit 100 further includes a third surface opposite to the first surface. The detection light beam 101 enters the light guide unit 100 from the second surface, and can be totally reflected on the first surface and the third surface, and then is totally reflected and transmitted in the light guide unit 100.

In this embodiment, the detection light beam 101 entering the light guide unit 100 is a non-collimated light beam or a non-parallel light beam. The non-collimated light detection light beam 101 comprises a plurality of detection light rays, and the included angle of at least two detection light rays is not less than 10 degrees, 15 degrees, 20 degrees and 25 degrees.

In this embodiment, the detection beam 101 is invisible light, including but not limited to near infrared light. The near infrared light is, for example, a light beam having a wavelength of 750 to 2000nm (nanometers). By way of example, but not limitation, the detection beam 101 is near infrared light having a wavelength of 800-1200 nm.

Illustratively, the light guide unit 100 may include a transparent material, such as, but not limited to, transparent glass, a transparent polymer material, any other transparent material, and the like. The light guide unit 100 may have a single-layer structure or a multi-layer structure.

It should be noted that the detection module 19 in this embodiment receives the detection beam 101 diffusely reflected at the ridge 1100 and is used for optical imaging of the fingerprint. However, the invention is not limited thereto, and the detection module 19 may receive other light beams with fingerprint feature information for imaging or detection. For example, but not limiting of, the detection module 19 may receive the detection beam 101 directly reflected from the surface of the user's finger (including the ridges and/or valleys of the fingerprint) and used for fingerprint detection; for example, but not limited to, the detection module 19 may receive visible light and/or invisible light in the external environment reflected by the user's finger and be used for fingerprint detection; for example, but not limited to, the detection module 19 may receive visible light and/or invisible light in an external environment transmitted by a user's finger and be used for fingerprint detection; for example, but not limited to, the detection module 19 may receive visible light and/or invisible light emitted by a user's finger and be used for fingerprint detection. Further, the fingerprint detection may be performed for other detection objects, and the characteristic information of the detection object may be obtained by an optical imaging method. Therefore, although the embodiment of the present invention is described with reference to receiving the diffusely reflected detecting light beam 101, other possible light beams for optical imaging of a fingerprint are within the scope of the present invention.

Referring to fig. 3, an optical detection device 1A is a modified embodiment of the optical detection device 1, the structure of the optical detection device 1A is substantially the same as that of the optical detection device 1, and the reference numerals of the elements in fig. 3 and fig. 2 are the same for convenience of description. The difference is that the preset region P1 and the field of view region V1 of the optical inspection apparatus 1A partially overlap, as shown in fig. 3, the overlapping region is denoted by Q1, and the preset region P1 includes an overlapping region Q1 and an irradiation region that is closer to the light source 16 than the overlapping region Q1. The area of the overlap region Q1 is greater than or equal to 30% of the area of the field of view region V1 and less than or equal to 100% of the area of the field of view region V1. For example, but not limiting of, the proportion of the area of the overlap region Q1 to the area of the field of view region V1 is 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 90%, 95%, 100%.

When no finger of the user touches the field of view region V1, the detection light beam 101 capable of undergoing total reflection on the field of view region V1 includes a detection light beam transmitted to the field of view region V1 by multiple total reflections from a non-overlapping region (a region where the preset region P1 does not overlap with the field of view region V1 is a non-overlapping region), or/and a detection light beam 101 which enters the light guide unit 100 from the light source 16 and then reaches the overlapping region Q1 for the first time and satisfies total reflection at the overlapping region Q1.

There is a shortest straight line between the light incident region and the overlapping region Q1, and an included angle between the shortest straight line and a normal of the overlapping region is not less than a critical angle at which the detection light beam is transmitted in a total reflection manner in the light guide unit, or a shortest distance from the light incident region to the overlapping region Q1 satisfies a condition at which the detection light beam is transmitted in a total reflection manner in the light guide unit 100, or the detection light beam projected directly from the light source 16 to the overlapping region Q1 through the second surface satisfies a condition at which the detection light beam is transmitted in a total reflection manner in the light guide unit 100.

Part or all of the detection light beam 101 irradiated onto the preset region P1 other than the overlap region Q1 can reach the field of view region V1 (including the overlap region Q1 of the field of view region V1 and the preset region P1 and the region where the field of view region V1 does not overlap the preset region P1) after being transmitted by total reflection. When the user's finger touches the field of view region V1: the detection light beam 101 entering from the light incident region 113 and reaching the overlap region Q1 for the first time is diffusely reflected at the ridge 1100 of the fingerprint and totally reflected at the opposite valley 1200 of the overlap region Q1; the detection light beam 101 transmitted from the portion outside the overlapping area of the preset area P1 to the field of view area V1 by total reflection also undergoes diffuse reflection at the ridges 1100 of the fingerprint and total reflection at the overlapping area Q1 opposite to the valleys 1200. The detection module 19 receives the diffusely reflected detection beam 101 at a side of the light guide unit 100 away from the first surface and is used for fingerprint imaging. The first surface is an outermost surface of the light detecting device 1, and the detecting module 19 is located on a side of the light guiding unit 100 opposite to the outer side.

Referring to fig. 4, an optical detection device 1B is a modified embodiment of the optical detection device 1, the structure of the optical detection device 1B is substantially the same as that of the optical detection device 1, and the reference numerals of the elements in fig. 4 and fig. 2 are the same for convenience of description. The difference is that there is no overlap between the preset area P1 and the field of view area V1 of the optical inspection apparatus 1A, and part or all of the inspection light beam 101 irradiated onto the preset area P1 can be transmitted to the field of view area V1 by total reflection. When the user's finger touches the field of view region V1: the detection light beam 101 irradiated on the preset region P1 can be transmitted to the view field region V1 through total reflection, and the view field region V1 is a region touched by a finger of a user. The detection beam 101 is diffusely reflected at the ridges 1100 of the fingerprint and totally reflected at the overlapping areas relative to the valleys 1200. The detection module 19 receives the diffusely reflected detection beam 101 at a side of the light guide unit 100 away from the first surface and is used for fingerprint imaging. The first surface of the light guide unit 100 is a surface touched by a user, and the detection light beam 101 can directly irradiate the view field area V1 by projecting the detection light beam 101 into the light guide unit 100, or the detection light beam 101 is transmitted to the view field area V1 by total reflection. When the fingerprint is detected, the user's finger touches the field of view region V1, and the detection beam 101 is diffusely reflected at the ridge 1100 of the fingerprint. The detection module 19 is disposed under the light guide unit 100 just opposite to the view field area V1, and the detection module 19 receives the detection light beam 101 that is reflected diffusely and then passes through the light guide unit 100 and converts the detection light beam into an electrical signal. The area of the perpendicular projection of the detection module 19 on the first surface is smaller than the area of the field of view region V1, or the perpendicular projection of the detection module 19 on the first surface is located within the field of view region V1. The optical detection device 1 images by collecting the diffusely reflected detection light beam 101, thereby realizing fingerprint detection and identification. The diffusely reflected detection light beam 101 can enter the detection module 19 at different incident angles, and the detection module 19 has a small volume.

Of course, collimated light may also be used as the detection beam in some embodiments. It will be appreciated that if a collimated beam is used as the detection beam, this results in the width of the predetermined area being the same as the width of the light entrance area. Since electronic products capable of displaying images are mainly used for full-screen and narrow-frame applications, the area of the optical detection apparatus 1 for displaying images can be referred to as a visible area, and the portion around the visible area where no image is displayed is referred to as a frame area. The frame area is narrow, and the light-entering area 113 is generally located in the frame area of the optical detection apparatus 1 so as not to affect the image display of the visible area, and thus the width of the light-entering area 113 is also very small. Accordingly, the width of the preset region P1 is very small, and the viewing field region V1 is generally a rectangle with 5 mm × 5 mm or a circular region with a radius of 2 to 5 mm. Due to the parallel transmission characteristics of collimated light, at this time, the following problems are likely to occur: there are some positions on the field of view region V5 where no detection beam can directly impinge, nor can the detection beam reach the field of view region V5 after total reflection. As shown in fig. 5, the presence of the partial area of the field of view region V5 where no detection beam is irradiated results in the partial fingerprints corresponding to these positions not being detected. Therefore, although the detection beam of collimated light can also detect or optically image a fingerprint, it has a great disadvantage that the detection efficiency and the imaging quality for a fingerprint are inferior to those of the detection beam 101 of non-collimated light.

Of course, in other embodiments, a non-collimated detection beam 101 may also be used. Please refer to fig. 6. The non-collimated detection beam 101 passes through the optical light guide unit 100 after being totally reflected, and can be further received by a detection module, at this time, it is equivalent to the optical detection device 1 receiving the totally reflected detection beam 101 for imaging and detection. For example, the non-collimated detection light beam 101 totally reflects on the upper surface of the light guide unit 100, and then passes through the light guide unit 100 of the optical detection apparatus 1 and is further received by the detection module. When detecting a fingerprint, a user touches the preset area P1 directly illuminated by the detection light beam 101 on the upper surface of the light guide unit 100 with a finger, and the detection light beam 101 illuminated on the ridge 1100 is diffusely reflected and is not received by the detection module or the intensity of the detection light beam received by the detection module is smaller than that of the incident light. The detection light beam 101 irradiated to other positions is totally reflected and is emitted out through an optical element attached to the lower surface of the light guide unit 100, and the total reflection light intensity received by the detection module is the same as that of the incident light, so that an image with light and shade contrast of the fingerprint is obtained. However, in these embodiments, an optical element needs to be disposed on the lower surface of the light guide unit 100, so that the detection beam 101 can be emitted from the lower surface after being totally reflected on the upper surface of the light guide unit 100. The provision of the optical element necessarily leads to an increase in the cost and an increase in the assembly complexity of the optical detection apparatus 1. Moreover, in these embodiments, since the detection light beam 101 is non-collimated light, and has a certain divergence angle when it is projected on the preset region P1 on the upper surface of the light guide unit 100, the width of the preset region P1 is larger than the width of the light incident region 113. Accordingly, the reflected light of the detection light beam 101 after being totally reflected in the preset area 15 also has a certain divergence angle, and therefore, it can be understood that the detection light beam 101 totally reflected to the lower surface of the light guide unit is emitted from the lower surface, and the emitted detection light beam 101 correspondingly has an emission area with a width larger than that of the preset area P1 on the lower surface. Therefore, the fingerprint image formed by the detection beam 101 totally reflected to the lower surface and emitted will have a relatively serious amplification phenomenon, thereby causing the fingerprint image to be distorted. In addition, the area of the emitting area of the detection light beam 101 on the lower surface of the light guide unit 100 is larger, and accordingly, a detection module for receiving the emitted detection light beam 101 needs a larger volume and area to receive the detection light beam 101 from the emitting area. For example, but not limited to, the detection module requires a larger photosensitive area, or a larger volume of lens, etc. For example, the detection module needs to be provided with a lens with a larger volume, and the cross-sectional area of the lens needs to be not smaller than the area of the preset region P1; or the detection module needs to be provided with a relatively large-sized image sensor, and the area of the photosensitive region of the image sensor receiving the detection light beam 101 needs to be not smaller than the area of the preset region P5. So, in order to set up this detection module, even need crowd the space that occupies other parts originally, these all can influence whole volume, cost and the equipment of optical detection device 1, can not be applicable to the demand of setting up at the inside electronic product such as cell-phone.

Furthermore, according to the optical principle of total reflection, the horizontal distance between the exit area of the totally reflected detection beam 101 on the lower surface of the light guide unit and the light source 16 is greater than the horizontal distance between the preset area P1 and the light source 16. Moreover, the exit directions of the detection beams 101 exiting from the exit area follow the reflection and refraction principles, so that the detection modules receiving these detection beams 101 need to be arranged on the corresponding exit light paths to ensure the receiving and imaging effects. Therefore, the horizontal distance between the detection module and the light source 16 is greater than the horizontal distance between the predetermined area P1 and the light source 16. The detection module needs to be located at a side of the predetermined area P5 away from the light source 56, and the detection light beam 101 needs to be transmitted through a further path inside the light guiding unit for exiting, and needs to be transmitted outside the predetermined area P1 of the light guiding unit. In this case, if the light guide unit between the preset region P1 and the emission region is broken or broken, the detection light beam 101 cannot be emitted from the emission region on the lower surface of the light guide unit smoothly by total reflection. In other words, when the area outside the preset area P1 of the light guide unit is damaged, the receiving and imaging of the detection light beam are affected, and the user experience is reduced.

FIG. 7 is a partial cross-sectional view of an embodiment of the present invention. The optical inspection device 3 includes a protection layer 300, a display module 31, a light source 36 and an inspection module 39. The protective layer 300 and the display module 31 together form a display device. The display module 31 is located below the protection layer 300, and the display module 31 is configured to transmit a visible light beam through the protection layer 300 to realize image display. The light source 36 is located below the protective layer 300, the light source 36 is configured to emit a detection light beam 301, and the detection light beam 301 includes or is a non-collimated light beam. The detection light beam 301 is incident into the protective layer 300 from the lower surface of the protective layer 300, and the area where the detection light beam 301 reaches the upper surface of the protective layer 300 for the first time after transmission is a preset area P3. The preset area P3 is a directly irradiated area of the detection beam 301 on the upper surface of the protection layer 300. The detection module 39 has a view field region V3 on the upper surface of the protection layer 300, and the view field region V3 is a portion of the upper surface of the protection layer 300 located within the maximum range where the detection module 39 can receive the detection beam 301. At the time of fingerprint detection, the field of view region V3 is a region touched by a user's finger. The detection module 39 is located under the protection layer 300 or at least a portion of the detection module 39 is located under the display module 31. Of course, in other or modified embodiments, for example, but not limited to, during fingerprint detection, a light source may emit visible light at a position where the upper surface of the protection layer 300 faces the field of view region V3, so as to prompt a user to touch a finger at the position, and on the premise that fingerprint imaging is satisfied, an area of the upper surface of the protection layer 300 for the user to touch may partially overlap with the field of view region V3, or the touched area includes the field of view region V3, and the like, which is not limited by the present invention. It will be understood by those skilled in the art that the field of view region V3 or at least a portion thereof is a region touched by a finger, and is within the scope of the present invention.

In this embodiment, the protection layer 300 is a light guiding unit of the optical detection apparatus 3, and includes an upper surface 311 and a lower surface 312 opposite to each other. The protective layer 300 has a non-transparent region 310 and a transparent region 320 connected. The non-transparent area 310 is located around or at the edge of the transparent area 320. The transparent region 320 is used for transmitting a visible light beam. The non-transparent region 310 is used to block visible light. The visible light beam emitted by the display module 31 exits to the outside of the optical detection device 3 through the transparent area 320, so as to realize image display. The non-transparent area 310 is used for blocking the visible light beam emitted by the display module 31 and the visible light beam in the ambient light, so that the user cannot see the elements inside the optical detection device 3 in the non-transparent area 310.

Generally, an area of the display module 31 displaying an image is defined as a display area (not shown), and an area around the display area where the image cannot be displayed is defined as a non-display area (not shown). The transparent area 320 is directly opposite to the display area, and the vertical projection of the transparent area 320 in the display area is located in the display area or completely coincides with the display area. The non-transparent area 310 covers the non-display area and extends beyond the non-display area in a direction away from the display area. That is, the area of the non-transparent region 310 is larger than the area of the non-display region. When the user uses the optical detection device 3, the display area that the user can actually see on the front side of the optical detection device 3 is the same size as the transparent area 320.

Optionally, in some embodiments, the field of view region V3 is located directly above a local region of the display area. Further optionally, the detection module 39 includes an image sensor and an ultramicro-range lens located above the image sensor, wherein the ultramicro-range lens is configured to converge the detection light beam 301 onto the image sensor, the image sensor is configured to convert the detection light beam 301 into a corresponding electrical signal, a perpendicular projection of the ultramicro-range lens and the image sensor on the upper surface 311 is located within the field of view region V3, and an area of the perpendicular projection is smaller than an area of the field of view region V3

The non-transparent region 310 includes an upper surface (not shown) and a lower surface (not shown) disposed opposite to each other. The transparent region 320 includes an upper surface (not labeled) and a lower surface (not labeled) disposed opposite to each other. The upper surface 311 of the protective layer 300 includes the upper surface of the non-transparent region 310 and the upper surface of the transparent region 320. The lower surface 312 of the protective layer 300 includes the lower surface of the non-transparent region 310 and the lower surface of the transparent region 320.

The non-transparent region 310 is used for transmitting the detection beam 301 and blocking a visible beam. In the embodiment of the present application, the transmittance of the non-transparent region 310 to the detection light beam 301 is greater than a preset value. The preset value is 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90%. The intensity of the detection beam 301 after penetrating the protective layer 300 is greater when the non-transparent area 310 has a greater transmittance for the detection beam 301.

In addition, the non-transparent region 310 blocks the visible light beam by: the transmittance of the non-transparent region 310 for visible light beams is less than 10%, 5%, or 1%, even if the transmittance of the non-transparent region 310 for visible light beams is 0. The less the non-transparent region 310 transmits the visible light beam, the more the non-transparent region 310 blocks the visible light beam. Of course, alternatively, the transmittance of the non-transparent region 310 for visible light beams is not limited to less than 10%, as long as the internal elements are not visible from the outside of the protective layer 300 through the non-transparent region 310.

The non-transparent region 310 effects the blocking of the visible light beam, for example, but not limited to, by absorbing and/or reflecting the visible light beam.

The display module 31 is located below the transparent area 320. The light source 36 is located below the non-transparent region 310. The detection module 39 is located below the display module 31.

At least a portion of the light source 36 is proximate to the lower surface of the non-transparent region 310. The lower surface of the non-transparent region 310 has a light incident region 313, and the detection beam 301 enters the protective layer 300 from the light incident region 313. At least a portion of the detection beam 301 entering the protective layer 300 is able to directly irradiate and cover the preset area P3.

In this embodiment, the preset region P3 and the view field region V3 of the detection module 39 on the upper surface of the protection layer 300 have an overlapping region Q3. Optionally, in some embodiments, the preset region P3 is the field of view region V3. Optionally, in some embodiments, there is at least partial overlap between the preset region P3 and the field of view region V3, a portion of the preset region P3 overlapping the field of view region is defined as an overlapping region, and a portion of the preset region V3 other than the overlapping region is defined as a non-overlapping region. Further alternatively, the overlapping region may be the field of view region V3, when the field of view region V3 is a portion of the preset region P3.

In this embodiment, the detection light beam 301 enters the protective layer 300 from the light incident region 313 and is irradiated onto the predetermined region P3. Wherein: the detection light beam 301 irradiated to the overlap region Q3 satisfies the condition of total reflection transmission and can be diffusely reflected at the ridge 1100 (when the finger touches the field-of-view region V3); at least a part of the detection beam 301 irradiated to the non-overlapping region satisfies the condition of total reflection transmission, or the detection beam 301 irradiated to the non-overlapping region does not satisfy the condition of total reflection transmission. When at least part of the detection beams 301 irradiated to the non-overlapping region meets the condition of total reflection transmission, at least part of the detection beams 301 irradiated to the non-overlapping region and meeting the condition of total reflection transmission can reach the view field region V3 after multiple total reflections, and can be diffusely reflected at the ridge 1100 (when a finger touches the view field region V3), so that the protection layer 300 can be transmitted out and received by the detection module 39 located below the protection layer 300.

In this embodiment, the preset region P3 and/or the field of view region V3 are located on the upper surface of the transparent region 320. Optionally, in other or modified embodiments, at least a part of the preset region P3 and/or the field of view region V3 is located on the upper surface of the transparent region 320. Optionally, in other or modified embodiments, at least part of the preset region P3 and/or the field-of-view region V3 is located on the upper surface of the non-transparent region 310.

In this embodiment, the preset region P3 and the field of view region V3 are partial regions of the upper surface of the protective layer 300. For example, but not limiting of, the viewing area V3 is an area of the top surface of the protective layer 300 adjacent to 5 mm by 5 mm in the middle of the bottom thereof. There is at least a partial overlap of the preset region P3 and the field of view region V3. Part or all of the detection light beam 301 directly irradiated to the preset area P3 satisfies the condition of total reflection transmission in the protective layer 300, that is, the condition of total reflection in the light guiding unit of the optical detection device 3.

The conditions of the total reflection transmission include: the detection beam 301 is totally reflected at the upper surface 311 where it is not in contact with the ridges of the fingerprint, and totally reflected at the lower surface 312.

The detection light beam 301 is diffusely reflected at the contact position of the upper surface 311 and the ridge of the fingerprint, and the detection light beam 301 after diffuse reflection is irradiated towards all directions.

Alternatively, in some embodiments, all of the detection light beams 301 entering the protection layer 300 from the light incident region 313 can be transmitted by total reflection in the protection layer 300, that is, the detection light beams 310 irradiated to the preset region P3 satisfy the condition of total reflection transmission.

Alternatively, in some embodiments, at least a part of the detection light beam 301 entering the protection layer 300 from the light incident region 313 can be transmitted by total reflection in the protection layer 300, that is, a part or all of the detection light beam 301 irradiated to the preset region P3 satisfies the condition of total reflection transmission. Wherein all of the detection beams 301 directly irradiated to the overlapping area of the field of view area V3 and the preset area P3 satisfy the condition of total reflection transmission. The overlapping region may be a partial region of the field of view region V3, or the overlapping region which is the field of view region V3.

Alternatively, in some embodiments, a portion of the detection beam 301 entering the protective layer 300 directly irradiates an overlapping region of the field of view region V3 and the preset region P3, and a portion irradiates a non-overlapping region where the preset region P3 and the field of view region V3 do not overlap. At least part of the detection light beams 301 irradiated to the non-overlapping region meets the condition of total reflection transmission in the protective layer 300, and the part of the detection light beams 301 can be incident on the field of view region V3 after being totally reflected in the protective layer 300, and then can be diffusely reflected at the contact position of the field of view region V3 and the ridge 1100, and then can be received by the detection module 39 after penetrating out of the lower surface of the protective layer 300.

Optionally, in other embodiments, a local area of the preset area P3 and the field of view area V3 overlap and form an overlapping area. The overlapping region may be a local region of the field of view region V3, or the overlapping region may be the field of view region V3. A region where the preset region P3 does not overlap with the field of view region V3 is defined as a non-overlapping region. The non-overlapping region has a portion closer to the light source 36 than the field of view region V3. It is understood, for example and without limitation, that the non-overlapping region has a portion closer to the light source 36 than the field of view region V3 and the light source are spaced no further than the field of view region V3 and the light source 36. The area proportion of the non-overlapping region to the preset region P3, which is closer to the light source 36 than the field of view region V3, satisfies: not less than 30% and less than 100%. The area ratio of the corresponding overlapping region area to the field-of-view region V3 satisfies: not less than 30% and less than or equal to 100%. At this time, when the area ratio of the non-overlapping region to the preset region P3 is increased compared to the area ratio of the region of the portion of the field of view region V3 closer to the light source 36, more of the detection light beam 301 irradiated to the portion of the non-overlapping region closer to the light source 36 than the field of view region V3 is transmitted to the field of view region V3 by total reflection. Fig. 8 is a schematic perspective view of a part of the optical detection apparatus 3. The light entrance region 313 has a point a, the overlap region Q3 has a point b, and a straight line ab is a straight line having the shortest distance between the light entrance region 313 and the overlap region Q3. An included angle a1 between the line ab and the normal of the upper surface 311 is not less than a preset threshold. For example, but not limited to, the preset threshold is a critical angle of total reflection of the detection beam 301 when the overlapping region Q3 contacts with air.

Optionally, in some embodiments, the refractive index of the protection layer 300 is n1, the refractive index of air is n0, and the predetermined threshold is arcsin (n0/n 1). At this time, the normal angle between the detection light beam 301 projected to the overlap region Q3 and the overlap region Q3 is greater than or equal to a 1. When the upper and lower surfaces of the transparent region 320 of the protective layer 300 are in contact with air, the detection beam 301 can be transmitted by total reflection within the transparent region 320 of the protective layer 300.

When the user's finger touches the field of view region V3, part of the detection light beam 301 is diffusely reflected at the ridge 1100 of the finger fingerprint, and the part of the detection light beam 301 no longer transmits by total reflection, and at least part of the detection light beam 301 that is diffusely reflected can exit through the lower surface 312 of the transparent region 320 and reach the detection module 39.

It is understood that the overlap region Q3 exists between the preset region P3 and the field-of-view region V3 in the present embodiment, so that the detection light beam 301 directly illuminating the overlap region Q3 from the light incident region 313 also satisfies the condition of total reflection transmission within the light guiding unit, and total reflection occurs where the overlap region 13 contacts the ridge 1100 of the fingerprint 1000. And the detection light beam 301 irradiated onto the non-overlapping area where the preset area P3 does not overlap with the field of view area V3 may be refracted, reflected, and totally reflected at the non-overlapping area. The present embodiment assumes that at least part of the detection light beam 301 irradiated to the non-overlapping region of the preset region P3 can be transmitted by total reflection within the light guiding unit. Then, for a partial region of the field of view region V3 other than the overlapping region Q3, at least a portion of the detection beam 301 directly illuminating the non-overlapping region where the preset region P3 does not overlap the field of view region V3 can be illuminated to the field of view region V3 by multiple total reflections, for example, but not limited to, can be illuminated to the overlapping region Q3 by multiple total reflections and/or a portion of the field of view region V3 that does not overlap the preset region P3. In addition, at least a part of the detection beam 301 directly irradiated to the overlapping region Q3 may be irradiated to a part of the field-of-view region V3 that does not overlap the preset region P3 after being totally reflected for a plurality of times. The detection light beam 301 irradiated to the field of view region V3 after multiple total reflections can be diffusely reflected at the contact position of the field of view region V3 and the ridge 1100, and at least part of the diffusely reflected detection light beam 301 may be received by the detection module 39 and used for imaging the fingerprint 1000.

Illustratively, the protective layer 300 is, for example and without limitation, transparent glass having a refractive index of n1 ═ 1.5. The air refractive index n0 is 1.0. The preset threshold is 42 degrees. Optionally, the predetermined threshold is 42 degrees ± 3 degrees in some embodiments, taking into account material and assembly errors. Of course, in other or modified embodiments, when the material is different, the refractive index of different materials is different, and the predetermined threshold value may also be changed accordingly, all of which belong to the protection scope of the present invention. The embodiment of the present invention is not limited thereto.

It can be understood that, since the shortest right angle between the light incident region 313 and the field of view region V3 and the angle between the normal of the field of view region V3 are not less than the preset threshold, the detection light beam 301 directly irradiated to the field of view region V3 satisfies the condition of total reflection transmission.

Optionally, in some embodiments, the preset region P3 is a direct irradiation region of the detection beam 301 on the upper surface of the light guide unit, and when the preset region P3 and the field of view region V3 have an overlapping region, the overlapping region is a region of the field of view region V3 to which the detection beam 301 is directly irradiated. An included angle between a shortest straight line between the light incident region 313 and the overlapping region and a normal of the upper surface of the light guide unit is not less than a preset threshold, and the preset threshold satisfies a condition that the detection light beam 301 is transmitted in a total reflection manner inside the light guide unit.

In this embodiment, the refractive index of the protection layer 300 is greater than that of air. Alternatively, in some embodiments, the protection layer 300 may be a protection layer made of a transparent material, and the upper surface 311 of the protection layer 300 is a surface that a user directly touches with a finger when using the optical detection apparatus 1. The upper surface 311 of the protective layer 300 includes an upper surface of a transparent region and an upper surface of a non-transparent region. The non-transparent region 310 and the transparent region 320 are integrally formed. Optionally, in other or modified embodiments, at least a portion of the non-transparent region 310 and the transparent region 320 are integrally formed, or the non-transparent region 310 and the transparent region 320 are assembled. Alternatively, in some embodiments, the protective layer 300 is, for example and without limitation, a protective layer comprising a material such as glass or sapphire.

At the time of fingerprint detection, including but not limited to, unlocking the optical detection device 1 or making a payment through the optical detection device 1, the user's finger touches the field of view region V3. The area on the field-of-view area V3 that is in contact with the ridges 1100 of the fingerprint 1000 is defined as a ridge area, and the area opposite to the valleys 1200 of the fingerprint 1000 by spacers is defined as a valley area. The detection light beam 301 directly or indirectly irradiated to the ridge region after total reflection is subjected to diffuse reflection, and at least part of the diffusely reflected detection light beam 301 passes through the lower surface 322 of the transparent region 320 and the display module 31 to reach the detection module 39. The detection module 39 receives the detection beam 301 and converts it into a corresponding electrical signal, which may be used, for example and without limitation, to form an image of the fingerprint 1000 or to represent a feature of the fingerprint 1000.

The detection beam 301 directly or indirectly illuminating the valley region after total reflection is totally reflected. Since the valley region is opposite to the valley 1200, the example of the spacer is air in this embodiment, and it can be understood by those skilled in the art that the spacer can be water, liquid, sweat, or other objects.

Optionally, in other or modified embodiments, when detecting a fingerprint, a partial area of the preset area P3 does not contact the ridge 1100 and is not opposite to the valley 1200, and these areas are areas not covered by the fingerprint, and an area on the preset area P3 not covered by the fingerprint 1000 is defined as an empty area. The detection beam 301 directly impinging on the empty area is totally reflected.

Optionally, the optical detection device 3 further includes a bracket, and the light source 36 may be fixedly connected or detachably connected to the bracket by glue, double-sided tape, adhesive, bolt, bracket, fastener, slot, welding, or the like. Further alternatively, the bracket may be any component for fixedly connecting with the protective layer 300 and/or the display module 31, such as, but not limited to, a middle frame fixedly connected with the protective layer 300, the display module 31 may be accommodated in the middle frame, and the light source 36 is connected to the inner side wall or the bottom of the middle frame.

Optionally, the detection module 39 may be fixedly connected or detachably connected to a bracket by glue, double-sided tape, adhesive, bolt, bracket, fastener, slot, welding, or the like.

In this embodiment, the display module 31 may be, for example, but not limited to, a liquid crystal display module, an electronic paper display module, a micro-display projector module, and the like. The display module 31 may include a display unit (not shown) under the protective layer 300 and a backlight unit (not shown) under the display unit. The backlight unit is used for providing backlight beams of visible light to the display unit, and the display unit is used for displaying images under the illumination of the backlight beams. The display unit and the backlight unit can transmit the detection light beam which is emitted from the lower surface of the light guide unit after being diffusely reflected at the finger ridge of the preset area.

Optionally, the detection module 39 is at least partially located below the backlight unit; or the detection module is positioned in the display unit, or the detection module is positioned in the backlight unit, or the detection unit is positioned between the display unit and the backlight unit

Alternatively, in other or modified embodiments, the display module 31 includes two opposite substrates and a display layer located between the substrates, and the display layer may be an Organic Light Emitting Diode (OLED) layer or a liquid crystal layer. It should be noted that the present invention is not limited in sequence, and the display module 31 may be other suitable display modules, display modules or displays. Alternatively, in some embodiments, the display module 31 may be a self-luminous display device, and the display module 31 and the protective layer 300 together form a self-luminous display device.

Referring to fig. 9, in the present embodiment, the light source 36 includes a light emitting unit 361 and a light converter 362. The light emitting unit 361 emits a non-collimated detection beam 301. The optical converter 362 is configured to convert an angle at which the detection light beam 301 emitted by the light emitting unit 361 enters the protection layer 300, so that at least a portion of the detection light beam 301 entering the protection layer 300 can directly irradiate the preset region P3 and meet a condition of total reflection transmission in the protection layer 300, that is, a condition of total reflection in a light guiding unit of the optical detection device 3. For example, but not limited to, the angle of the detection beam 301 relative to the normal of the preset area P3 when entering the protection layer 300 through the light converter 362 satisfies a preset condition, so that the detection beam 301 can be transmitted by total reflection inside the protection layer 300. The light converter 362 is closely attached to the lower surface of the non-display region 310. The light emitting surface of the light converter 362 for emitting the detection beam 301 covers at least the light incident region 313. In this embodiment or other modifications, the optical converter 362 may include one or more of an optical film, a grating, a diaphragm, an optical microstructure, a diffractive optical element, a lens, a prism structure, a spherical structure, a semi-cylindrical structure, or other optical structures, or a combination thereof.

Alternatively, in some embodiments, the light converter 362 may be omitted or integrated in the protection layer 300, and the light emitting unit 361 directly emits the detection beam 301 into the protection layer 300 or the light guiding unit.

Alternatively, in some embodiments, an incident angle of the detection beam 301 with respect to the preset area P3 when entering the protective layer 300 is not less than a critical angle of total reflection when the upper surface of the protective layer 300 is in contact with air. For example, but not limiting of, the incident angle magnitude is not less than 42 degrees.

Optionally, in some embodiments, the light converter 362 is disposed between the light emitting surface of the light emitting unit 361 and the lower surface of the protection layer 300, or the light converter 362 and the protection layer 300 are integrally formed, and the light incident region 313 is a partial surface of the light converter 362.

Optionally, in some embodiments, the light guide unit may include a first surface and a second surface, the light converter 362 is disposed between the light emitting surface of the light emitting unit 361 and the second surface of the light guide unit, and the light incident region 313 is located on the second surface. The detection light beam 301 enters the light guide unit from the second surface of the light guide unit and can be directly irradiated onto the first surface; alternatively, the light converter 362 and the light guide unit are integrally formed, and the light incident region 313 is a partial surface of the light converter 362.

Alternatively, in some embodiments, the number of the preset regions P3 may be multiple, for example, but not limited to, different preset regions P3 are respectively provided near the top and the bottom of the protection layer 300.

Alternatively, in some embodiments, the number of the light incident regions 313 may be multiple, for example, but not limited to, different light incident regions 313 are respectively arranged near the top and the bottom of the protection layer 300.

Alternatively, in some embodiments, the number of the light sources 36 may be multiple, for example, but not limited to, the light sources 36 may be disposed under the non-transparent region 310 of the protection layer 300 at different positions corresponding to the non-transparent region 310.

Optionally, in some embodiments, the refractive index of the light converter 362 is greater than the refractive index of the protective layer 300. It can be understood that when the detection light beam 301 enters the protection layer 300 from the light incident region 313, refraction occurs at the interface of the light converter 362 and the light incident region 313, and the refraction angle is larger than the incident angle.

Optionally, in some embodiments, the light source 36 may further include a circuit board, and the light emitting unit 361 is connected to the circuit board, and the circuit board is configured to provide the light emitting unit 361 with an electrical signal required for emitting the detection light beam 301, where the electrical signal is, for example, but not limited to, a current, a voltage, and the like.

Optionally, in some embodiments, the light source 36 may further include a circuit board, which is a flexible circuit board, and the circuit board is electrically connected to the light emitting unit 361, and the circuit board may be fixedly connected or detachably connected to a side portion and/or a bottom portion of a middle frame by glue, double-sided tape, adhesive, bolts, brackets, snaps, slots, or welding.

Alternatively, in some embodiments, the detection module 39 may be fixedly connected or detachably connected to the side and/or bottom of a middle frame by glue, double-sided tape, adhesive, bolts, brackets, snaps, slots, welds, or the like.

Optionally, in some embodiments, the number of the light emitting units 361 may be one or more, such as but not limited to: 1, 2, 3, 4.

Optionally, referring to fig. 10, in a modified embodiment of the optical detection apparatus 3, the light converter 362 is a prism, a light-emitting surface of the light-emitting unit 361 is tightly attached to a light-entering surface of the prism, the light-emitting surface of the prism is tightly attached to the lower surface 312 of the non-transparent area 310, and the light-emitting surface of the prism is opposite to the light-entering area 313. Further, the prism is a triangular prism. Further, an included angle between the light incident surface of the prism and the lower surface 312 is within a range of 60 ± 5 degrees. In other or modified embodiments, the prism may be a pentaprism, or other prisms.

Optionally, referring to fig. 11, in a modified embodiment of the optical detection apparatus 3, the light emitting unit 361 is disposed under the light converter 362 opposite to the light converter 362. The light converter 362 is disposed proximate the lower surface 312 of the non-transparent region 310. The light converter 362 is an optical film having a saw-toothed microstructure, and the saw-toothed microstructure faces the light-emitting surface of the light-emitting unit 361. The tooth-shaped microstructure can change the angle of the detection light beam 301 emitted by the light emitting unit 361 and then emit the detection light beam into the protective layer 300. Further optionally, the lower surface 312 has recesses, and the saw-tooth like microstructures are located or at least partially located within the recesses.

Optionally, the light emitting surface of the light emitting unit 361 for emitting the detection light beam 301 and the light converter 362 are spaced apart by a distance such as, but not limited to: 1 mm, 2 mm, 3 mm, 4 mm, 5 mm.

Alternatively, in some embodiments, the detection light beam 301 emitted from the light emitting unit 361 is a non-collimated light beam, which may have a light emitting angle range of 10 degrees to 140 degrees. For example, but not limited to, the detection light beam 301 emitted by the light emitting unit 361 has an emission angle of 50 degrees to 140 degrees. When the light emitting angle of the light emitting unit 361 is large, for example, larger than 50 degrees, the light converter 362 can convert the detection light beam 301 emitted by the light emitting unit 361 into an uncollimated light beam with a larger divergence angle, where the divergence angle is understood as the largest included angle between two light rays in the detection light beam 301 converted by the light converter 362.

Optionally, the shape of the preset region P3 and/or the field of view region V3 may be square, circular, oval, and the like, which is not limited in the embodiments of the present invention. Optionally, the field of view region V3 is circular with a radius in the range of 2 to 5 mm or 3 to 4 mm or 3 to 5 mm.

Optionally, the light emitting unit 361 is, for example, but not limited to, one or more of an LED (light emitting diode), an LD (laser diode), a VCSEL (vertical cavity surface emitting laser), a Mini-LED, a Micro-LED, an OLED (organic light emitting diode), and a QLED (quantum dot light emitting diode), or a light emitting array including one or more of an LED, an LD, a VCSEL, a Mini-LED, a Micro-LED, an OLED, and a QLED.

Optionally, in some embodiments, the protection layer 300 includes a transparent substrate and a light shielding film. The transparent substrate includes a portion located in the non-transparent region 310 and a portion located in the transparent region 320. The light shielding film is located under the transparent substrate opposite to the non-display area 310, and can be used for transmitting a detection light beam 301 and intercepting visible light.

The light converter 362 may be formed on the lower surface of the light shielding film, or the light converter 362 may be integrally formed with the light shielding film. Further alternatively, the light shielding film may be omitted. At this time, the non-transparent region 110 of the protective layer 300 (i.e., the light guide unit) may be made of a visible light opaque material. Further alternatively, the light shielding film may be integrated on the lower surface, the upper surface, and the inside of the substrate. Further optionally, the light shielding film has a transmittance of greater than 50%, or 60%, or 70% for the detection light beam 301. The light-shielding film has a transmittance of less than 10%, or 5%, or 1% for visible light. Further optionally, the light-shielding film is, for example, but not limited to, an infrared ink. In other or modified embodiments, the light shielding film may have different structures and functions according to design requirements, which is not limited in the embodiments of the present invention.

The optical detection device 3 uses the non-collimated detection beam 301, transmits the detection beam 301 passing through the non-overlapping area of the preset area P3 to the view field area V3 through total reflection by directly projecting the detection beam 301 to the overlapping area of the preset area P3 and the view field area V3, and receives the detection beam 301 diffused and reflected at the contact position of the view field area V3 and the ridge 1100 under the display module 31, so that the optical image of the fingerprint 1000 of the view field area V3 can be captured, and the fingerprint detection under the screen can be realized.

Referring to fig. 12, in an embodiment of the invention, the optical detection apparatus 4 includes a light guide unit 400, a display module 41, a light source 46 and a detection module 49. The display module 41 is located below the light guide unit 400, and the display module 41 is configured to emit a visible light beam through the light guide unit 400 to display an image. The light source 46 is located below the light guide unit 400, and the light source 46 is used for emitting a detection light beam 401. The light guide unit 400 includes an upper surface 411 and a lower surface 412 opposite to each other. The upper surface 411 is an outer surface of the optical detection device 4. The optical detection device 4 further comprises a protective layer 42 and an optical cement 43, wherein the upper surface of the optical cement 43 is closely attached to the lower surface of the protective layer 42. In this embodiment, the light guide unit 400 includes the protective layer 42 and the optical adhesive 43. The upper surface of the protective layer 42 is the upper surface 411.

The detection beam 401 comprises a non-collimated beam. The detection light beam 401 is incident from the lower surface 412 of the light guide unit 400 and can be directly irradiated to at least one predetermined area P4 on the upper surface 411 of the light guide unit 400. The preset area P4 is the direct irradiation area of the detection beam 401 on the upper surface 411. The upper surface 411 further has a field of view region V4, and the field of view region V4 or at least a partial region thereof is a region touched by a finger of a user when fingerprint detection is performed. The detection module 49 is located below the light guide unit 400. In the present embodiment, there is an at least partial overlapping region between the preset region P4 and the field-of-view region V4. Optionally, in some embodiments, the preset region P4 and the field of view region V4 do not overlap.

The protective layer 42 has a transparent region 420 and a non-transparent region 410. The non-transparent region 410 is located around or at an edge of the transparent region 420. The transparent region 420 is used to transmit a visible light beam. The non-transparent region 410 is for blocking visible light. The visible light beam emitted from the display module 41 exits to the outside of the optical detection device 4 through the optical adhesive 43 and the protective layer 42 located in the transparent area 420, so as to realize image display. The protection layer 42 located in the non-transparent area 410 is used for blocking the visible light beam emitted by the display module 41 and the visible light beam in the ambient light, so that the internal elements of the optical detection device 4 are not visible to the user in the non-transparent area 410.

The non-transparent region 410 includes upper and lower oppositely disposed surfaces, and the transparent region 420 includes upper and lower oppositely disposed surfaces. In this embodiment, the upper surface 411 of the light guide unit 400 is the upper surface of the protection layer 42, that is, the upper surface of the non-transparent area 410 and the upper surface of the transparent area 420. Optionally, in some embodiments, the upper surface 411 of the light guide unit 400 is an outer surface of an outermost layer of the optical detection device 4, and a user's finger may directly touch the upper surface 411 of the light guide unit 400. The lower surface 412 of the light guide unit 400 includes at least a portion of the lower surface of the optical glue 43.

The non-transparent region 410 of the protective layer 42 extends from the upper surface to the lower surface of the protective layer 42. The protective layer 42 includes a transparent substrate 421 and a light shielding film 422. The transparent substrate 421 includes an upper surface and a lower surface opposite to each other. The light shielding film 422 is disposed on an edge region of the lower surface of the transparent substrate 421 within the non-transparent region 410. The lower surface of the transparent substrate 421 faces the display module 41, and the upper surface of the transparent substrate 421 faces away from the display module 41. The non-transparent region 410 includes the light shielding film 422 and a portion of the transparent substrate 421 facing the light shielding film 422. The refractive index of the transparent substrate 421 is greater than that of air.

In the embodiment of the present application, the transparent substrate 421 has a single-layer structure, and the upper surface of the transparent substrate is the upper surface of the protection layer 42, that is, the upper surface 411 of the light guide unit 400. In this embodiment, the lower surface of the transparent substrate 421 is a part of the lower surface of the protection layer 42. The transparent region 420 is disposed side by side with the non-transparent region 410. The transparent substrate 421 includes a portion located in the transparent region 420 and a portion located in the non-transparent region 410.

However, the transparent substrate 421 may alternatively be a multi-layer structure, and the multi-layer structure is stacked on each other and is not limited to have the same size. In addition, the multilayer structures are closely attached or closely adjacent to each other. For example, the light shielding film 422 is located between two adjacent layers of the transparent substrate 421, and the two adjacent layers are disposed closely or at intervals. However, the multi-layer structures may be located on the same side of the light-shielding film 422, and in this case, the multi-layer structures are disposed close to each other.

The transparent substrate 421 includes a soft structure and/or a hard structure. The transparent substrate 421 is made of one or more materials such as resin, glass, and sapphire.

The light shielding film 422 has a higher transmittance for the detection beam 401 than for the visible beam. The light-shielding film 422 has a single-layer structure or a multi-layer structure. When the light shielding film 422 is a multi-layer structure, the transmittance of the light shielding film 422 to the detection light beam is the product of the transmittances of the respective layers of the structure to the detection light beam. When the light shielding film 422 is a multi-layer structure, the multi-layer structure is disposed closely, closely or at intervals, for example.

The light shielding film 422 is, for example, an infrared cover ink. However, the light shielding film 422 may also be other suitable structures, such as a multilayer film structure, which can transmit the detection beam and shield visible light. Preferably, the light shielding film 422 covers at least a light incident region of the detection light beam on the lower surface of the transparent substrate 421. The optical glue 43 is located below the protective layer 42. The optical adhesive 43 is used for connecting the display module 41 and the protective layer 42. The optical glue 43 covers at least part of the protective layer 42 in the transparent area 420. Optionally, in some embodiments, the optical glue 43 covers at least a portion of the protective layer 42 in the non-transparent region 410.

The display module 41 is located below the optical adhesive 43. The light source 46 is located below the corresponding non-transparent region 410 of the protective layer 42. The detection module 49 is located below the display module 41. Alternatively, in other or modified embodiments, the detection module 49 may be located inside the display module 41.

At least a portion of the light source 46 is closely attached to the protective layer 42 and located on the lower surface of the non-transparent region 410, i.e. the lower surface of the light shielding film 422 in this embodiment. The lower surface of the non-transparent region 410 has a light incident region 413, and the detection beam 401 enters the light guide unit 400 from the light incident region 413. The detection beam 401 entering the light guiding unit 400 directly irradiates and covers the preset area P4.

In this embodiment, the preset region P4 and the field of view region V4 of the detection module 49 on the upper surface of the light guide unit 400 have an overlapping region. Alternatively, in other or modified embodiments, for example and without limitation, the preset region P4 may be a portion of the field of view region V4, which may be located in the field of view region V4. Alternatively, in other or modified embodiments, for example and without limitation, the field-of-view region V4 may be a part of the preset region P4, which may be located in the preset region P4.

In this embodiment, the preset region P4 and the field of view region V4 are located on the upper surface of the protective layer 42. Optionally, in other or modified embodiments, at least a part of the preset region P4 and/or the field-of-view region V4 is located on the upper surface of the protection layer 42.

The detection light beam 401 irradiated to the overlapping area of the preset area P4 and the field of view area V4 satisfies the condition of total reflection transmission within the light guiding unit 400. Alternatively, in another or modified embodiment, the detection light beam 401 entering the light guiding unit 400 from the light incident region 413 satisfies the condition of total reflection transmission in the light guiding unit 400, that is, the detection light beam 401 irradiated to the preset region P4 satisfies the condition of total reflection transmission in the light guiding unit 400. Optionally, in some embodiments, at least a portion of the detection light beam 401 irradiated to the non-overlapping region where the preset region P4 does not overlap with the field of view region V4 satisfies the condition of total reflection transmission in the light guide unit 400.

The conditions of the total reflection transmission include: the detection beam 401 is totally reflected at the upper surface 411 where it is not in contact with the ridges 1100 of the fingerprint 1000, and totally reflected at the lower surface 412.

The detection beam 401 is diffusely reflected at the contact position of the upper surface 411 and the ridge 1100 of the fingerprint 1000, and the detection beam 401 after diffuse reflection is irradiated towards all directions.

In this embodiment, the refractive indexes of the protective layer 42 and the optical adhesive 43 of the light guide unit 400 are substantially the same, and for convenience of description, the refractive index is referred to as the refractive index of the light guide unit 400. The light guide unit 400 has a refractive index greater than that of air. Optionally, in some embodiments, the refractive index of the protective layer 42 is greater than or equal to the refractive index of the optical glue 43. Alternatively, in some embodiments, the light guide unit 400 may be a protective layer made of a transparent material, and the upper surface 411 of the light guide unit 400 is a surface that a user directly touches with a finger when using the optical detection apparatus 1. The portion of the protection layer 42 located in the non-transparent region 410 and the portion of the protection layer 42 located in the transparent region 420 are integrally formed. The protective layer 42 and the optical glue 43 are disposed in close contact or lamination. The protective layer 42 is connected to the display module 41 through the optical adhesive 43.

Optionally, the optical cement 43 is made of a transparent material, and the refractive index of the optical cement 43 is smaller than or equal to the refractive index of the protective layer 42. Of course, the invention is not limited in this regard, and in some embodiments, the refractive index of the optical glue 43 or a portion thereof may be greater than the refractive index of the protective layer 42.

In the fingerprint detection, the ridges 1100 of the fingerprint 1000 contact the upper surface of the light guide unit 400, and the valleys 1200 of the fingerprint 1000 face the upper surface 411 of the light guide unit 400 through spacers. The detection beam 401 is diffusely reflected at the ridge 1100 and totally reflected opposite the valley 1200. The detection beam 401 diffusely reflected at the ridge 1100 reaches the detection module 49 through the protection layer 42 located in the transparent area 420, the optical glue 43, and the display module 41. The detection module 49 receives the detection beam 401 and converts it into an electrical signal, which can be used for image generation or detection of the fingerprint 1000.

The optical detection device 4 uses the non-collimated detection beam 401, transmits the detection beam 401 to the field of view area V4 through total reflection by directly projecting the detection beam 401 to the overlapping area of the preset area P4 and the field of view area V4 and the detection beam 401 passing through the non-overlapping area of the preset area P4, and receives the detection beam 401 diffused and reflected at the contact position of the field of view area V4 and the ridge 1100 under the display module 41, so that the optical image of the fingerprint 1000 of the field of view area V4 can be captured, and the fingerprint detection under the screen can be realized.

Referring to fig. 13, in an embodiment of the invention, the optical inspection apparatus 5 includes a protection layer 52, an optical adhesive 53, a light source 56, a display module 51, and an inspection module 59.

The display module 51 includes an array substrate 541, a liquid crystal layer 542, an alignment film 543, a common electrode 544, a color filter 545, a substrate 546, and a polarizing plate 547 stacked in sequence from bottom to top. In this embodiment, the display module 51 is, for example, but not limited to, a liquid crystal display module. The common electrode 544, the color filter 545, the substrate 546 and the polarizer 547 together form a color filter substrate of the display module 51.

Optionally, in some embodiments, the display module 51 further includes a backlight unit located below the array substrate 541. At this time, the array substrate 541, the liquid crystal layer 542, the alignment film 543, the common electrode 544, the color filter 545, the substrate 546, and the polarizing plate 547 may be collectively regarded as a display unit, and the backlight unit is located below the display unit. The protective layer 52, the display unit and the backlight unit together constitute a display device.

The protective layer 52 includes oppositely disposed upper and lower surfaces. The light source 56 is positioned below and spaced from the upper surface of the protective layer 52. The light source 56 is used to project a non-collimated detection beam 501 towards the upper surface. The detection beam 501 can be transmitted at least by total internal reflection in the protective layer 52. An area where the detection light beam 501 entering the inside of the protective layer 52 from the light source 56 is transmitted and first reaches the upper surface is defined as a preset area P5. The detection module 59 has a field of view region V5 on the upper surface. When no finger touches the preset area P5, there is a total reflection of the detection beam in the field of view area V5. When a finger touches the field of view region V5, the detection light beam 501 is diffusely reflected at the fingerprint ridge 1100 touching the field of view region V5, and the detection light beam 501 is totally reflected at the position where the field of view region V5 is opposite to the fingerprint valley 1200. At least part of the detection light beam 501 which is diffused and reflected passes through the protection layer 52 to be received by the detection module 59, and the detection module 59 converts the received detection light beam into a corresponding electric signal.

Optionally, in some embodiments, the light source 56 is located below the protective layer 52. The optical glue 53 is located below the protective layer 52. The display module 51 is located below the optical cement 53, and the detection module 59 is located below the display module 51. Alternatively, in other or modified embodiments, the detection module 59 may be located inside the display module 51.

In this embodiment, the protective layer 52, the optical adhesive 53, and the polarizing plate 547 together constitute a light guide unit (not numbered) of the optical detection apparatus 1. The light guide unit includes opposite upper and

lower surfaces

511 and 512.

The protective layer 52 has a non-transparent region 510 and a transparent region 520. The non-transparent region 510 includes an upper surface (not shown) and a lower surface (not shown) disposed opposite to each other. The transparent region 520 includes an upper surface (not labeled) and a lower surface (not labeled) disposed opposite to each other. The transparent region 520 can transmit visible light and invisible light, and the non-transparent region 510 can block visible light and transmit invisible light. In this embodiment, the upper surface 511 of the light guide unit includes the upper surface of the non-transparent region 510 and the upper surface of the transparent region 520. The lower surface 512 of the light guide unit includes at least a portion of the lower surface of the polarizing plate 547.

The upper surface of the optical adhesive 53 is disposed in close contact with the lower surface of the protective layer 52. The upper surface of the polarizing plate 517 is closely attached to the lower surface of the optical adhesive 53.

The light source 56 is located below the non-transparent region 510 of the protective layer 52. The display module 51 is located below the optical cement 53. The detection module 59 is located below the display module 51. Alternatively, in other or modified embodiments, the detection module 59 may be located inside the display module 51.

Optionally, in some embodiments, the detection module 59 may include an image sensor capable of receiving the detection light beam 501 and converting the detection light beam into an electrical signal, such as, but not limited to, image data of the fingerprint 1000. Further optionally, for example and without limitation, the detection module 59 may further include a lens and/or a collimator lens located above the image sensor, and the detection beam 501 passes through the lens and/or the collimator lens and then is imaged on the image sensor.

When the visual field region in the embodiment of this application is in just during the local area to the display area on the protective layer, because optical detection device 5 adopts diffuse reflection to carry out the fingerprint sensing, consequently, the size and the volume of the detection module 59 of this application can be less to can be applicable to under the screen fingerprint detection demand under the requirement condition that satisfies the frivolous requirements of electronic products such as cell-phone.

At least a part of the light source 56 is closely attached to the lower surface of the non-transparent region 510 of the protective layer 52, the lower surface of the non-transparent region 510 has a light incident region 513, and the detection light beam 501 enters the light guide unit of the optical detection device 5 from the light incident region 513. A directly irradiated region on the upper surface 511 of the light guiding unit in the detection light beam 501 entering the light guiding unit is defined as a preset region P5. In this embodiment, the preset area P5 is located on the upper surface of the transparent area 520. Optionally, in some embodiments, at least a portion of the preset area P5 is located on the upper surface of the transparent area 520.

The detection module 59 has a field of view region V5 on the upper surface 511 of the light guide unit. In this embodiment, the field region V5 is located on the upper surface of the transparent region 520. Optionally, in some embodiments, at least a portion of the field of view region V5 is located on the upper surface of the transparent region 520.

In the present embodiment, the preset region P5 and the field-of-view region V5 have an overlapping region. Alternatively, in other or modified embodiments, the preset region P5 may be a part of the field of view region V5, which may be located in the field of view region V5. In other or modified embodiments, the field of view region V5 may be a portion of the preset region P5, which may be located in the preset region P5. Optionally, in other or modified embodiments, the preset region P5 and the field of view region V5 do not overlap.

Optionally, in some embodiments, for example and without limitation, the preset region P5 is a part of the field of view region V5, and the area of the overlapping region of the area of the preset region V5 and the field of view region V5 is not less than 50%, 60%, 70%, 80%, or 90% of the area of the field of view region V5. Like this, when the finger touch is in the visual field region V5 top, there is sufficient detection light to carry out the diffuse reflection by the ridge of fingerprint and enter into detect module 59 to can guarantee fingerprint detection effect.

If insufficient detection light is directly incident on the field-of-view area V5, when the finger touches the preset area P5, the ridge of a part of the fingerprint diffusely reflects the detection light beam, and the diffusely reflected detection light beam is not transmitted to the remaining fingerprint ridge which is not in contact with the detection light beam, i.e., the ridge of the fingerprint adjacent to the detection light beam cuts off the detection light beam, and the ridge of the fingerprint far away from the detection light beam does not contact the detection light beam or less contact the detection light beam, so that the ridge of a part of the fingerprint does not contact the detection light beam, and the detection module 59 cannot obtain a complete fingerprint image according to the received detection light beam.

In addition, besides directly projecting the detection light beam 501 to the overlapping area, the light source 56 also projects the detection light beam 501 to an area adjacent to the light source 56 except the overlapping area, and at least part of the detection light beam 501 projected to the part of the area meets the condition of total reflection transmission in the light guide unit. When the part of the detection light beam 501 is transmitted to the field area V5 by total reflection and meets the ridge 1100 of the fingerprint, diffused reflection occurs and the detection light beam is emitted to the detection module 59, so that the detection accuracy of the fingerprint can be further improved, and a better fingerprint detection effect can be obtained.

Optionally, in some embodiments, the preset region P5 is a portion of the field-of-view region V5 or the field-of-view region V5 is a portion of the preset region P5, and a maximum distance between an edge of the preset region P5 and an edge of the field-of-view region V5 is not greater than 1 mm, 2 mm, or 3 mm.

Optionally, in some embodiments, part or all of the detection light beam 501 irradiated to the preset region P5 satisfies the condition of total reflection transmission in the light guide unit.

Alternatively, a part of the detection beam 501 entering the light guide unit from the light incident region 513 may be irradiated to a part outside the preset region P5 on the upper surface of the protective layer 52, and the part of the detection beam 501 may be reflected or totally reflected inside the light guide unit and may be irradiated to the view field region V5 after being reflected or totally reflected. Part of the detection light beam 501 which can be incident on the field of view region V5 after reflection or total reflection is diffusely reflected at the ridge 1100 of the fingerprint 1000, and can be emitted through the lower surface of the light guide unit and received by the detection module 59.

The conditions of the total reflection transmission include: the detection beam 501 is totally reflected at the upper surface 511 where it does not contact the ridge 1100 of the fingerprint, and totally reflected at the lower surface 512.

The detection light beam 501 is diffusely reflected at the contact position of the upper surface 511 and the ridge 1100 of the fingerprint, and the detection light beam 501 after diffuse reflection is irradiated towards all directions.

In this embodiment, the refractive indexes of the polarizing plate 547, the optical adhesive 53, and the protective layer 52 are substantially the same and larger than the refractive index of air. The light guide unit may be regarded as a uniform medium. Optionally, in some embodiments, the upper surface of the protection layer 52, i.e. the upper surface 511 of the light guiding unit, is also the outer surface of the optical detection device 5 that is directly touched by a finger when a user performs fingerprint detection.

The substrate 546 is made of a transparent material, such as, but not limited to, glass or plastic. The color filter 545 is used to filter the white visible light into red, green, blue, or other colored light. The color filter 545 is made of, for example, but not limited to, resin or other materials. The common electrode 544 is, for example, but not limited to, a transparent electrode, such as an ITO electrode. The alignment film 543 aligns liquid crystal molecules of the liquid crystal layer 542.

In this embodiment, the light guide unit includes the protective layer 52, an optical adhesive 53 under the protective layer, and a polarizing plate 547 under the optical adhesive.

Optionally, in other or modified embodiments, the light guide unit protection layer 52, the optical glue 53 located below the protection layer 52, the polarizing plate 547 located below the optical glue 53, and the substrate 546 located below the polarizing plate 547.

Optionally, in other or modified embodiments, the light guide unit includes a protective layer 52, an optical glue 53 located below the protective layer 52, a polarizing plate 547 located below the optical glue 53, a substrate 546 located below the polarizing plate 547, and a color filter 545.

Optionally, in other or modified embodiments, the light guiding unit includes a protective layer 52, an optical adhesive 53 located below the protective layer 52, a polarizing plate 547 located below the optical adhesive 53, a substrate 546 located below the polarizing plate 547, a color filter 545, and a common electrode 544.

Optionally, in other or modified embodiments, the light guide unit includes a protection layer 52, an optical glue 53 located below the protection layer 52, a polarizing plate 547 located below the optical glue 53, a substrate 546 located below the polarizing plate 547, a color filter 545, a common electrode 544, and an alignment film 543.

Optionally, in other or modified embodiments, the light guide unit includes a protection layer 52, an optical adhesive 53 located below the protection layer 52, a polarizing plate 547 located below the optical adhesive 53, a substrate 546 located below the polarizing plate 547, a color filter 545, a common electrode 544, an alignment film 543, and a liquid crystal layer 542.

Optionally, in other or modified embodiments, the light guide unit includes a protection layer 52, an optical adhesive 53 located below the protection layer 52, a polarizing plate 547 located below the optical adhesive 53, a substrate 546 located below the polarizing plate 547, a color filter 545, a common electrode 544, an alignment film 543, a liquid crystal layer 542, and an array substrate 541.

Alternatively, in other or modified embodiments, the display module 51 may have other different structures, for example, but not limited to, the array substrate 541, the liquid crystal layer 542, the alignment film 543, the common electrode 544, the color filter 545, the substrate 546, and the polarizer 547 in this embodiment may be partially omitted, modified, replaced, combined, and so on.

Alternatively, in other or modified embodiments, the light source 56 includes a light emitting unit and a light converter, the structure and function of the light converter are substantially the same as the light converter 362, and the structure and function of the light emitting unit are substantially the same as the light emitting unit 361.

In the fingerprint detection, the ridges 1100 of the fingerprint 1000 are in contact with the upper surface of the light guide unit, and the valleys 1200 of the fingerprint 1000 are opposite to the upper surface of the light guide unit through the spacer. The detection beam 501 is diffusely reflected at the ridge 1100 and totally reflected opposite the valley 1200. The detection light beam 501 diffusely reflected at the ridge 1100 passes through the transparent region 520 of the protection layer 52, the optical glue 53, and the display module 51 to reach the detection module 59. The detection module 59 receives the detection beam 501 and converts it into an electrical signal, which can be used for image generation or detection of the fingerprint 1000.

Optionally, in some embodiments, the detection module 59 may further include a processor and a memory, and the processor may obtain fingerprint information of the user according to the received detection light beam 501, such as, but not limited to, a fingerprint image including ridge/valley contrast. The memory stores the biological characteristic information data in advance, and the processor can compare the acquired fingerprint information with the pre-stored fingerprint information data, so that fingerprint detection and identification are realized. By detecting and identifying the fingerprint, the optical detection device 5 can be used for locking or unlocking electronic products, verifying online payment service, verifying the identity of a financial system or a public security system, verifying the passing of an access control system and other various products and application scenes.

In the present invention, the optical detection device 5 may be a mobile phone, a tablet computer, an intelligent watch, an augmented reality/virtual reality device, a human body motion detection device, an auto-pilot car, an intelligent home device, a security device, an intelligent robot, or a combination thereof.

It is to be noted that the close proximity appearing in the description of the present invention and the claims may mean, for example but not limited to: bonded together by lamination, either in close proximity or close proximity with a gap, or tightly connected by an optical medium. The invention is not limited in this regard.

The optical detection device 5 of the present invention uses a light guide unit as a light guide medium for the detection light beam 501, and the detection light beam 501 is incident into the light guide unit at an angle satisfying a total reflection transmission condition and can be irradiated to the preset region P5. The preset area P5 is an irradiation area of the detection light beam 501 on the upper surface 511 of the light guide unit, and the view field area V5 is an area touched by a finger of a user during fingerprint detection.

The preset region P5 and the field of view region V5 have an overlapping region, and the detection beam 501 irradiated to the overlapping region is equivalent to the ridge 1100 capable of being directly irradiated to the fingerprint 1000. The detection light beam 501 irradiated to the non-overlapping area where the preset area P5 does not overlap with the field of view area V5 can reach the field of view area V5 after being transmitted by total reflection for a plurality of times.

Since there is an air space between the valleys 1200 and the field of view region V5 of the fingerprint 1000, the detection beam 501 is totally reflected at a position where the field of view region V5 and the valleys 1200 are opposed, and can be transmitted by total reflection within the light guide unit. Due to the direct contact between the ridge 1100 of the fingerprint 1000 and the preset area, the detection light beam 501 is diffusely reflected at the contact position between the field area V5 and the ridge 1100, and a part of the diffusely reflected detection light beam 501 can be received by the detection module 59 after passing through the lower surface of the transparent area 520. The detection beam 501 is non-collimated light, including but not limited to non-collimated near infrared light.

The detection module 59 receives the detection light beam 501 subjected to diffuse reflection to perform imaging, and because the light beam characteristic of diffuse reflection is divergent towards all directions in space, at least part of the detection light beam 501 subjected to diffuse reflection is emitted from the lower surface of the light guide unit, at least part of the detection light beam 501 emitted from the lower surface of the light guide unit can be received by the detection module 59, and the detection light beam 501 can have different incident angles when entering the detection module 59.

Therefore, the detection module 59 may be disposed substantially directly below the field of view region V5 to receive the diffusely reflected detection light beam 591. Of course, the detecting module 59 may be disposed at any position of the optical detecting device 5, as long as the detecting module 59 can receive the detecting light beam 501 diffusely reflected from the ridge 1100, which is within the protection scope of the present invention. The invention is not limited in this regard. The horizontal distance between the detection module 59 and the light source 56 may be less than or equal to the horizontal distance between the field of view region V5 and the light source 56. In this embodiment, the horizontal distance between the detection module 59 and the light source 56 is about 10-15 mm. Of course, alternatively, in some embodiments, the detection module 59 may be disposed adjacent to the light source 56, and the horizontal distance between the detection module 59 and the light source 56 may be less than 10 mm, 8 mm, or 5 mm.

When the detection module 59 is located below the view field region V5, the path of the detection light beam 501 transmitted in the light guide unit is short, and the detection light beam 501 does not need to be transmitted in the other regions of the light guide unit by total reflection. Therefore, the energy loss of the detection beam 501 received by the detection module 59 is small. In addition, as described above, the size or volume of the detection module 59 is small, so that the requirement of being disposed inside an electronic product such as a mobile phone can be satisfied.

Of course, collimated light may also be used as the detection beam in some embodiments. It will be appreciated that if a collimated beam is used as the detection beam, this results in the width of the corresponding predetermined region being the same as the width of the light entrance region. However, since the light incident region 513 is located on the lower surface of the non-transparent region of the protection layer 52, the transparent region 520 faces the display module 51, the non-transparent region 510 and the display module 51 are not arranged in a right-to-right manner, or most of the non-transparent region 510 and the display module 51 are not arranged in a right-to-right manner. The display module 51 is used for displaying images, and the transparent region 520 of the protection layer 52 can transmit visible light but the non-transparent region 510 of the protection layer 52 has a very low transmittance for visible light. That is, the non-transparent region 510 is a portion outside the visible display region of the optical detection device 5, and the portion outside the visible display region is generally referred to as a frame region. Since the electronic products capable of displaying images that are mainstream at present are all pursuing a full screen and a narrow frame, the frame region of the optical detection device 5 is narrow, the width of the non-transparent region 510 is very small, and the width of the light incident region 513 is also very small. Accordingly, the width of the preset area is also very small. Due to the parallel transmission characteristics of collimated light, at this time, the following problems are likely to occur: there are some positions on the field of view region V5 where no detection beam can directly impinge, nor can the detection beam reach the field of view region V5 after total reflection. This condition of the field of view region V5 results in portions of the fingerprint corresponding to these locations not being detectable. Thus, although a collimated light detection beam can also be used for underscreen fingerprint detection or optical imaging, it has the major disadvantage that it is inferior to the non-collimated light detection beam 501 in fingerprint detection efficiency and imaging quality.

Therefore, the optical detection device 5 and the modified embodiment of the present invention employ the non-collimated detection beam 501, and the non-collimated detection beam 501 can directly irradiate the whole preset region P5, so that the detection beam 501 directly reaching the ridge of the fingerprint has more energy, and can detect the fingerprint information of the whole preset region P5. The optical detection device 5 and the modified embodiment thereof of the invention have better fingerprint detection effect. Similarly, the

optical detection devices

1, 3, 4, and 5 and the modified embodiments thereof according to the present invention have a good fingerprint detection effect.

Of course, in other embodiments, a non-collimated detection beam 501 may also be used, and the non-collimated detection beam 501 passes through the light guiding unit of the optical detection device 5 after being totally reflected and can be further received by a detection module, in this case, it is equivalent to the optical detection device 5 receiving the totally reflected detection beam 501 for imaging and detection. For example, the non-collimated detection light beam 501 totally reflects in the preset area P5 and then exits the light guiding unit of the optical detection apparatus 5 and is further received by the detection module. However, in these embodiments, an optical element with a larger refractive index needs to be disposed on the lower surface of the light guide unit, so that the detection light beam 501 can be emitted from the lower surface after being totally reflected on the upper surface of the light guide unit. The provision of the optical element necessarily leads to an increase in the cost and complexity of assembly of the optical detection device 5. Moreover, in these embodiments, since the detection light beam 501 is non-collimated light, which has a certain divergence angle when projected on the preset region P5, the width of the preset region P5 is larger than the width of the light incident region 513. Accordingly, the reflected light of the detection light beam 501 after being totally reflected in the preset region P5 also has a certain divergence angle, and therefore, it can be understood that the detection light beam 501 totally reflected to the lower surface of the light guide unit exits from the lower surface, and the exiting detection light beam 501 correspondingly has an exiting region with a width larger than that of the preset region P5 on the lower surface. Therefore, the fingerprint image formed by the detection beam 501 totally reflected to the lower surface and emitted will have a relatively serious amplification phenomenon, thereby causing the fingerprint image to be distorted. In addition, the area of the emitting area of the detection light beam 501 on the lower surface of the light guide unit is large, and accordingly, a detection module for receiving the emitted detection light beam 501 needs a large volume and area to receive the detection light beam 501 coming out of the emitting area. For example, but not limited to, the detection module requires a larger photosensitive area, or a larger volume of lens, etc. For example, the detection module needs to be provided with a lens with a larger volume, and the cross-sectional area of the lens needs to be not smaller than the area of the preset region P5; or the detection module needs to be provided with a relatively large-sized image sensor, and the area of the photosensitive region of the image sensor, which receives the detection light beam 501, needs to be not smaller than the area of the preset region P5. Thus, in order to set the detection module, even the original space of other components needs to be occupied, which all affect the overall volume, cost and assembly of the optical detection device 5, and cannot be applied to the requirements of the inside of electronic products such as mobile phones.

Furthermore, according to the optical principle of total reflection, the horizontal distance between the exit area of the totally reflected detection light beam 501 on the lower surface of the light guide unit and the light source 56 is greater than the horizontal distance between the preset area P5 and the light source 56. Moreover, the emitting directions of the detecting light beams 501 emitted from the emitting areas follow the reflection and refraction principles, so that the detecting modules receiving the detecting light beams 501 need to be arranged on the corresponding emitting light paths to ensure the receiving and imaging effects. Therefore, the horizontal distance between the detection module and the light source 56 is greater than the horizontal distance between the predetermined area P5 and the light source 56. The detection module needs to be located at a side of the preset region P5 away from the light source 56, and the detection light beam 501 needs to be transmitted through a further path inside the light guiding unit for exiting, and needs to be transmitted outside the preset region P5 of the light guiding unit. In this way, if the light guide unit between the preset region P5 and the output region is broken or damaged, the detection light beam 501 cannot be smoothly output from the output region on the lower surface of the light guide unit by total reflection.

In addition, in some embodiments, the preset region P5 and the view field region V5 have no overlap or have a small overlap, so that fingerprint detection almost completely depends on the detection light beam of the preset region P5 being totally reflected and then being irradiated to the view field region V5, and once the light guide unit or the protective layer between the light source and the preset region P5 breaks or is damaged, or the light guide unit or the protective layer between the preset region P5 and the view field region V5 breaks or is damaged, the fingerprint detection effect is reduced, or even normal detection cannot be performed. In other words, when the area outside the preset area P5 of the light guide unit is damaged, the receiving and imaging of the detection light beam are affected, and the user experience is reduced.

Therefore, the detection module 59 of the fingerprint detection device 5 of the present invention receives the detection light beam 501 that is emitted after being diffusely reflected at the ridge 1100. Since the characteristic of diffuse reflection is that the detection light beam is reflected to all directions in space, no additional optical element is needed to guide the detection light beam out of the light guide unit, and the detection light beam 501 reflected by the diffusion received by the detection module 59 does not have the problem of image amplification or deformation. The volume of the detection module 59 of the present invention can be made smaller, and the area of the light sensing area of the detection module 59 receiving the detection light beam 501 can be smaller than the area of the field of view area V5. Optionally, in some embodiments, the detection module 59 includes an image sensor and an ultramicro lens located above the image sensor, where the ultramicro lens is configured to converge the detection light beam 501 emitted from the light guide unit after being subjected to diffuse reflection onto the image sensor, and the image sensor is configured to convert the detection light beam 501 into a corresponding electrical signal. The vertical projection of the subminiature lens and the image sensor on the upper surface of the light guide unit is located within the field of view region V5, and the area of the vertical projection is smaller than the area of the field of view region V5.

Optionally, in some embodiments, the light guide unit includes a first surface and a second surface, and the first surface is disposed opposite to the second surface, where the first surface is the upper surface and the second surface is the lower surface. Of course, alternatively, in some embodiments, the second surface may also be a side surface of the light guide unit, and the first surface is the upper surface of the light guide unit, for example, but not limited to, the second surface is connected between the upper surface and the lower surface of the light guide unit, and forms an acute angle with the upper surface. The light source is arranged on one side of the second surface, and the light incident region is arranged on the second surface. The embodiment of the invention does not limit the positions of the first surface and the second surface of the light guide unit, and only needs to detect that the light beam enters the light guide unit from the second surface and can be totally reflected in the light guide unit, which belongs to the protection scope of the invention.

The light source and the detection module of the optical detection device are both arranged below the light guide unit. The light source emits a non-collimated detection beam, the detection beam is directly projected to an overlapping area of a preset area and a field area, and the detection beam passing through the non-overlapping area of the preset area is transmitted to the field area through total reflection. When the fingerprint contacts the field of view, the detection light beam is diffused and reflected at the ridge and then is transmitted out of the light guide unit and can be received by the detection module. The detection module receives diffuse reflection's detection light beam and converts the signal of telecommunication into to acquire fingerprint information, thereby can realize fingerprint detection, fingerprint optical imaging, fingerprint identification etc. under the screen or in the screen. The optical detection device has better fingerprint detection effect

The above-mentioned embodiments or modified embodiments and corresponding modified arrangements of the present invention can also be applied to other embodiments disclosed in the present invention, such as the structures and positions of the light guiding unit, the display module, the light source, the light converter, the light emitting unit, the light incident region, the predetermined region, the field of view region, etc., and thus the embodiments and their replacement, modification, combination, separation, extension, omission, etc. all belong to the scope of the present invention.

It should be noted that the light exit surface, the light incident surface, and the like which may appear in the description of the present invention may be a real surface which actually exists, or may be an imaginary surface, which does not affect the implementation of the technical solution of the present invention, and all of them belong to the scope of the present invention. In addition, the terms "overlap", "overlap" and "overlapping" as may appear in the description of the present invention should be understood to have the same meaning and may be substituted for each other.

It should be noted that, part or all of the embodiments of the present invention, and part or all of the modifications, replacements, alterations, splits, combinations, extensions, etc. of the embodiments are considered to be covered by the inventive idea of the present invention without creative efforts, and belong to the protection scope of the present invention.

Any reference in this specification to "one embodiment," "an embodiment," "example embodiment," etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature or structure is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature or structure in connection with other ones of the embodiments.

The orientations and positional relationships indicated by "length", "width", "upper", "lower", "left", "right", "front", "rear", "back", "front", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, which may appear in the present specification, are based on the orientations and positional relationships shown in the drawings, and are only for convenience in describing embodiments of the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Like reference numbers and letters refer to like items in the figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Meanwhile, in the description of the present invention, the terms "first", "second", and the like are used only for distinguishing the description, and are not to be construed as indicating or implying relative importance. In the description of the present invention, "plurality" or "a plurality" means at least two or two unless explicitly specifically defined otherwise. In the description of the present invention, it should be further noted that, unless otherwise explicitly stated or limited, the terms "disposed," "mounted," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; either directly or indirectly through intervening media, or may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. An optical inspection apparatus, comprising:

the light guide unit comprises a first surface and a second surface which are different;

the detection module is positioned below the light guide unit, the first surface is the surface of one side, back to the detection module, of the light guide unit, the detection module is used for receiving detection light beams emitted from the light guide unit, and the detection module is provided with a view field area on the first surface; and

the light source is used for projecting the detection light beams to the inside of the light guide unit through the second surface, the detection light beams entering the inside of the light guide unit can be transmitted in the light guide unit in a total reflection manner, a region where the detection light beams entering the inside of the light guide unit from the light source are transmitted and reach the first surface for the first time is defined as a preset region, an overlapping region exists between the preset region and the view field region, and the area proportion of the overlapping region in the view field region is greater than or equal to 30%;

when no finger of a user is contacted on the preset area, the detection light beam is totally reflected in the field of view area;

when a user finger contacts the field of view area, the detection light beam is subjected to diffuse reflection at the fingerprint ridge contacting the field of view area, the detection light beam is subjected to total reflection at the position opposite to the fingerprint valley in the field of view area,

at least part of the detection light beams subjected to diffuse reflection penetrates out of the light guide unit to be received by the detection module, and the detection module converts the received detection light beams into corresponding electric signals to obtain fingerprint information.

2. The optical inspection device of claim 1, wherein the predetermined area is the field of view area; or, the preset region is located in the field of view region, and the area of the preset region is smaller than that of the field of view region; or, the field of view region is located in the preset region, and the area of the field of view region is smaller than that of the preset region; or, there is an overlap between part of the preset region and part of the field of view region; defining a part of the preset area which is not overlapped with the field of view area as a non-overlapped area, wherein at least part or all of the non-overlapped area is adjacent to the light source compared with the overlapped area.

3. The optical inspection device according to claim 2, wherein the inspection beam that can be totally reflected on the field of view area when no finger of a user is in contact with the field of view area includes an inspection beam that reaches the field of view area after being transmitted from the non-overlapping area through a plurality of total reflections, or/and an inspection beam that reaches the overlapping area for the first time after entering the interior of the protective layer from the light source and satisfies total reflection at the overlapping area.

4. The optical inspection device according to claim 1, wherein the second surface is disposed opposite to the first surface, a region where the light source enters at the second surface is defined as a light entrance region, and the inspection light beam enters the light guide unit from the light entrance region and is transmitted to the predetermined region; the light source is arranged in the light guide unit, and the light source is arranged in the light guide unit and is used for directly projecting the detection light beam to the overlapping area through the second surface.

5. The optical inspection device according to claim 1, wherein the light guide unit includes an upper surface and a lower surface opposite to each other, the inspection module is disposed below the lower surface for receiving the inspection light beam emitted from the lower surface, and the first surface is the upper surface; the second surface is the lower surface, or the second surface is an inclined plane or a side surface of the light guide unit, and the inclined plane or the side surface is located between the upper surface and the lower surface.

6. The optical inspection device according to claim 1, wherein the light source comprises a light emitting unit and a light converter, the light emitting unit is configured to emit a non-collimated inspection beam, and the light converter is configured to convert an angle at which the non-collimated inspection beam enters the light guiding unit, so that the inspection beam can directly irradiate the predetermined area after entering the light guiding unit and can be transmitted by total reflection in the light guiding unit.

7. The optical inspection device as claimed in claim 6, wherein the light converter is disposed between the light-emitting surface of the light-emitting unit and the second surface, or the light converter is integrally formed with the light-guiding unit, and the light-entering region of the second surface of the inspection beam is a partial surface of the light converter.

8. The optical inspection device according to claim 1, further comprising a display device, wherein the display device comprises a protective layer and a display module, the protective layer comprises an upper surface and a lower surface which are oppositely arranged, the display module is arranged on one side of the lower surface of the protective layer for displaying images, and the inspection module is used for receiving the inspection light beam emitted from the light guide unit through at least a part of the display module; the upper surface of the protective layer is the first surface of the light guide unit.

9. The optical inspection device of claim 8, wherein the protection layer includes a transparent region and a non-transparent region located in the transparent region, the display module is configured to emit a visible light beam through the transparent region, the light source is located in the non-transparent region in the light incident region of the second surface, and the wavelength of the inspection light beam is different from the wavelength of the visible light beam.

10. The optical inspection device of claim 8, wherein the display device further comprises an optical adhesive for connecting the protection layer and the display module, and the light guide unit comprises or is the protection layer, or the light guide unit comprises or is the protection layer and the optical adhesive, or the light guide unit comprises or is at least a portion of the protection layer, the optical adhesive, and the display module.

11. The optical inspection device of claim 10, wherein the protective layer includes a transparent substrate, the optical glue has a refractive index greater than or equal to a refractive index of the transparent substrate, and the transparent substrate has a refractive index greater than a refractive index of air.

12. The optical inspection device as claimed in claim 8, wherein the area of the display module displaying the image is defined as a display area, and the area around the display area where the image cannot be displayed is defined as a non-display area; the field of view region is located directly above a local region of the display region.