CN108388827B - Fingerprint imaging module and electronic equipment - Google Patents
Fingerprint imaging module and electronic equipment Download PDFInfo
- Publication number
- CN108388827B CN108388827B CN201710063822.8A CN201710063822A CN108388827B CN 108388827 B CN108388827 B CN 108388827B CN 201710063822 A CN201710063822 A CN 201710063822A CN 108388827 B CN108388827 B CN 108388827B
- Authority
- CN
- China
- Prior art keywords
- light
- imaging module
- filter layer
- protective cover
- light source
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V40/00—Recognition of biometric, human-related or animal-related patterns in image or video data
- G06V40/10—Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
- G06V40/12—Fingerprints or palmprints
- G06V40/13—Sensors therefor
Abstract
The utility model provides a fingerprint imaging module and electronic equipment, wherein the fingerprint imaging module includes: a light source for generating incident light; the protective cover plate is positioned on the light source, the protective cover plate is provided with a first surface facing the light source, the first surface is covered with a filter layer, and the refractive index of the filter layer material is greater than that of the protective cover plate material; the sensing surface transmits incident light of the filter layer and the protective cover plate, and the incident light is reflected on the sensing surface to form reflected light carrying fingerprint information; an image sensor for collecting the reflected light to obtain a fingerprint image. The technical scheme of the invention can reduce the components of the large-angle light in the formed reflected light, thereby being beneficial to improving the problem of fingerprint image amplification and reducing the phenomenon of fingerprint image deformation.
Description
Technical Field
The invention relates to the field of fingerprint imaging, in particular to a fingerprint imaging module and electronic equipment.
Background
The fingerprint identification is to compare the fingerprint image with the existing fingerprint information in the fingerprint identification system after the human fingerprint image is collected, so as to realize the identity identification. Due to the convenience of use and the uniqueness of human fingerprints, fingerprint identification technology has been widely applied to various fields, such as: the security inspection field such as public security bureau, customs, etc., the entrance guard system of buildings, and the consumer goods field such as personal computer and mobile phone, etc.
In the fingerprint imaging technology adopted by fingerprint identification, one is to collect human fingerprint images by an optical method: generating incident light by a light source; the incident light is projected to the surface layer of the finger and forms reflected light with fingerprint information through the reflection of the finger; and receiving the reflected light by an image sensor to obtain a fingerprint image.
But the problem of deformation appears easily in the fingerprint image that the fingerprint imaging module among the prior art obtained.
Disclosure of Invention
The invention provides a fingerprint imaging module and electronic equipment to solve the problem of fingerprint image deformation.
In order to solve the above problems, the present invention provides a fingerprint imaging module, comprising:
a light source for generating incident light; the protective cover plate is positioned on the light source, the protective cover plate is provided with a first surface facing the light source, the first surface is covered with a filter layer, and the refractive index of the filter layer material is greater than that of the protective cover plate material; the sensing surface transmits incident light of the filter layer and the protective cover plate, and the incident light is reflected on the sensing surface to form reflected light carrying fingerprint information; an image sensor for collecting the reflected light to obtain a fingerprint image.
Optionally, the refractive index of the filter layer material is greater than 1.52.
Optionally, the filter layer is made of titanium pentoxide, silicon nitride, silicon oxide, aluminum oxide, or indium tin oxide.
Optionally, the filter layer has a thickness in a range of 50 nm to 100 nm.
Optionally, the filter layer is a film layer formed by a coating process.
Optionally, the coating process includes: evaporation process, magnetron sputtering process, physical vapor deposition process or chemical vapor deposition process.
Optionally, the light source is located at one side of the image sensor, and a space is provided between the light source and the image sensor; the protective cover plate extends to the image sensor; the filter layer covers at least a first face between the image sensor and the light source.
Optionally, the fingerprint imaging module further includes: and the adhesive layer is used for realizing the connection between the image sensor and the protective cover plate.
Optionally, the filter layer extends between the image sensor and the protective cover plate; the bonding layer is used for realizing the joint between the image sensor and the filter layer.
Optionally, the material of the adhesive layer is transparent optical glue.
Optionally, the light source has a light emitting surface; the fingerprint imaging module further comprises a light guide layer located on the light source light emitting surface and used for conducting incident light.
Optionally, the light guide layer has an incident surface and an exit surface; the incident surface of the light guide layer is attached to the light emitting surface of the light source; and the emergent surface of the light guide layer is attached to the surface of the filter layer.
Optionally, the light guide layer is made of transparent optical cement.
Optionally, the light source has a light emitting surface; the light emitting surface faces the image sensor.
Optionally, an included angle between the surface of the filter layer facing the light source and the light emitting surface of the light source is in a range from 60 degrees to 90 degrees.
Optionally, the material of the protective cover plate is glass.
Optionally, the light source is a light emitting diode.
Correspondingly, the invention also provides an electronic device, comprising: the invention discloses a fingerprint imaging module.
Optionally, the electronic device further includes: a glass cover plate; the glass cover plate is the protection cover plate.
Compared with the prior art, the technical scheme of the invention has the following advantages:
because the refractive index of the material of the filter layer is greater than that of the material of the protective cover plate, the incident light penetrates through the filter layer and the protective cover plate to be an optically dense medium and enters an optically sparse medium, and when the incident angle of the incident light is too large, the incident light can be totally reflected at the interface of the filter layer and the protective cover plate. The filter layer can enable large-angle incident light to be totally reflected, and only small-angle incident light can be transmitted, namely, the filter layer can effectively reduce the transmission of the large-angle incident light, so that components of the large-angle light projected onto the sensing surface are reduced, and the components of the large-angle light in formed reflected light are reduced, so that the components of the small-angle light in the reflected light collected by the image sensor are higher, the problem of fingerprint image amplification is favorably solved, and the phenomenon of fingerprint image deformation is favorably reduced.
Drawings
FIG. 1 is a schematic cross-sectional view of a fingerprint imaging module;
FIG. 2 is a schematic cross-sectional view of a fingerprint imaging module according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of an optical path of the filter layer in the embodiment shown in FIG. 2 for filtering out large-angle incident light;
FIG. 4 is a schematic diagram of the optical path of the reflected light formed by the small-angle incident light transmission filter layer and the protective cover in the embodiment of FIG. 2;
FIG. 5 is a schematic cross-sectional view of another embodiment of a fingerprint imaging module according to the present invention;
fig. 6 is a schematic cross-sectional view of an electronic device according to an embodiment of the invention.
Detailed Description
Known by the background art, there is the problem that deformation appears easily in the fingerprint image that obtains in the fingerprint imaging module among the prior art. The reason that now combines its fingerprint image deformation problem of section structure schematic diagram analysis of a fingerprint imaging module:
referring to fig. 1, a schematic cross-sectional structure diagram of a fingerprint imaging module is shown.
As shown in fig. 1, the fingerprint imaging module includes: a protective cover 11 and a light source 12 and an image sensor 13 located below the protective cover 11; in the process of collecting the fingerprint image, a finger 10 presses on the surface of the protective cover plate 11; incident light generated by the light source 12 is projected to an interface between the finger 10 and the protective cover 11, and is reflected and refracted at the interface, so as to form reflected light carrying fingerprint information, and the reflected light is projected to the image sensor 13; the image sensor 13 collects the reflected light, and converts an optical signal of the reflected light into an electrical signal to obtain a fingerprint image.
In order to reduce the volume of the fingerprint imaging module, the light source 12 is often a light emitting diode, that is, the light source 12 is a point light source, so that the incident light generated by the light source has a certain divergence angle, and the formed reflected light also has a certain divergence angle accordingly.
As shown in fig. 1, the range of the incident light irradiated to the interface of the finger 10 and the protective cover 11 has a first distance d 1; and the range of the formed reflected light projected to the image sensor 13 has a second distance d 2. Since the reflected light has a certain divergence angle, the second distance d2 is greater than the first distance d1, that is, the fingerprint image obtained by collecting the reflected light is enlarged to some extent compared with the fingerprint on the surface of the real finger 10, and the enlargement ratio is d2/d 1.
When the fingerprint imaging module is applied to electronic equipment such as a mobile phone, the appearance color of the fingerprint imaging module needs to be adapted to the appearance design of the electronic equipment, especially, the area above the image sensor 13 may become a part of the appearance of the electronic equipment, so that the fingerprint imaging module is colored, and the appearance color of the fingerprint imaging module is adapted to the appearance of the point shooting equipment. It is right when the fingerprint imaging module is colored, protection apron 11 orientation the surface of light source 12 can coat printing ink, and the light transmissivity of most printing ink is relatively poor, to transmitting extremely incident light on the protection apron 11 can form stronger scattering.
In order to improve the transmittance of the incident light, as shown in fig. 1, one method is to dispose a light source 12 at one side of the image sensor 13 so that the incident light is obliquely projected onto the protective cover 11, the incident light being transmitted from the protective cover 11 not coated with ink.
The light source 12 is disposed on one side of the image sensor 13, so that only large-angle incident light can be projected to the interface between the finger 10 and the protective cover 11, that is, components of large-angle light in the incident light at the interface between the finger 10 and the protective cover 11 are increased, and thus, the components of the large-angle light in the formed reflected light are more, and a fingerprint image formed by collecting the reflected light is relatively severely amplified, thereby causing deformation of the fingerprint image.
In order to solve the technical problem, the invention provides the fingerprint imaging module, the filter layer is arranged on the first surface of the protective cover plate, and the filter layer can filter out incident light with a large angle, so that the problem of fingerprint image amplification is improved, and the phenomenon of fingerprint image deformation is favorably reduced.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.
Referring to fig. 2, a schematic cross-sectional structure diagram of a fingerprint imaging module according to an embodiment of the invention is shown.
Fingerprint formation of image module includes:
a light source 110 for generating incident light; a protective cover plate 120 located on the light source 110, wherein the protective cover plate 120 has a first surface facing the light source 110, the first surface is covered with a filter layer 121, and a refractive index of a material of the filter layer 121 is greater than a refractive index of a material of the protective cover plate 120; a sensing surface 122, which transmits the incident light of the filter layer 121 and the protective cover plate 120, and reflects on the sensing surface 122 to form reflected light carrying fingerprint information; an image sensor 130 for collecting the reflected light to obtain a fingerprint image.
Since the refractive index of the material of the filter layer 121 is greater than that of the material of the protective cover plate 120, the incident light passes through the filter layer 121 and the protective cover plate 120 as an optically dense medium and enters an optically sparse medium, so when the incident angle of the incident light is too large, the incident light may be totally reflected at the interface between the filter layer 121 and the protective cover plate 120. The filter layer 121 can totally reflect the incident light with a large angle, and only the incident light with a small incident angle is transmitted, that is, the filter layer 121 can effectively reduce the transmission of the incident light with a large angle, so as to reduce the components of the light with a large angle projected onto the sensing surface 122, and reduce the components of the light with a large angle in the formed reflected light, so that the components of the light with a small angle in the reflected light collected by the image sensor 130 are higher, which is beneficial to improving the problem of fingerprint image amplification and reducing the phenomenon of fingerprint image deformation.
The technical scheme of the fingerprint imaging module is described in detail below by combining the light path diagram.
The light source 110 is used to generate incident light. The image sensor 130 is configured to collect the reflected light and obtain the fingerprint image according to the reflected light. Specifically, in this embodiment, the light source 110 is a light emitting diode.
The light source 110 has a light emitting surface from which incident light is emitted at a certain divergence angle.
The sensing surface 122 is for receiving a touch.
When fingerprint image collection is performed, a finger presses the sensing surface 122, transmission incident light is projected to the sensing surface 122, and reflection and refraction occur at a contact position of the finger and the sensing surface 122, so that reflected light carrying fingerprint information is formed.
The protective cover 120 is positioned on the light source 110 to protect the light source 110.
In order to improve the integration of the electronic device, in the embodiment, the light source 110 is located on one side of the image sensor 130 in a plane parallel to the surface of the protective cover 120, and the image sensor 130 and the light source 110 have a space therebetween. The incident light 111 generated by the light source 110 is obliquely projected onto the protective cover 120 between the light source 110 and the image sensor 130.
The incident light 111 projected onto the protective cover 120 includes a small-angle incident light 111a having a small incident angle and a large-angle incident light 111b having a large incident angle. The angle of the reflected light formed by the small-angle incident light 111a is small, so that the amplification ratio of the fingerprint image obtained according to the reflected light formed by the small-angle incident light 111a is small; the angle of the reflected light formed by the large-angle incident light 111b is large, so the enlargement ratio of the fingerprint image obtained from the reflected light formed by the large-angle incident light 111b is large.
It should be noted that, as shown in fig. 2, in this embodiment, the fingerprint imaging module further includes: the light guide layer 140 is located on the light emitting surface of the light source 110 and is used for guiding the incident light 111.
Specifically, the light guide layer 140 is filled between the light source 110 and the image sensor 130, and the light guide layer 140 includes an incident surface and an exit surface. The incident surface of the light guide layer 140 is attached to the light exit surface of the light source 110, so that as much incident light 111 as possible is projected into the light guide layer 140 and transmitted by the light guide layer 140, thereby improving the utilization rate of the incident light 111. The exit surface of the light guide layer 140 faces the protective cover 120, so that as much incident light transmitted through the light guide layer 140 is projected onto the protective cover 120 as possible.
In this embodiment, the light guide layer 140 is made of transparent optical adhesive, so the light guide layer 140 can also be used to fix the light source 110.
Specifically, the protective cover 120 may be a glass cover, that is, the material of the protective cover 120 is glass. In order to improve the protection capability of the protective cover 120, the material of the protective cover 120 may be tempered glass.
The protective cover 120 has a first surface facing the light source 110 and a second surface opposite to the light source 110.
The filter layer 121 on the first surface is used for filtering large-angle incident light 111b with a large incident angle in the incident light 111 and transmitting small-angle incident light 111a with a small incident angle, so that components of large-angle light in the incident light which transmits the filter layer 121 and the protective cover plate 120 are reduced, the proportion of small-angle light in the incident light which transmits the filter layer 121 and the protective cover plate 120 is increased, and the components of the large-angle light in the formed reflected light are reduced, so that the components of the small-angle light in the reflected light collected by the image sensor 130 are high, the problem of fingerprint image amplification is favorably solved, and the phenomenon of fingerprint image deformation is favorably reduced.
It should be noted that in this embodiment, the second surface of the protective cover 120 is used for receiving a touch, that is, the second surface of the protective cover 120 is the sensing surface 122. However, this is merely an example, and in other embodiments of the present invention, when the protective cover is further covered with another film structure, the sensing surface may also be a surface of the other film structure.
Referring to fig. 3 and 4, fig. 3 is a schematic diagram of an optical path of the filter layer 121 filtering out the large-angle incident light 111b in the embodiment shown in fig. 2, and fig. 4 is a schematic diagram of an optical path of the small-angle incident light 110a transmitting the filter layer 121 and the protective cover plate 120 to form reflected light in the embodiment shown in fig. 2.
Note that light guiding layer 140 is omitted from fig. 3 and 4 for clarity of illustration.
The refractive index of the material of the filter layer 121 is greater than the refractive index of the material of the protective cover plate 120. The incident light 111 is transmitted from the filter layer 121 to the protective cover plate 120, and is an optically dense medium and an optically sparse medium, so as shown in fig. 3, the incident light 111b with a large angle is totally reflected at the interface between the filter layer 121 and the protective cover plate 120, and is filtered out.
As shown in fig. 4, the small-angle incident light 111a is refracted at the interface between the filter layer 121 and the protective cover 120, and is transmitted. Therefore, the filter layer 121 can effectively increase the proportion of the small-angle incident light 111a in the reflected light that transmits through the filter layer 121 and the protective cover plate 120, and can effectively increase the proportion of the small-angle light in the formed reflected light, which is beneficial to improving the amplification problem of the obtained fingerprint image.
For example, after the small-angle incident light 111a transmits through the filter layer 121 and the protective cover 120, the range projected to the interface between the finger 100 and the protective cover 120 has a first distance D1; the range in which the formed reflected light is projected to the image sensor 130 after transmitting the protective cover 120 and the filter layer 121 has a second distance D2. The fingerprint image obtained by collecting the reflected light is magnified at a scale of D2/D1 as compared to the fingerprint of the surface of the real finger 100. Because the reflected light is formed by the small-angle incident light 111a, the incident angle of the reflected light projected to the surface of the image sensor 130 is relatively small, so that the amplification ratio can be effectively reduced, the problem of amplification of the fingerprint image is favorably solved, and the phenomenon of deformation of the fingerprint image is reduced.
It should be noted that, as shown in fig. 2, in the present embodiment, the fingerprint imaging module further includes a light guide layer 140 located on the light emitting surface of the light source 110. The light guide layer 140 is made of transparent optical adhesive, so that the refractive index of the light guide layer 140 is close to that of the protective cover plate 121 and is smaller than that of the filter layer 121, and therefore, the incident light 111 is transmitted from the light guide layer 140 and enters the filter layer 121 as an optically thinner medium and enters an optically denser medium, so that the function of the filter layer 121 for filtering the large-angle incident light 111b is not affected by the arrangement of the light guide layer 140.
The material of the protective cover 120 is glass, and the refractive index of the material of the protective cover 120 is about 1.52, so the refractive index of the material of the filter layer 121 is greater than 1.52. In this embodiment, the material of the filter layer 121 is titanium pentoxide, so the refractive index of the material of the filter layer 121 is greater than 2. In other embodiments of the present invention, the filter layer may be made of a transparent high refractive index material such as silicon nitride, silicon oxide, aluminum oxide, or indium tin oxide.
The difference between the refractive index of the material of the filter layer 121 and the refractive index of the material of the protective cover plate 120 affects the incident angle of the incident light that is totally reflected at the interface between the filter layer 121 and the protective cover plate 120, and thus affects the ratio of the energy of the incident light filtered by the filter layer 121 to the energy of the incident light that can transmit the filter layer 121 in the incident light 111, i.e., the ratio of the light energy of the incident light 111b with a large angle to the light energy of the incident light 111a with a small angle. Therefore, by setting the materials of the protective cover plate 120 and the filter layer 121, the difference between the refractive index of the material of the protective cover plate 120 and the refractive index of the material of the filter layer 121 is within a reasonable range, and after the large-angle incident light 111b is filtered, the filter layer 121 and the small-angle incident light 111a of the protective cover plate 120 are transmitted to form reflected light with sufficient intensity, so that a clear fingerprint image with a small amplification ratio is obtained.
Note that the thickness of the filter layer 121 is not too large or too small.
If the thickness of the filter layer 121 is too small, the function of the filter layer 121 for filtering the large-angle incident light 111b is affected, and the possibility that the large-angle incident light 111b transmits the filter layer 121 is increased, so that the probability of the fingerprint image amplification phenomenon is increased; if the thickness of filter layer 121 is too big, then cause the problem of material waste, increase the technology degree of difficulty easily, also do not benefit to moreover the improvement of fingerprint imaging module integration degree. In this embodiment, the thickness of the filter layer 121 is in a range from 50 nm to 100 nm.
The filter layer 121 is a film layer formed by a plating process. By forming the filter layer 121 through a plating process, the connection strength between the filter layer 121 and the protective cover plate 120 can be improved, so that the stability of the filter layer 121 and the fingerprint imaging module is improved. Specifically, in this embodiment, the filter layer 121 is a titanium pentoxide coating film formed by a physical vapor deposition process. In other embodiments of the present invention, the filter layer may be a coating film formed by an evaporation process, a magnetron sputtering process, or a chemical vapor deposition process.
It should be noted that, in this embodiment, the light source 110 is located at one side of the image sensor 130, a space is provided between the image sensor 130 and the light source 110, and the protective cover 120 further extends to the image sensor 130 to protect the image sensor 130. The filter layer 121 covers at least the first side between the image sensor 130 and the light source 110.
Fingerprint formation of image module still includes: and an adhesive layer (not shown) between the image sensor 130 and the protective cover 120 for connecting the image sensor 130 and the protective cover 120.
The filter layer 121 extends to a portion of the first side of the protective cover plate 120 facing the image sensor 120. The adhesive layer is used to achieve adhesion between the image sensor 130 and the filter layer 121.
Specifically, the material of the bonding layer is transparent optical cement. Since the formed reflected light can be collected by the image sensor 130 only by transmitting the adhesive layer, the influence of the adhesive layer on the reflected light can be reduced and the transmittance of the reflected light can be improved by setting the material of the adhesive layer as a transparent optical adhesive.
In addition, as shown in fig. 2, in the present embodiment, the fingerprint imaging module further includes a light guide layer 140, and an exit surface of the light guide layer 140 faces the protective cover 120. Specifically, the exit surface of the light guide layer 140 is attached to the surface of the filter layer 121, so that incident light conducted by the light guide layer 140 can be projected onto the filter layer 121 as much as possible, which is beneficial to improving the energy of the incident light projected onto the filter layer 121, improving the energy of the small-angle incident light 111a transmitted through the filter layer 121 and the protective cover plate 120, improving the energy of the formed reflected light, and improving the quality of the obtained fingerprint image.
Referring to fig. 5, a schematic cross-sectional structure diagram of another embodiment of the fingerprint imaging module of the present invention is shown.
The present embodiment is the same as the previous embodiments, and the description of the present invention is omitted.
The difference between the present embodiment and the previous embodiment is that the surface of the filter layer 221 facing the light source 210 is oblique to the light emitting surface of the light source 210. The light emitting surface of the light source 210 is obliquely intersected with the surface of the filter layer 221 facing the light source 210, so that the incident angle of incident light projected onto the filter layer 221 can be reduced, the proportion of small-angle incident light in the incident light can be effectively increased, the proportion of large-angle incident light in the incident light can be reduced, the incident light energy transmitted through the filter layer 221 can be effectively improved, the utilization rate of the incident light can be improved, and the quality of the obtained fingerprint image can be improved.
It should be noted that an included angle α between the surface of the filter layer 221 facing the light source 210 and the light emitting surface of the light source 210 is not suitable to be too large or too small.
Since the reflected light needs to be transmitted above the image sensor 230 to be collected to form a fingerprint image, when performing fingerprint sensing, a position where a finger contacts the protective cover 220 is an area close to the image sensor 230, so that the incident light projected to the position where the finger contacts the protective cover 220 can form reflected light carrying fingerprint information, if an included angle between the surface of the filter layer 221 facing the light source 210 and the light emitting surface of the light source 210 is too large, the incident light projected to the position where the finger contacts the protective cover 220 is less, which is not favorable for improving the light intensity of the formed reflected light carrying fingerprint information, which may affect the cleaning degree of the obtained fingerprint image, if an included angle between the surface of the filter layer 221 facing the light source 210 and the light emitting surface of the light source 210 is too small, the function of reducing the incident angle at which the filter layer 221 projects the incident light is not obvious, which is not favorable for increasing the specific gravity of small-angle incident light, which is not favorable for reducing the specific gravity of large-angle incident light among the incident light, in this embodiment, the included angle α between the surface of the filter layer 221 facing the light source 210 and the light emitting surface.
Specifically, in this embodiment, the light source 210 has a light emitting surface and a back surface opposite to the light emitting surface; the light emitting surface faces the filter layer 121, and a distance between the filter layer 221 and the light emitting surface is smaller than a distance between the filter layer 221 and the back surface. That is, the light source 210 uses a position of a light emitting surface perpendicular to the surface of the filter layer 221 as a starting point, and the light emitting surface rotates by a certain angle in a direction toward the filter layer 221, so that the light emitting surface and the surface of the filter layer 221 are oblique.
It should be noted that, in order to fix the light source 210, the light emitting surface and the surface of the filter layer 221 facing the light source 210 are oblique, in this embodiment, the incident surface of the light guide 240 is oblique to the surface of the filter layer 221, so that the light emitting surface of the light source 210 is attached to the incident surface of the filter layer 221, thereby fixing the position and the angle of the light source 210.
Correspondingly, the invention further provides the electronic equipment.
Referring to fig. 6, a schematic cross-sectional structure diagram of an embodiment of the electronic device of the present invention is shown.
As shown in fig. 6, the electronic apparatus includes: the fingerprint imaging module 310 of the present invention.
It should be noted that, in this embodiment, the electronic device is a portable electronic device such as a mobile phone or a tablet computer; in other embodiments of the present invention, the electronic device may also be other portable electronic devices or non-portable electronic devices.
The fingerprint imaging module 310 is the fingerprint imaging module of the present invention, and the specific technical solution of the fingerprint imaging module 310 refers to the foregoing embodiments, which are not repeated herein.
In this embodiment, the electronic device includes: a glass cover plate 320. The glass cover 320 extends to the area where the fingerprint imaging module 310 is located, so the glass cover 320 is a protective cover in the fingerprint imaging module 310.
Specifically, the electronic device has a display 330, and the glass cover 320 is a glass cover for protecting the display 330. The glass cover plate 320 extends to the position where the fingerprint imaging module 310 is located, and serves as a protective cover plate of the fingerprint imaging module 310.
In summary, in the technical solution of the present invention, since the refractive index of the material of the filter layer is greater than the refractive index of the material of the protective cover plate, the incident light transmits through the filter layer and the protective cover plate as an optically dense medium and enters into an optically sparse medium, so when the incident angle of the incident light is too large, the incident light is totally reflected at the interface between the filter layer and the protective cover plate. The filter layer can enable large-angle incident light to be totally reflected, and only small-angle incident light can be transmitted, namely, the filter layer can effectively reduce the transmission of the large-angle incident light, so that components of the large-angle light projected onto the sensing surface are reduced, and the components of the large-angle light in formed reflected light are reduced, so that the components of the small-angle light in the reflected light collected by the image sensor are higher, the problem of fingerprint image amplification is favorably solved, and the phenomenon of fingerprint image deformation is favorably reduced.
Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (19)
1. The utility model provides a fingerprint imaging module which characterized in that includes:
a light source for generating incident light;
the protective cover plate is positioned on the light source, the protective cover plate is provided with a first surface facing the light source, the first surface is covered with a filter layer, and the refractive index of the filter layer material is greater than that of the protective cover plate material;
the sensing surface transmits incident light of the filter layer and the protective cover plate, and the incident light is reflected on the sensing surface to form reflected light carrying fingerprint information;
the image sensor is used for collecting the reflected light to obtain a fingerprint image, the light source is positioned on one side of the image sensor, the protective cover plate extends onto the image sensor, and the incident light generated by the light source is obliquely projected onto the protective cover plate.
2. The fingerprint imaging module of claim 1 wherein the filter layer material has a refractive index greater than 1.52.
3. The fingerprint imaging module of claim 1, wherein the filter layer is made of titanium pentoxide, silicon nitride, silicon oxide, aluminum oxide, or indium tin oxide.
4. The fingerprint imaging module of claim 1, wherein the filter layer has a thickness in a range from 50 nm to 100 nm.
5. The fingerprint imaging module of claim 1, wherein the filter layer is a film formed by a plating process.
6. The fingerprint imaging module of claim 5, wherein the coating process comprises: evaporation process, magnetron sputtering process, physical vapor deposition process or chemical vapor deposition process.
7. The fingerprint imaging module of claim 1, wherein the light source and the image sensor are spaced apart;
the filter layer covers at least a first face between the image sensor and the light source.
8. The fingerprint imaging module of claim 7, wherein the fingerprint imaging module further comprises: and the adhesive layer is used for realizing the connection between the image sensor and the protective cover plate.
9. The fingerprint imaging module of claim 8, wherein the filter layer extends between the image sensor and the protective cover plate;
the bonding layer is used for realizing the joint between the image sensor and the filter layer.
10. The fingerprint imaging module of claim 8 wherein said adhesive layer is made of a transparent optical adhesive.
11. The fingerprint imaging module of claim 1, wherein the light source has a light exit surface;
the fingerprint imaging module further comprises a light guide layer located on the light source light emitting surface and used for conducting incident light.
12. The fingerprint imaging module of claim 11, wherein the light guide layer has an entrance face and an exit face;
the incident surface of the light guide layer is attached to the light emitting surface of the light source;
and the emergent surface of the light guide layer is attached to the surface of the filter layer.
13. The fingerprint imaging module of claim 11, wherein the light guide layer is made of a transparent optical adhesive.
14. The fingerprint imaging module of claim 1, wherein the light source has a light exit surface; the light emitting surface faces the image sensor.
15. The fingerprint imaging module of claim 14, wherein an angle between a surface of the filter layer facing the light source and a light exit surface of the light source is in a range of 60 ° to 90 °.
16. The fingerprint imaging module of claim 1, wherein the protective cover is made of glass.
17. The fingerprint imaging module of claim 1, wherein the light source is a light emitting diode.
18. An electronic device, comprising: the fingerprint imaging module of any one of claims 1 to 17.
19. The electronic device of claim 18, wherein the electronic device further comprises: a glass cover plate;
the glass cover plate is the protection cover plate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710063822.8A CN108388827B (en) | 2017-02-03 | 2017-02-03 | Fingerprint imaging module and electronic equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710063822.8A CN108388827B (en) | 2017-02-03 | 2017-02-03 | Fingerprint imaging module and electronic equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108388827A CN108388827A (en) | 2018-08-10 |
| CN108388827B true CN108388827B (en) | 2020-06-26 |
Family
ID=63075977
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710063822.8A Active CN108388827B (en) | 2017-02-03 | 2017-02-03 | Fingerprint imaging module and electronic equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108388827B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3926524A4 (en) * | 2019-04-16 | 2022-04-27 | Huawei Technologies Co., Ltd. | Fingerprint identification module, screen assembly and electronic device |
| CN111095274B (en) * | 2019-07-25 | 2023-10-24 | 深圳市汇顶科技股份有限公司 | Under-screen fingerprint identification module, LCD optical fingerprint identification system and electronic equipment |
| CN110569798A (en) * | 2019-09-10 | 2019-12-13 | 京东方科技集团股份有限公司 | Line identification module, line identification device and display device |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08101914A (en) * | 1994-09-30 | 1996-04-16 | Nippondenso Co Ltd | Pattern inspection device |
| CN101484867A (en) * | 2006-08-10 | 2009-07-15 | Lg化学株式会社 | A light guide plate for system inputting coordinate contactlessly, a system comprising the same and a method for inputting coordinate contactlessly using the same |
| CN101752309A (en) * | 2008-12-02 | 2010-06-23 | 上海华虹Nec电子有限公司 | CMOS (complementary metal-oxide-semiconductor) image sensor and manufacture method thereof |
| CN202708981U (en) * | 2012-06-27 | 2013-01-30 | 惠州比亚迪实业有限公司 | Integrated optical film |
| CN204856529U (en) * | 2015-07-06 | 2015-12-09 | 上海箩箕技术有限公司 | Optical profile type fingerprint imaging system |
| CN105184248A (en) * | 2015-08-28 | 2015-12-23 | 京东方科技集团股份有限公司 | Fingerprint identification device and fingerprint identification system |
| CN106291894A (en) * | 2015-06-12 | 2017-01-04 | 联想(北京)有限公司 | A kind of detection device and electronic equipment |
-
2017
- 2017-02-03 CN CN201710063822.8A patent/CN108388827B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08101914A (en) * | 1994-09-30 | 1996-04-16 | Nippondenso Co Ltd | Pattern inspection device |
| CN101484867A (en) * | 2006-08-10 | 2009-07-15 | Lg化学株式会社 | A light guide plate for system inputting coordinate contactlessly, a system comprising the same and a method for inputting coordinate contactlessly using the same |
| CN101752309A (en) * | 2008-12-02 | 2010-06-23 | 上海华虹Nec电子有限公司 | CMOS (complementary metal-oxide-semiconductor) image sensor and manufacture method thereof |
| CN202708981U (en) * | 2012-06-27 | 2013-01-30 | 惠州比亚迪实业有限公司 | Integrated optical film |
| CN106291894A (en) * | 2015-06-12 | 2017-01-04 | 联想(北京)有限公司 | A kind of detection device and electronic equipment |
| CN204856529U (en) * | 2015-07-06 | 2015-12-09 | 上海箩箕技术有限公司 | Optical profile type fingerprint imaging system |
| CN105184248A (en) * | 2015-08-28 | 2015-12-23 | 京东方科技集团股份有限公司 | Fingerprint identification device and fingerprint identification system |
Non-Patent Citations (1)
| Title |
|---|
| 电容式触控显示模组的抗反射结构;林钢;《液晶与显示》;20150831;第30卷(第4期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108388827A (en) | 2018-08-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107527039B (en) | A kind of optical fingerprint identification device and display device | |
| CN105868742B (en) | Display module and display device | |
| WO2017063384A1 (en) | Optical fingerprint detection device and display apparatus | |
| CN108399392B (en) | Fingerprint identification structure and display device | |
| WO2018171178A1 (en) | Fingerprint identification device, control method, touch display panel and touch display device | |
| US11294152B2 (en) | Optical device for fingerprint collection | |
| CN108388827B (en) | Fingerprint imaging module and electronic equipment | |
| WO2020015436A1 (en) | Electronic device having texture detection function | |
| TW201702933A (en) | Fingerprint identification module | |
| CN111095289B (en) | Fingerprint recognition device under screen and terminal equipment | |
| US10628656B2 (en) | Image capture apparatus | |
| CN212135452U (en) | Fingerprint identification device and electronic equipment | |
| TW201419096A (en) | Touch screen systems with interface layer | |
| US20150317034A1 (en) | Water-immune ftir touch screen | |
| CN108256399A (en) | Fingerprint imaging module and electronic equipment | |
| US20200266227A1 (en) | Sensing module and image capturing apparatus | |
| CN110502145A (en) | Infrared touch-control screen system based on grating | |
| TWM575561U (en) | Image capture apparatus | |
| CN210894926U (en) | Reflective film, backlight module, liquid crystal display and fingerprint recognition device under screen | |
| CN207851841U (en) | Optical fingerprint identification system | |
| WO2019134460A1 (en) | Biological feature detection structure and manufacturing method therefor | |
| CN108921075B (en) | Light guide element | |
| TWM558941U (en) | Image capture apparatus | |
| CN213210660U (en) | Backlight module, passive light-emitting display device, under-screen biological characteristic detection system and electronic equipment | |
| CN210401953U (en) | Backlight assembly, display device and biological characteristic detection system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |