WO2017156976A1

WO2017156976A1 - Optical fingerprint sensor module

Info

Publication number: WO2017156976A1
Application number: PCT/CN2016/095823
Authority: WO
Inventors: 凌严; 朱虹
Original assignee: 上海箩箕技术有限公司
Priority date: 2016-03-16
Filing date: 2016-08-18
Publication date: 2017-09-21
Also published as: CN107203733A

Abstract

An optical fingerprint sensor module, comprising: a protection layer; an optical fingerprint sensor, the optical fingerprint sensor being located below the protection layer; and a backlight, the backlight being located below the protection layer; the backlight being located on the side of the optical fingerprint sensor; a raised optical layer being further provided between the optical fingerprint sensor and the protection layer; and light emitted from the backlight entering the protection layer from the raised optical layer. The performance of the optical fingerprint sensor module and the quality of the fingerprint image acquired by using the optical fingerprint sensor module are improved.

Description

Optical fingerprint sensor module

The present application claims priority to Chinese Patent Application No. 201610150520.X, entitled "Optical Fingerprint Sensor Module", filed on March 16, 2016, the entire contents of which is incorporated herein by reference. .

Technical field

The present invention relates to the field of optical fingerprint recognition, and in particular to an optical fingerprint sensor module.

Background technique

The fingerprint imaging recognition technology is a technique of acquiring a fingerprint image of a human body through a fingerprint sensor and then comparing it with existing fingerprint imaging information in the system to determine whether it is correct or not, thereby realizing the identity recognition technology. Due to its ease of use and the uniqueness of human fingerprints, fingerprint recognition technology has been widely used in various fields. For example, the public security bureau, customs and other security inspection areas, building access control systems, and consumer goods such as personal computers and mobile phones.

Fingerprint imaging recognition technology can be realized by various techniques such as optical imaging, capacitive imaging, and ultrasonic imaging. Relatively speaking, optical fingerprint imaging technology has relatively good imaging effect and relatively low equipment cost.

The structure of the existing optical fingerprint sensor module needs to be improved, and the performance needs to be improved.

Summary of the invention

The problem to be solved by the present invention is to provide an optical fingerprint sensor module for improving the performance of the optical fingerprint sensor module, thereby improving the quality of the fingerprint image obtained by using the optical fingerprint sensor module.

In order to solve the above problems, the present invention provides an optical fingerprint sensor module, comprising: a protective layer; an optical fingerprint sensor, the optical fingerprint sensor is located under the protective layer; and a backlight, the backlight is located under the protective layer The backlight is located in the optical a side edge of the fingerprint sensor; an optical pad upper layer is further disposed between the optical fingerprint sensor and the protective layer; and light emitted by the backlight enters the protective layer from a high layer of the optical pad.

Optionally, the upper layer of the optical pad is directly stacked with the optical fingerprint sensor and the protective layer, or the upper layer of the optical pad is directly pasted with the optical fingerprint sensor and the protective layer.

Optionally, the light emitted by the backlight enters the upper layer of the optical pad from the side of the upper layer of the optical pad, enters the protective layer from the upper layer of the optical pad, and partially reflects on the upper surface of the protective layer. The reflected light passes through the protective layer and then returns to the upper layer of the optical pad, and then enters the optical fingerprint sensor from the upper layer of the optical pad.

Optionally, the refractive index of the upper layer of the optical pad is 1.2 or more.

Optionally, there is a gap between the backlight and the optical fingerprint sensor.

Optionally, the protective layer is a single layer or a multi-layer structure, and the upper surface, the lower surface of the protective layer, the upper surface of the upper surface of the optical pad, the lower surface, and at least one surface of the upper surface of the optical fingerprint sensor With a filter layer.

Optionally, the backlight comprises at least one LED light, and the light of the LED light is near ultraviolet light, purple light, blue light, green light, yellow light, red light, near infrared light or white light.

Optionally, the backlight comprises two or more LED lights, and the two or more LED lamps are evenly distributed under the protective layer, and the light of the LED lamp is near ultraviolet light, Purple, blue, green, yellow, red, near-infrared or white.

Optionally, a light collecting lens is disposed in front of the light emitting surface of the backlight, and the collecting lens is capable of converting light of the backlight into parallel light or near parallel light, and the light of the backlight first enters the focusing The optical lens is re-entered into the side of the upper layer of the optical pad.

Optionally, the upper layer of the optical pad is configured to receive light from a side of the backlight. An antireflection layer capable of increasing the proportion of light from the backlight into the upper layer of the optical pad.

Optionally, a side of the upper layer of the optical pad is a concentrating surface, and the concentrating surface converts light emitted by the backlight into parallel light or near-parallel light.

Optionally, the concentrating surface is a sloped surface, a spherical crown surface, an ellipsoidal crown surface, a conical side surface or a pyramid side surface.

Optionally, the concentrating surface has a light antireflection layer, and the light permeable layer can increase the proportion of light of the backlight into the transparent medium.

Compared with the prior art, the technical solution of the present invention has the following advantages:

In the technical solution of the present invention, by placing the optical fingerprint sensor and the backlight simultaneously under the protective layer, the backlight is disposed at a side of the optical fingerprint sensor, and an optical pad upper layer is disposed between the optical fingerprint sensor and the protective layer, thereby The distance between the optical fingerprint sensor and the protective layer is increased, and the width of the optical fingerprint sensor receiving light region is enlarged, thereby improving the quality of the fingerprint image collected by the optical fingerprint sensor module. More importantly, due to the presence of the upper layer of the optical pad, the light of the backlight is adjusted by the upper layer of the optical pad before entering the protective layer. Therefore, the incident angle of the corresponding light on the upper surface of the protective layer can be increased, and accordingly, the corresponding incident light is protected. Total reflection occurs in the interface between the upper surface of the layer and the air, and the interface where the finger fingerprint contacts the upper surface of the protective layer normally performs optical phenomena such as reflection and refraction. At this time, different positions of the finger fingerprint image (ie, valley position and The ridge position) contrast is significantly improved and the quality of the fingerprint image is improved.

DRAWINGS

1 is a schematic structural view of an optical fingerprint sensor module;

2 is a schematic top plan view of an optical fingerprint sensor module according to a first embodiment of the present invention;

3 is a cross-sectional structural view of an optical fingerprint sensor module according to a first embodiment of the present invention;

4 is a cross-sectional structural view of an optical fingerprint sensor module according to a second embodiment of the present invention;

5 is a cross-sectional structural view of an optical fingerprint sensor module according to a third embodiment of the present invention;

6 is a cross-sectional structural view of an optical fingerprint sensor module according to a fourth embodiment of the present invention;

FIG. 7 is a cross-sectional structural diagram of an optical fingerprint sensor module according to a fifth embodiment of the present invention.

detailed description

An optical fingerprint sensor module, as shown in FIG. 1, includes a protective layer 100, an optical fingerprint sensor 110, and a backlight 120. The backlight 120 is located under the protective layer 100, and the optical fingerprint sensor 110 is directly contacted and laminated under the protective layer 100. The backlight 120 is located on the side of the optical fingerprint sensor 110. At this time, the incident angle a of the light emitted from the backlight 120 into the protective layer 100 is small. Therefore, the width A of the region where the optical fingerprint sensor 110 can receive the reflected light is small, and most of the optical fingerprint sensor 110 cannot be used. Fingerprint image acquisition, so the performance of the optical fingerprint sensor module shown in Figure 1 needs to be improved, and the quality of the fingerprint image collected by the optical fingerprint sensor module shown in Figure 1 needs to be improved.

More importantly, in order to acquire a higher quality fingerprint image, it is generally desirable to be able to have a first interface between the upper surface of the protective layer 100 and the air when the incident light reaches the upper surface of the protective layer 100 (the fingerprint valley position and the upper surface of the protective layer 100). There is air between them, total reflection occurs, and the second interface of the upper surface of the protective layer 100 and the fingerprint contact position (the fingerprint ridge position can be in contact with the upper surface of the protective layer) is normally refracted and reflected (ie, no total reflection occurs), Thereby improving the contrast of different positions of the fingerprint (valley position and ridge position) and improving the quality of the fingerprint image. The fingerprint sensor module shown in FIG. 1 cannot achieve total reflection of the first interface and no total reflection of the second interface. Therefore, the optical fingerprint sensor module shown in FIG. 1 cannot improve the fingerprint image quality.

To this end, the present invention provides an optical fingerprint sensor module in which an optical fingerprint sensor and a backlight are simultaneously disposed under a protective layer, the backlight is disposed at a side of the optical fingerprint sensor, and between the optical fingerprint sensor and the protective layer The upper layer of the optical pad is arranged to increase the distance between the optical fingerprint sensor and the protective layer, and expand the width of the light receiving area of the optical fingerprint sensor, thereby improving the quality of the fingerprint image collected by the optical fingerprint sensor module.

The above described objects, features, and advantages of the present invention will be more apparent from the aspects of the invention.

The first embodiment of the present invention provides an optical fingerprint sensor module. Please refer to FIG. 2 and FIG. 3 in combination. 2 is a schematic top plan view of the optical fingerprint sensor module. 3 is a schematic cross-sectional view of the optical fingerprint sensor module. FIG. 3 can be regarded as a schematic cross-sectional view taken along line DD of FIG. 2 . The optical fingerprint sensor module includes a protective layer 200, an optical fingerprint sensor 210, and a backlight 220. The backlight 220 is located below the protective layer 200, and the optical fingerprint sensor 210 is located below the protective layer 200. The backlight 220 is located on the side of the optical fingerprint sensor 210. There is also an optical pad high layer 230 between the optical fingerprint sensor 210 and the protective layer 200.

It should be noted that, in FIG. 2, the optical pad high layer 230 and the backlight 220 are shown as dashed lines because they are actually covered by the protective layer 200, and thus are indicated by broken lines. It should be noted that, in other embodiments, the protective layer 200 may not cover the backlight 220 in a plan view direction. Moreover, in FIG. 2, the optical pad high layer 230 and the optical fingerprint sensor 210 have the same shape and area in plan view, and therefore, the optical pad high layer 230 completely covers the optical fingerprint sensor 210. In other embodiments, the planar shape and area of the optical pad high layer 230 and the fingerprint sensor 210 may not be identical. For example, the planar area of the optical pad high layer 230 may be larger than the plan view area of the optical fingerprint sensor 210.

In this embodiment, the light emitted by the backlight 220 enters the protective layer 200 from the upper layer 230 of the optical pad. Specifically, the light emitted by the backlight 220 enters the upper layer 230 of the optical pad from the side of the upper layer 230 of the optical pad, and then enters the protective layer 200 from the upper layer 230 of the optical pad, and optical phenomena such as reflection and refraction occur on the upper surface of the protective layer 200, and the reflection Light through the protective layer After 200, it returns to the upper layer 230 of the optical pad, and then enters the optical fingerprint sensor 210 from the upper layer 230 of the optical pad.

In order to allow the light emitted by the backlight 220 to enter the protective layer 200 from the upper layer 230 of the optical pad (that is, the light entering the protective layer 200 must first pass through the upper layer 230 of the optical pad), instead of entering the protective layer 200 without passing through the upper layer 230 of the optical pad. In this embodiment, two aspects can be used: on the one hand, the light range of the light emitted by the backlight 220 can be adjusted, so that the light illuminates only the side of the upper layer 230 of the optical pad; on the other hand, as shown in FIG. In the lower surface of the protective layer 200, the light-shielding layer 240 (shown in FIG. 3) is applied to the area where the light from the backlight 220 is irradiated, thereby preventing the light from entering the protective layer 200 without passing through the upper layer 230 of the optical pad.

In this embodiment, the light entering the protective layer 200 must first pass through the upper layer 230 of the optical pad to avoid the light entering the protective layer 200 without passing through the upper layer 230 of the optical pad, thereby preventing the light from being reflected at a different angle from other rays. The position is illuminated to the optical fingerprint sensor 210, causing the fingerprint image to become blurred.

In this embodiment, the backlight 220 is located on the left side of the optical fingerprint sensor 210 and is located on the lower left side. In other embodiments, the backlight 220 may also be located on the other side of the optical fingerprint sensor 210 and below the side (beveled downward).

The backlight 220 is located below the side of the optical fingerprint sensor 210, meaning that the backlight 220 is not located directly below the optical fingerprint sensor 210. Directly below the optical fingerprint sensor 210 is a portion that the optical fingerprint sensor 210 can cover when viewed from a top down direction. Since the backlight 220 is located below the side of the optical fingerprint sensor 210 rather than directly below, the backlight 220 and the optical fingerprint sensor 210 can be seen simultaneously in FIG. 2, and the two do not overlap. At this time, the backlight 220 may not include a structure such as a light guide plate.

2 and FIG. 3, when the backlight 220 is located under the side of the optical fingerprint sensor 210, the light emitted by the backlight 220 can pass through the optical fingerprint sensor 210 (or other structure that blocks light), but through the air. Or the vacuum reaches the side of the upper layer 230 of the optical pad, thereby facilitating the reduction of the volume of the optical fingerprint sensor module, and facilitating the application of more light from the backlight 220 to the fingerprint image collection, which is beneficial to obtain better. Fingerprint image.

In this embodiment, the optical fingerprint sensor 210, the optical pad high layer 230 and the protective layer 200 are directly stacked. The "direct lamination" means that the optical fingerprint sensor 210 and the optical pad high layer 230 are at least partially in contact with each other, the optical pad high layer 230 and the protective layer 200. There is at least partial contact between them, and when all three are flat substrates, they may just be in a stacked form as shown in FIG.

In other embodiments, the upper layer of the optical pad may be directly pasted with the protective layer, or the upper layer of the optical pad may be directly pasted with the optical fingerprint sensor and the protective layer. When "directly pasting", the protective layer, the upper layer of the optical pad, and the optical fingerprint sensor may be laminated and bonded by a glue layer. The adhesive layer may be an optical adhesive layer, and the material of the optical adhesive layer may specifically be a thermal optical adhesive layer, a photosensitive optical adhesive layer or an optical double-sided adhesive tape. In other embodiments, the sides of the upper layer 230 of the optical pad may have a light anti-reflective layer (not shown) such that more light can enter the upper layer 230 of the optical pad from the side of the upper layer 230 of the optical pad.

In this embodiment, the backlight 220 and the upper layer 230 of the optical pad may have a space (not labeled). The presence of the spacing ensures that there is no direct contact between the backlight 220 and the optical pad high layer 230. The specific size of the interval can be determined according to design needs. For example, in one example, the spacing may be greater than or equal to the width of the backlight 220. In other embodiments, there may be no space between the backlight 220 and the upper layer 230 of the optical pad, that is, the backlight 220 is in direct contact with the upper layer 230 of the optical pad. In this case, it is necessary to ensure that all or most of the light emitted by the backlight 220 is obliquely upward. The light may have a small amount of light emitted in a horizontal direction, but the light emitted obliquely downward is prevented from being irradiated to the optical fingerprint sensor 210 without passing through the protective layer 200.

In this embodiment, the backlight 220 is a point light source, such as an LED light. The light of the LED lamp may be near ultraviolet light, purple light, blue light, green light, yellow light, red light, near infrared light or white light.

In this embodiment, the protective layer 200 is a single layer structure, that is, the protective layer 200 can be a substrate, as shown in FIG. In other embodiments, the protective layer 200 may also have a multilayer structure.

2 and 3, although not shown, in other embodiments, at least one of the upper surface, the lower surface of the protective layer 200, and the upper surface of the optical fingerprint sensor 210 may have a filter layer. The filter layer can be used to filter ambient light or to change the apparent color of the protective layer 200 or optical fingerprint sensor 210.

In this embodiment, the optical fingerprint sensor 210 may be an image sensor fabricated by a CMOS process based on a silicon wafer, or may be an image sensor fabricated by a TFT process based on a glass substrate.

In the optical fingerprint sensor module provided in this embodiment, by placing the optical fingerprint sensor 210 and the backlight 220 under the protective layer 200 at the same time, the backlight 220 is disposed at the side of the optical fingerprint sensor 210, and is in the optical fingerprint sensor. An optical pad high layer 230 is disposed between the 210 and the protective layer 200 to increase the distance between the optical fingerprint sensor 210 and the protective layer 200, and expand the width of the optical fingerprint sensor 210 to receive the light region (the optical fingerprint sensor 210 receives the width of the light region) For the width B, comparing FIG. 1 and FIG. 3, it can be seen that the width B is much larger than the width A), thereby improving the quality of the fingerprint image collected by the optical fingerprint sensor module.

In this embodiment, when the light emitted by the backlight 220 passes through the upper layer 230 of the optical pad and then enters the protective layer 200, the angle between the corresponding light and the area on the upper surface of the protective layer 200 for contacting the fingerprint is an acute angle. At this time, the light emitted by the backlight 220 can be reflected and refracted at the interface between the upper surface of the protective layer 200 and the finger fingerprint according to a corresponding offset amount (the offset amount refers to the horizontal offset distance in FIG. 3). And causing most of the effective reflected light to illuminate the photosensitive area of the optical fingerprint sensor 210 (specifically irradiated into the photosensitive pixels at substantially the same offset distance from the corresponding reflection point), therefore, the entire optical fingerprint sensor module does not need a light guide plate With a structure such as a condenser lens, fingerprint image recognition can be realized, a clear fingerprint image is formed, and the structure is simplified, and the cost is reduced.

More importantly, due to the existence of the upper layer 230 of the optical pad, according to the geometrical optical principle, in FIG. 3, the light of the backlight 220 is adjusted by the upper layer 230 of the optical pad before entering the protective layer 200. Therefore, the corresponding light is on the protective layer 200. The incident angle of the surface can be increased, and accordingly, the corresponding incident light is more likely to be on the interface between the upper surface of the protective layer 200 and the air. Total reflection occurs in the middle, and the interface where the finger fingerprint contacts the upper surface of the protective layer 200 normally performs optical phenomena such as reflection and refraction. At this time, the contrast of different positions (ie, valley position and ridge position) of the finger fingerprint image is obvious. Improved, improved fingerprint image quality.

In this embodiment, in order to better cause different refraction and reflection phenomena at the different positions described above, the refractive index of the upper layer 230 of the optical pad may be selected to be 1.2 or more.

A second embodiment of the present invention provides another optical fingerprint sensor module. Please refer to FIG. 4. 4 is a schematic cross-sectional view of the optical fingerprint sensor module. The optical fingerprint sensor module includes a protective layer 300, an optical fingerprint sensor 310, and a backlight (not labeled). The upper surface of the protective layer 300 is used for finger contact pressing. The optical fingerprint sensor 310 is located below the protective layer 300, the backlight is also located below the protective layer 300, and the backlight is located at the side of the optical fingerprint sensor 310. At the same time, the optical fingerprint sensor 310 and the protective layer 300 have an optical pad high layer 340, and the protective layer 300, the optical pad high layer 340 and the optical fingerprint sensor 310 are directly stacked.

Referring back to FIG. 3, since the emitted light of the point source of the LED has a certain divergence angle, when only one LED lamp is used as the backlight (refer to the corresponding content of the foregoing embodiment), the emitted light and the reflected light of the backlight are parallel to each other. The light difference is large. That is to say, the angles of the light irradiated to the upper surface of the protective layer may be greatly different, and finally the reflected light of the different reflecting points is incident on the photosensitive pixels of the optical fingerprint sensor at different deviation distances, so that the fingerprint image may be distorted.

In order to solve the above-mentioned fingerprint image distortion problem, in the embodiment, the backlight includes four LED lights. Due to the planar display, only two of the LED lights are shown in the cross section shown in FIG. 4, which are LED lights 320 respectively. And LED lights 330. The four LED lamps are evenly distributed under the protective layer while being evenly distributed on the side of the optical fingerprint sensor 310, or four lamps are evenly distributed at the four corners of the optical fingerprint sensor 310. At this time, although the light emitted by the four LED lamps may each be non-parallel light, the image distortion of the non-parallel light can be corrected by using the four LED lamps at the same time. Specifically, the four LED lights can adopt the method of taking pictures in turn (the four pictures of the rotating pictures are taken separately according to the time series), and then the image processing is used to correct the distortion and improve the fingerprint image. Quality, improve fingerprint recognition accuracy.

In other embodiments, when the top view pattern of the optical fingerprint sensor 310 is a regular polygon, in order to make the plurality of LED lamps evenly distributed under the protective layer, the corresponding plurality of LED lamps may be optical fingerprint sensor 310 in a plan view direction. The center of the top view pattern is a symmetrical point, which is symmetrically or axially symmetric, and is evenly distributed around the optical fingerprint sensor 310. When evenly distributed, the spacing between adjacent LED lamps can be made equal.

In this embodiment, the light of the LED lamp may be near ultraviolet light, purple light, blue light, green light, yellow light, red light, near infrared light or white light.

In other embodiments, the backlight may also include two LED lamps, the two LED lamps being evenly distributed below the protective layer. For example, one of the LED lights is located on the left side of the optical fingerprint sensor 310, and the other LED light is located on the right side of the optical fingerprint sensor 310, and is also taken in turn. In other embodiments, the backlight may include more than three LED lamps, and more than three LED lamps are evenly distributed under the protective layer, and are also taken in turn.

For more details on the structure and advantages of the optical fingerprint sensor module provided in this embodiment, reference may be made to the corresponding content of the foregoing embodiments.

A third embodiment of the present invention provides another optical fingerprint sensor module. Please refer to FIG. 5. FIG. 5 is a schematic cross-sectional view of the optical fingerprint sensor module. The optical fingerprint sensor module includes a protective layer 400, an optical fingerprint sensor 410, and a backlight 420. The upper surface of the protective layer 400 is used for contact pressing of the finger 430. The backlight 420 is located below the protective layer 400 and the optical fingerprint sensor 410 is located below the protective layer 400. The backlight 420 is located on the side of the optical fingerprint sensor 410. The protective layer 400 and the optical fingerprint sensor 410 have an optical pad high layer 430, and the protective layer 400, the optical pad high layer 430 and the optical fingerprint sensor 410 are directly stacked.

In this embodiment, the upper surface of the optical pad 430 is configured to receive a light-transmitting layer 440 on the side of the backlight, and the light-reflecting layer 440 can increase the proportion of the light of the backlight into the upper layer 430 of the optical pad.

More structures and advantages of the optical fingerprint sensor module provided by this embodiment can be Reference is made to the corresponding content of the foregoing embodiment.

A fourth embodiment of the present invention provides another optical fingerprint sensor module. Please refer to FIG. 6. 6 is a schematic cross-sectional view of the optical fingerprint sensor module. The optical fingerprint sensor module includes a protective layer 500, an optical fingerprint sensor 510, and a backlight 520. The upper surface of the protective layer 500 is used for finger contact pressing. The backlight 520 is located below the protective layer 500 and the optical fingerprint sensor 510 is located below the protective layer 500. The backlight 520 is located on the side of the optical fingerprint sensor 510. The optical fingerprint sensor 510 and the protective layer 500 have an optical pad high layer 530, and the protective layer 500, the optical pad high layer 530 and the optical fingerprint sensor 510 are directly pasted together (the three are pasted by a glue layer, and the glue layer is not display).

In this embodiment, the light-emitting surface of the backlight 520 has a collecting lens 540, and the collecting lens 540 can convert the light of the backlight 520 into parallel light or near-parallel light (the difference in angle between the near-parallel light rays) Less than 10 degrees), the light of the backlight 520 first enters the collecting lens 540 and then enters the upper layer 530 of the optical pad. That is, the condensing lens 540 is added to make the incident light parallel or nearly parallel, thereby solving the problem of fingerprint image distortion.

A fifth embodiment of the present invention provides another optical fingerprint sensor module. Please refer to FIG. 7. 7 is a schematic cross-sectional view of the optical fingerprint sensor module. The optical fingerprint sensor module includes a protective layer 600, an optical fingerprint sensor 610, and a backlight 620. The upper surface of the protective layer 600 is used for finger contact pressing. The backlight 620 is located below the protective layer 600 and the optical fingerprint sensor 610 is located below the protective layer 600. The backlight 620 is located on the side of the optical fingerprint sensor 610. There is also an optical pad high layer 630 between the optical fingerprint sensor 610 and the protective layer 600. The optical fingerprint sensor 610, the optical pad high layer 630 and the protective layer 600 are directly stacked from bottom to top.

In this embodiment, the side surface of the upper layer 630 of the optical pad is a condensing surface, and the condensing surface converts the light emitted by the backlight into parallel light or near-parallel light, thereby improving the image quality of the fingerprint.

In this embodiment, the upper layer 630 of the optical pad may be a glass layer, a plastic layer or an optical adhesive layer, and the refractive index of the upper layer 630 of the optical pad may be adjusted to be 1.2 or more, so that the optical pad upper layer 630 can better improve the optical fingerprint sensor module. The quality of the captured fingerprint image.

In this embodiment, the concentrating surface may be a sloped surface, a spherical crown surface, an ellipsoidal crown surface, a conical side surface or a pyramid side surface.

It should be noted that, in other embodiments, the side surface of the upper layer 630 of the optical pad may further have a light anti-reflection layer (not shown), which can increase the light of the backlight 620 into the upper layer 630 of the optical pad. The ratio, thereby increasing the fingerprint image signal value.

Although the present invention has been disclosed above, the present invention is not limited thereto. Any changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be determined by the scope defined by the appended claims.

Claims

An optical fingerprint sensor module includes:

The protective layer;

An optical fingerprint sensor, the optical fingerprint sensor being located below the protective layer;

a backlight, the backlight being located below the protective layer;

It is characterized in that

The backlight is located at a side of the optical fingerprint sensor;

The optical fingerprint sensor and the protective layer further have an upper layer of an optical pad;

Light emitted by the backlight enters the protective layer from a high level of the optical pad.
The optical fingerprint sensor module according to claim 1, wherein said optical pad upper layer is directly laminated with said optical fingerprint sensor and said protective layer, or said optical pad upper layer and said optical fingerprint sensor and said The protective layer is directly pasted.
The optical fingerprint sensor module of claim 1 , wherein the light emitted by the backlight enters the upper layer of the optical pad from the side of the upper layer of the optical pad, and then enters the protection from the upper layer of the optical pad. a layer, and a partial reflection on the upper surface of the protective layer, the reflected light passes through the protective layer and then returns to the upper layer of the optical pad, and then enters the optical fingerprint sensor from the upper layer of the optical pad.
The optical fingerprint sensor module according to claim 3, wherein the refractive index of the upper layer of the optical pad is 1.2 or more.
The optical fingerprint sensor module according to claim 1, wherein the protective layer is a single layer or a multilayer structure, and the upper surface and the lower surface of the protective layer, the upper surface and the lower surface of the upper surface of the optical pad And at least one of the surfaces of the upper surface of the optical fingerprint sensor has a filter layer.
The optical fingerprint sensor module according to any one of claims 1 to 5, wherein the backlight comprises at least one LED lamp, and the light of the LED lamp is near ultraviolet light, purple light, blue light, green light. Light, yellow, red, near-infrared, or white.
The optical fingerprint sensor module according to any one of claims 1 to 5, wherein the backlight comprises two or more LED lamps, and the two or more LED lamps are evenly distributed Below the protective layer, the light of the LED lamp is near ultraviolet light, purple light, blue light, green light, yellow light, red light, near infrared light or white light.
The optical fingerprint sensor module according to any one of claims 1 to 5, wherein a front surface of the light source of the backlight has a collecting lens, and the collecting lens can convert the light of the backlight into Parallel light or near-parallel light, the light of the backlight first enters the collecting lens and then enters the side of the upper layer of the optical pad.
An optical fingerprint sensor module according to any one of claims 1 to 5, The side surface of the upper layer of the optical pad is a condensing surface, and the condensing surface converts light emitted by the backlight into parallel light or near-parallel light.
The optical fingerprint sensor module of claim 9 , wherein the upper surface of the optical pad is configured to receive a light-emitting layer on a side of the backlight, and the light-enhancing layer can increase the backlight. The proportion of light entering the upper layer of the optical pad.
The optical fingerprint sensor module according to claim 10, wherein the concentrating surface is a sloped surface, a spherical crown surface, an ellipsoidal crown surface, a conical side surface or a pyramid side surface.
The optical fingerprint sensor module according to claim 11, wherein the concentrating surface has a light antireflection layer, and the light permeable layer can increase the proportion of light of the backlight into the transparent medium. .
The optical fingerprint sensor module according to any one of claims 1 to 5, wherein the upper surface of the optical pad is configured to receive a light-transmitting layer on a side surface of the backlight, and the light-enhancing layer can be increased. The proportion of light from the backlight entering the upper layer of the optical pad.