CN210155697U

CN210155697U - Prism membrane module and optical fingerprint identification device under screen

Info

Publication number: CN210155697U
Application number: CN201921460746.5U
Authority: CN
Inventors: 张胜斌; 葛丛
Original assignee: Shenzhen Goodix Technology Co Ltd
Current assignee: Wuhu Zhongpu Intelligent Equipment Co ltd
Priority date: 2019-09-04
Filing date: 2019-09-04
Publication date: 2020-03-17
Anticipated expiration: 2029-09-04

Abstract

The utility model provides an optical fingerprint identification device under prism membrane module and screen. The utility model provides a prism membrane module is applicable to the liquid crystal display who supports fingerprint identification function under the screen, the prism membrane module is arranged in liquid crystal display's backlight unit, and liquid crystal display's display area includes that the fingerprint identification is regional, the prism membrane module includes one deck prism membrane at least, the first surface of prism membrane is provided with the prism structure, the prism structure includes a plurality of prisms, and the first surface has the correction region who corresponds with the fingerprint identification region, the prism in the correction region has the condensing surface, angle between condensing surface and the prism membrane is less than the angle between the prism face of the outer prism of correction region and the prism membrane. The utility model discloses a prism membrane module is less to fingerprint signal's influence, can make the fingerprint image have better definition.

Description

Prism membrane module and optical fingerprint identification device under screen

Technical Field

The utility model relates to a liquid crystal display technology field especially relates to an optical fingerprint identification device under prism membrane module and screen.

Background

Currently, Display screens are mainly classified into Liquid Crystal Display (LCD) screens and Organic Light-Emitting Diode (OLED) screens, wherein the LCD screens mainly include a Liquid Crystal panel and a backlight source, a prism film is usually disposed in the backlight source, the prism film is located between a diffusion sheet and the Liquid Crystal panel, and the prism film is mainly used for converging Light emitted from the diffusion sheet and uniformly diffused to various angles to axial angles, that is, to a front view angle of the Liquid Crystal panel, and improving axial brightness without increasing total emergent Light flux.

In the backlight source, two layers of stacked prism films can be generally arranged, one layer of prism film with the prism direction perpendicular to the prism film is stacked on the other layer of prism film, and after the light source passes through the two prism films which are vertically arranged, light can be converged in the two perpendicular directions, so that the total gain of the prism films can be increased, and the light efficiency of the backlight source can be enhanced.

However, for the identification of the fingerprint under the screen, when the light reflected by the fingerprint image on the screen passes through the double-layer prism film, the same characteristic point refracts signal points in four directions, and the refracted signals are blurred due to mutual coincidence, so that the definition of the fingerprint image is influenced, and effective fingerprint information cannot be acquired.

SUMMERY OF THE UTILITY MODEL

The utility model provides an optical fingerprint identification device under prism membrane module and screen, prism membrane module are less to fingerprint signal's influence, can make fingerprint image have better definition.

On the one hand, the utility model provides a prism membrane module, be applicable to the liquid crystal display who supports fingerprint identification function under the screen, the prism membrane module is located liquid crystal display's backlight unit, and liquid crystal display's display area includes that fingerprint identification is regional, the prism membrane module includes one deck prism membrane at least, the first surface of prism membrane is provided with the prism structure, the prism structure includes a plurality of prisms, and the first surface has the correction region that corresponds with the fingerprint identification region, the prism in the correction region has the condensing surface, angle between condensing surface and the prism membrane is less than the angle between the prism surface of the outer prism of correction region and the prism membrane.

In one possible embodiment, the light collection surface is a surface of the prism other than the prism surface of the prism.

In one possible embodiment, the light collection surface is located on top of the prism and connects two oppositely disposed prism faces of the prism.

In one possible embodiment, the height of the light-condensing surface gradually decreases from both sides of the correction region to the center of the correction region.

In one possible embodiment, the light-collecting surface is located between two adjacent prisms, and the light-collecting surface connects the two adjacent prisms.

In one possible embodiment, the height of the light-condensing surface gradually increases from both sides of the correction region to the center of the correction region.

In one possible embodiment, the top of the prism is provided with a light-gathering surface, and the light-gathering surface is connected with two oppositely arranged prism surfaces of the prism; and a light-gathering surface is arranged between two adjacent prisms and is connected with the two adjacent prisms.

In one possible embodiment, the height of the light-condensing surface at the top of the prism gradually decreases from the two sides of the correction area to the center of the correction area, and the height of the light-condensing surface between two adjacent prisms gradually increases from the two sides of the correction area to the center of the correction area.

In one possible embodiment, the light-condensing surface is parallel to the prism film, and the distance from the light-condensing surface to the prism film changes in a gradient manner from the two sides of the correction area to the center of the correction area.

In one possible embodiment, the cross-sectional width of the light-condensing surface gradually increases from both sides of the modified region to the center of the modified region.

In one possible embodiment, the light condensing surfaces from both sides of the correction region to the center of the correction region are located on the first arc surface of the convex prism film.

In a possible embodiment, the center of the first arc surface is located at the center of the correction area, and the first arc surface is symmetrical.

In one possible embodiment, the light-condensing surfaces from both sides of the correction area to the center of the correction area are located on the second circular arc surface convex to the top of the prism.

In a possible embodiment, the center of the second arc surface is located at the center of the correction area, and the second arc surface is symmetrical.

In one possible embodiment, the light condensing surfaces from both sides of the correction region to the center of the correction region are located on the third circular arc surface convex to the prism film and on the fourth circular arc surface convex to the top of the prism.

In a possible embodiment, the centers of the third arc surface and the fourth arc surface are located at the center of the correction area, and the third arc surface and the fourth arc surface are symmetrical.

In one possible embodiment, the light collection surface is a prism surface of a prism.

In one possible embodiment, the prisms are symmetrical to each other about a center of the correction area, and the prism has a first prism face close to the center and a second prism face far from the center, and the light-condensing face is one of the first prism face and the second prism face.

In one possible embodiment, a first included angle is formed between the light-condensing surface and the prism film, and the angle of the first included angle gradually decreases from two sides of the correction area to the center of the correction area.

In one possible embodiment, a second included angle is formed between the non-light-condensing surface of the first prism surface and the second prism surface and the prism film, and the angle of the second included angle is fixed.

In one possible embodiment, the first included angle is in the range of 0 ° to 45 ° and the second included angle is 45 °.

In a possible embodiment, the gradient of the angular decrease of the first angle ranges from 1 to 3 ° from the sides of the correction zone to the center of the correction zone.

In one possible embodiment, the prism film assembly includes a first prism film and a second prism film which are sequentially stacked, and prism directions of prism structures of the first prism film and the second prism film are perpendicular to each other; the first prism film is close to the liquid crystal panel relative to the second prism film, and the correction area is located on at least one of the first prism film and the second prism film.

In one possible embodiment, the modified region is located on the first prism film.

On the other hand, the utility model provides an optical fingerprint identification device under screen, including liquid crystal display and the optical fingerprint sensor that has liquid crystal display panel and backlight unit, backlight unit and optical fingerprint sensor set gradually in the liquid crystal display panel below, wherein, backlight unit includes as above the prism membrane module.

The utility model provides an optical fingerprint identification device under prism membrane module and screen, prism membrane module are applicable to the liquid crystal display who supports fingerprint identification function under the screen, have the fingerprint identification region in this liquid crystal display's the display area, and the prism membrane module is arranged in liquid crystal display's backlight unit for improve the angular distribution of light, improve liquid crystal display's luminance. The prism film assembly comprises at least one layer of prism film, the first surface of the prism film is provided with a prism structure, the prism structure comprises a plurality of prisms which are uniformly distributed on the first surface, and light emitted by the backlight source is converged by the prism surface of the prism to improve the brightness; the correction area is arranged on the first surface of the prism film, the correction area corresponds to the fingerprint identification area on the liquid crystal display screen, the prism in the correction area is provided with the light-gathering surface, the included angle between the light-gathering surface and the prism surface is smaller than the included angle between the prism surface of the prism outside the correction area and the prism film, when light reflected by a fingerprint image on the screen passes through the light-gathering surface, the light-gathering surface can generate refracted light rays towards the center of the correction area or directly transmit the light rays without refraction, so that the light rays have better convergence effect, the influence of the prism film on a fingerprint signal is smaller, the signal is dispersed to a smaller extent or does not disperse, a fingerprint image with better definition can be formed, and effective identification of fingerprints under the screen of the liquid crystal display screen is realized.

Drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, a brief description will be given below of the drawings required for the description of the embodiments or the prior art, and it is obvious that the drawings in the following description are some embodiments of the present invention. For a person skilled in the art, without inventive effort, further figures can be obtained from these figures.

Fig. 1 is a schematic structural diagram of a prism film assembly according to an embodiment of the present invention;

FIG. 2 is a schematic view of the prismatic film assembly of FIG. 1 from another perspective;

fig. 3 is a schematic structural diagram of a prism film according to an embodiment of the present invention;

fig. 4 is a schematic cross-sectional view of a prism film according to an embodiment of the present invention;

fig. 5 is a schematic cross-sectional view of a second prism film according to an embodiment of the present invention;

fig. 6 is a schematic cross-sectional view of a third prism film according to an embodiment of the present invention;

fig. 7 is a schematic cross-sectional view of a fourth prism film according to an embodiment of the present invention;

fig. 8 is a schematic cross-sectional view of a fifth prism film according to an embodiment of the present invention;

fig. 9 is a schematic cross-sectional view of a sixth prism film according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of a seventh prism film according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of an eighth prism film according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of an optical fingerprint identification device under a screen according to an embodiment of the present invention.

Description of reference numerals:

1-a prism film assembly; 11-a prismatic film; 12-a first prismatic film; 13-a second prismatic film; 14-a prismatic structure; 15-a prism; 151-light-gathering surface; 152-prism facets; 153-a first prism face; 154-a second prism face; 16-a correction area; 161-a first arc surface; 162-a second arc surface; 163-third arc surface; 164-a fourth arc surface; 17-a first included angle; 18-second angle; 10-a liquid crystal panel; 20-a backlight module; 21-a diffusion sheet; 30-an optical fingerprint sensor; 100-optical fingerprint recognition device under the screen.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

Example one

With the coming of the full screen age of mobile phones, the application of the fingerprint under the screen is more and more extensive, wherein the optical fingerprint under the screen is the most popular. Wherein, fingerprint identification under the optical screen to the LCD screen usually sets up optics fingerprint sensor through the below at backlight unit, is provided with the fingerprint identification region on the LCD screen, when carrying out fingerprint identification, and the backlight or the fingerprint detection light that is used for fingerprint identification see through the screen and illuminate the fingerprint on the screen, and the fingerprint image of reflection shines to optics fingerprint sensor through backlight unit, is discerned fingerprint image by optics fingerprint sensor.

The backlight module of the LCD screen generally comprises a prism film, the prism film is arranged between a diffusion sheet and a liquid crystal panel in the backlight module, the diffusion sheet can uniformly diffuse light rays emitted by a backlight source to all directions so that the light rays can uniformly irradiate all parts of the liquid crystal panel, the prism film is used for improving the angular distribution of the light rays, and the prism film can converge light emitted from the diffusion sheet and uniformly diffused to all angles to an axial angle, namely the front view angle of the liquid crystal panel, so that the axial brightness is improved under the condition of not increasing the total emergent luminous flux, and the screen brightness is improved.

But for optical fingerprint identification under the screen of LCD screen, the light that fingerprint image on the screen reflects to the prism membrane can be dispersed because of the refraction and reflection of prism membrane, and to backlight unit including the structure of one deck prism membrane, the same characteristic point of fingerprint image can refract two direction signal points out after the single-deck prism membrane, and to backlight unit including the structure of two-layer overlapping and prism direction vertically prism membrane, the same characteristic point of fingerprint image can refract out four direction signal points out after the double prism membrane. Can influence fingerprint image's definition like this, and can be with fingerprint image segmentation for two parts or four parts, coincide each other between the fingerprint signal of refracting out to can make the fingerprint signal fuzzy, cause the unable effective fingerprint signal of gathering of optical fingerprint sensor.

In view of this, the present embodiment provides a prism film assembly to improve the dispersion phenomenon of the prism film on the fingerprint signal, reduce the influence of the prism film on the fingerprint signal, and improve the definition of the fingerprint image, thereby implementing effective identification of the fingerprint under the LCD screen.

Fig. 1 is a schematic structural diagram of a prism film assembly according to an embodiment of the present invention; FIG. 2 is a schematic view of the prismatic film assembly of FIG. 1 from another perspective; fig. 3 is a schematic structural diagram of a prism film according to an embodiment of the present invention.

Fig. 4 is a schematic cross-sectional view of a prism film according to an embodiment of the present invention; fig. 5 is a schematic cross-sectional view of a second prism film according to an embodiment of the present invention; fig. 6 is a schematic cross-sectional view of a third prism film according to an embodiment of the present invention; fig. 7 is a schematic cross-sectional view of a fourth prism film according to an embodiment of the present invention; fig. 8 is a schematic cross-sectional view of a fifth prism film according to an embodiment of the present invention; fig. 9 is a schematic cross-sectional view of a sixth prism film according to an embodiment of the present invention; fig. 10 is a schematic structural diagram of a seventh prism film according to an embodiment of the present invention; fig. 11 is a schematic structural diagram of an eighth prism film according to an embodiment of the present invention.

As shown in fig. 1 to 11, the present embodiment provides a prism film assembly 1, where the prism film assembly 1 is suitable for a liquid crystal display supporting an off-screen fingerprint identification function, the prism film assembly 1 is located in a backlight module of the liquid crystal display, and a display area of the liquid crystal display includes a fingerprint identification area, the prism film assembly 1 includes at least one layer of prism film 11, a first surface of the prism film 11 is provided with a prism structure 14, the prism structure 14 includes a plurality of prisms 15, and the first surface has a correction area 16 corresponding to the fingerprint identification area, the prisms 15 in the correction area 16 have a light-condensing surface 151, and an angle between the light-condensing surface 151 and the prism film 11 is smaller than an angle between a prism surface 152 of the prism 15 outside the correction area 16 and the prism film 11.

As shown in fig. 1 to fig. 3, the prism film assembly 1 provided in this embodiment is located in a backlight module of a liquid crystal display, the liquid crystal display supports a fingerprint identification function under the liquid crystal display, and a display area of the liquid crystal display has a fingerprint identification area, as described above, the prism film assembly 1 may be disposed between a diffusion sheet and a liquid crystal panel, and details are not repeated here. The prism film assembly 1 comprises at least one layer of prism film 11, the first surface of the prism film 11 is provided with a prism structure 14, the prism structure 14 is a plurality of prisms 15 uniformly arranged on the first surface, the prisms 15 can be in a triangular cone shape, the bottom edge of the prisms 15 is connected to the prism film 11, the two side edges are prism surfaces 152, light rays emitted by the diffusion sheet are projected into the prism film 11, and the light rays are converged in the axial direction through the refraction and reflection action of the prism surfaces 152 on the two sides of the prisms 15 so as to improve the axial brightness.

As described above, the prism surfaces 152 on both sides of the prism 15 on the first surface of the prism film 11 have a converging effect on the light emitted from the diffusion sheet, and the light emitted to the liquid crystal panel can be converged in the axial direction by the prism 15, so as to improve the brightness of the liquid crystal display panel; however, the prism 15 has an opposite light-dispersing function to the light of the fingerprint image reflected on the liquid crystal panel, and fingerprint signals refracted by the prism 15 overlap with each other, so that the signals are blurred and a clear fingerprint image cannot be formed.

In contrast, in the present embodiment, the first surface of the prism film 11 is provided with the correction area 16, the correction area 16 corresponds to the fingerprint identification area on the liquid crystal panel, the prism 15 in the correction area 16 has the light-condensing surface 151, the light-condensing surface 151 improves the dispersion phenomenon of the prism 15 on the fingerprint signal, and improves the definition of the fingerprint image, and the first surface outside the correction area 16 is the normal prism structure 14.

Specifically, in the correction area 16 of the first surface, the angle between the light-condensing surface 151 of the prism 15 and the prism film 11 is smaller than the angle between the prism surface 152 of the prism 15 and the prism film 11 outside the correction area 16, so that the normal line of the light-condensing surface 151 has a smaller inclination with respect to the normal line of the prism film 11, even the normal line of the light-condensing surface 151 is parallel to the normal line of the prism film 11, i.e., the light-condensing surface 151 is parallel to the prism film 11, so that when the light of the fingerprint image is reflected to the light-condensing surface 151 of the prism 15, the light refracted by the light-condensing surface 151 has a converging effect, so that the refracted light is not dispersed outside the correction area 16 but is converged toward the center of the correction area 16, even the light is transmitted through the light-condensing surface 151 without refraction, so that the dispersion effect of the light reflected by the fingerprint image by the prism film 11 can be reduced, even the light is not dispersed, and the fingerprint image still has, to reduce the influence of the prism film 11 on the fingerprint signal for effective recognition of the fingerprint image.

It should be noted that, in this embodiment, the correction area 16 corresponds to a fingerprint identification area of the liquid crystal panel, and the prism 15 in the correction area 16 has a light-condensing surface 151, so that light reflected by a fingerprint image can still form a relatively clear fingerprint image after being cooled and quiet; but the prisms 15 on the first surface of the prism film 11 outside the correction area 16 remain, so that the light emitted from the diffusion sheet has a better axial convergence effect when passing through the prisms 15, and the prism film 11 is ensured to have a function of improving the axial brightness.

In addition, the size of the correction area 16 may be determined according to the field range, for example, the range may be between + 4 and + 20, and the position of the correction area 16 may be determined according to the actual fingerprint identification areas of different liquid crystal panels, which is not limited in this embodiment. In the area outside the correction area 16 of the first surface of the prism film 11, the angles between the prism surfaces 152 on both sides of the prism 15 and the prism film 11 may be 45 °, so that the light emitted from the diffusion sheet can be better converged in the axial direction, i.e. the front view direction of the liquid crystal panel, after being refracted by the prism surfaces 152.

In order to make the prism film assembly 1 have better axial convergence on the light emitted from the diffusion sheet, in a possible embodiment, the prism film assembly 1 may include a first prism film 12 and a second prism film 13 which are sequentially stacked, and the directions of prisms 15 of the prism structures 14 of the first prism film 12 and the second prism film 13 may be perpendicular to each other; wherein the first prism film 12 is close to the liquid crystal panel relative to the second prism film 13, and the correction region 16 may be located on at least one of the first prism film 12 and the second prism film 13.

As shown in fig. 1 and 2, in the present embodiment, the prism film assembly 1 may include a first prism film 12 and a second prism film 13 which are stacked, first surfaces of the first prism film 12 and the second prism film 13 face the liquid crystal panel, and directions of prisms 15 of prism structures 14 on the first surfaces of the first prism film 12 and the second prism film 13 are perpendicular to each other, so that after light rays emitted from a diffusion sheet sequentially pass through two layers of prism structures 14 with perpendicular directions, the light rays may be converged in two axial directions, thereby increasing the total gain of the prism film assembly 1, and axial brightness may be further improved by the first prism film 12 and the second prism film 13, thereby enhancing brightness of the liquid crystal panel.

Of the first prism film 12 and the second prism film 13, the first prism film 12 is closer to the liquid crystal panel, that is, the light emitted from the diffusion sheet passes through the first prism film 12 and then passes through the second prism film 13, and the light reflected by the fingerprint image on the screen passes through the first prism film 12 and then passes through the second prism film 13.

The correction region 16 may be provided on at least one of the first prism film 12 and the second prism film 13, that is, the correction region 16 may be provided on the first prism film 12, the second prism film 13, or both the first prism film 12 and the second prism film 13. When the correction regions 16 are disposed on both the first prism film 12 and the second prism film 13, the correction regions 16 on the two prism films 11 may overlap with each other, or the positions of the correction regions 16 on the second prism film 13 may be appropriately set according to the optical path of the fingerprint image after passing through the correction region 16 on the first prism film 12, so that the light reflected by the fingerprint image may pass through the correction region 16 on the second prism film 13.

In one particular embodiment, the modified region 16 may be located on the first prismatic film 12, as shown in fig. 3. In this embodiment, the correction area 16 may be at least disposed on the first prism film 12 below the liquid crystal panel, so that when the light reflected by the fingerprint image passes through the correction area 16 of the first prism film 12, the light-condensing surface 151 of the prism 15 may condense the light, thereby reducing the dispersion degree of the fingerprint signal, or making the fingerprint signal not disperse, and a clear fingerprint image may be formed through the correction area 16 of the first prism film 12, so that even if the second prism film 13 is not disposed with the correction area 16, the condensed light passes through the correction area 16

The second prism film 13 does not significantly increase the degree of dispersion, and a clear fingerprint image is still formed.

As shown in fig. 4-9, in one possible embodiment, the light collection surface 151 may be a surface other than the prism surface 152 of the prism 15. Through making prism 15 have condensing surface 151 outside prism face 152, and the contained angle between condensing surface 151 and the prism membrane 11 is less than the contained angle between prism face 152 and the prism membrane 11, compare with prism face 152 like this, when the light of fingerprint image reflection passes through condensing surface 151, the light of condensing surface 151 refraction can assemble to the center of revising the region 16, or light does not take place the refraction when passing through condensing surface 151 but along the straight line transmission, can obtain the less or not fingerprint signal of dispersion degree like this, and then obtain comparatively clear fingerprint image.

In one possible embodiment, the light collection surface 151 may be located on top of the prism 15 and connect the oppositely disposed prism faces 152 of the prism 15, as shown in fig. 4 and 7. In this embodiment, for a normal prism 15, a single prism 15 includes a valley at the top end, and the connection portion between two adjacent prisms 15 is a valley at the bottom end.

By disposing the light-condensing surface 151 on the top of the prism 15, i.e., on the top of the single prism 15, such that the prism 15 is composed of the prism surfaces 152 on both sides and the light-condensing surface 151 on the top connecting the prism surfaces 152 on both sides, the prism surfaces 152 on both sides can maintain the same angle as the prism surfaces 152 outside the correction area 16, and the angle between the light-condensing surface 151 on the top and the prism film 11 is smaller than the angle between the prism surfaces 152 and the prism film 11, such that the light reflected by the fingerprint image is condensed by the light-condensing surface 151 on the top of the prism 15.

Alternatively, the height of the light-condensing surface 151 may gradually decrease from both sides of the modified area 16 to the center of the modified area 16. As shown in fig. 4 and 7, the height of the light-condensing surface 151 gradually decreases from the two sides of the correction area 16 to the center, that is, the light-condensing surfaces 151 located on the two sides of the correction area 16 are closer to the valley peak of the normal prism 15, and the light-condensing surface 151 of the prism 15 gradually approaches the valley bottom along the two sides of the correction area 16 to the center, so that as the height of the light-condensing surface 151 decreases, the position of the light-condensing surface 151 in the prism 15 is closer to the valley bottom, the cross-sectional area of the light-condensing surface 151 increases, and the ratio of the light reflected by the fingerprint image to be irradiated to the light-condensing surface 151.

From the two sides to the center of the correction area 16, as the height of the light-condensing surface 151 decreases, the larger the cross-sectional area of the light-condensing surface 151 is, the smaller the area of the prism surface 152 on the two sides of the light-condensing surface 151 is, so that the more light is irradiated to the light-condensing surface 151, the better the light-condensing effect of the light-condensing surface 151 is; the prism 15 may not include the prism surfaces 152 at both sides up to the center of the correction area 16, but only include the light-condensing surface 151, so that all the light irradiated to the prism 15 is condensed by the light-condensing surface 151, the light is condensed better by the center of the correction area 16, and a clear fingerprint image can be formed.

As shown in fig. 4, in one embodiment, the light-condensing surface 151 may be parallel to the prism film 11, and the distance from the light-condensing surface 151 to the prism film 11 varies in a gradient from both sides of the correction region 16 to the center of the correction region 16. The fingerprint identification area on the liquid crystal panel is usually small, and by making the light-condensing surface 151 parallel to the prism film 11, when the fingerprint image of the fingerprint identification area of the liquid crystal panel is reflected to the prism 15, light enters the light-condensing surface 151 in an almost vertical direction, so that the light-condensing surface 151 can make light converge for small-angle refraction, or does not produce refraction to make light directly vertically penetrate through.

In addition, the cross-sectional width of the light condensing surface 151 may gradually increase from both sides of the modified region 16 to the center of the modified region 16. Because the distance from the light-gathering surface 151 to the prism film 11 is changed in a gradient manner from the two sides of the correction area 16 to the center, the width of the cross section of the light-gathering surface 151 is gradually increased, namely, the cross section area of the light-gathering surface 151 is gradually increased, the proportion of the prisms 15 occupied by the light-gathering surface 151 is gradually increased, the area of the prism surface 152 is gradually reduced, the dispersion effect of the prism surface 152 on light is weakened, the convergence effect of the light-gathering surface 151 on light is enhanced, so that fingerprint images formed from the two sides of the correction area 16 to the center are clearer and clearer, and the optical fingerprint sensor can acquire clear.

The gradient change of the distance from the light collecting surface 151 to the prism film 11 from both sides of the correction region 16 to the center may be such that the height differences of the light collecting surfaces 151 between all adjacent prisms 15 are uniform, or such that the height differences of the light collecting surfaces 151 between the adjacent prisms 15 from both sides of the correction region 16 to the center are changed in an equal ratio array format, and the present embodiment is not limited thereto.

As shown in fig. 7, in another embodiment, the light-condensing surfaces 151 from both sides of the correction region 16 to the center of the correction region 16 may be located on the first circular arc surface 161 of the convex prism film 11. From the two sides to the center of the correction region 16, the light-collecting surfaces 151 of all the prisms 15 may be located on the first circular arc surface 161, that is, the light-collecting surfaces 151 of all the prisms 15 may be connected to form the first circular arc surface 161, and the first circular arc surface 161 protrudes toward the prism film 11. By providing the light condensing surface 151 in the correction region 16 in such a manner, on the one hand, the cross-sectional area of the light condensing surface 151 from both sides to the center of the correction region 16 gradually increases, and on the other hand, the angle of the included angle between the light condensing surface 151 from both sides to the center of the correction region 16 and the prism film 11 gradually decreases, so that a fingerprint image with gradually increased definition can be formed from both sides to the center of the correction region 16, and thus a clear fingerprint image can be captured by the optical fingerprint sensor.

As shown in fig. 7, the center of the first circular arc surface 161 may be located at the center of the modified area 16, and the first circular arc surface 161 may have a symmetrical shape. By positioning the centers of the first arc surfaces 161 formed by the light-collecting surfaces 151 of all the prisms 15 in the correction area 16 at the center of the correction area 16 and making the first arc surfaces 161 symmetrical, the light-collecting surfaces 151 of all the prisms 15 are all arranged with the center of the correction area 16 as the center of symmetry, and thus, not only is the structural symmetry of the light-collecting surfaces 151 in the correction area 16 good, but also the light-collecting surfaces 151 of the prisms 15 can form a good converging effect, and the fingerprint image formed at the center of the correction area 16 is clearest.

As shown in fig. 5 and 8, in one possible embodiment, the light-collecting surface 151 may be located between two adjacent prisms 15, and the light-collecting surface 151 connects the two adjacent prisms 15. As mentioned above, the connecting portion between two adjacent prisms 15 forms a valley bottom, when the light-gathering surface 151 other than the prism surface 152 is disposed in the prism 15, in addition to the light-gathering surface 151 being located at the top of the prism 15, the light-gathering surface 151 may also be located at the connecting portion between two adjacent prisms 15, that is, the light-gathering surface 151 is located at the valley bottom, and similarly, the included angle between the light-gathering surface 151 located at the valley bottom and the prism film 11 is smaller than the included angle between the prism surface 152 and the prism film 11, so that the light-gathering surface 151 has a converging effect on the fingerprint image light reflected by the liquid crystal panel compared with the prism surface 152, which can improve the dispersion effect of the prism film 11 on the fingerprint image reflected light, and further form a clear fingerprint image by the prism film 11 in the correction area 16, and no further description.

Specifically, the height of the light-condensing surface 151 may gradually increase from both sides of the modified area 16 to the center of the modified area 16. As shown in fig. 5 and 8, since the light-condensing surface 151 is located at the bottom of the valley connecting two adjacent prisms 15, in order to increase the ratio of the light-condensing surface 151 of the prism 15 from both sides to the center of the correction region 16, the height of the light-condensing surface 151 may be gradually increased, so that the cross-sectional width of the light-condensing surface 151 is gradually increased, and the cross-sectional area of the light-condensing surface 151 is increased, and conversely, the area of the prism surface 152 connected to the light-condensing surface 151 is gradually decreased, and the prism 15 up to the center may include only the light-condensing surface 151 without including the prism surface 152, so that the dispersion effect on light from both sides to the center of the correction region 16 is gradually decreased, and the center region may even allow light to be transmitted straight without dispersion effect, thereby making the formed fingerprint image.

Similarly, as shown in fig. 5, for the structure form that the light-condensing surface 151 is located at the valley bottom connecting the adjacent prisms 15, the light-condensing surface 151 may also be parallel to the prism film 11, and the distance from the laser surface to the prism film 11 may also be changed in a gradient manner from the two sides of the modification area 16 to the center of the modification area 16, which is not described herein again.

As shown in fig. 8, for a configuration in which the light-condensing surface 151 is located at the valley bottom of the connecting adjacent prisms 15, in another embodiment, the light-condensing surface 151 from both sides of the modified region 16 to the center of the modified region 16 may be located on the second circular arc surface 162 protruding toward the top of the prism 15. In all the prisms 15 in the correction area 16, the light-condensing surfaces 151 located at the bottom of the valley may be connected to form a second circular arc surface 162, and unlike the first circular arc surface 161, the height of the light-condensing surfaces 151 gradually increases from both sides to the center of the correction area 16, so that the second circular arc surface 162 protrudes toward the top of the prism 15.

In addition, like the first arc surface 161, the center of the second arc surface 162 may also be located at the center of the modification area 16, and the second arc surface 162 may have a symmetrical shape, which is not described herein again. It should be noted that the entire modified region 16 may be a circle with a central symmetry, or the entire modified region 16 may be a rectangle or a triangle with an equiaxed symmetry, so that the first circular arc surface 161 and the second circular arc surface 162 may have a central symmetry structure or an axisymmetric structure.

As shown in fig. 6 and 9, in one possible embodiment, the top of the prism 15 may have a light-collecting surface 151, the light-collecting surface 151 connecting two oppositely disposed prism faces 152 of the prism 15; the light-collecting surface 151 may be provided between two adjacent prisms 15, and the light-collecting surface 151 connects the two adjacent prisms 15.

As described above, the light condensing surface 151 may be provided only on the top of the prism 15, i.e., the valley and peak of the prism 15; the light-condensing surface 151 may be provided only at the connecting portion between the adjacent prisms 15, that is, at the bottom of the valley of the prism 15; alternatively, the light-condensing surfaces 151 may be provided on the top of each prism 15 and between two adjacent prisms 15, that is, the light-condensing surfaces 151 may be provided on both the bottom and the top of each prism 15, so that the prism structure 14 may have a configuration in which the light-condensing surfaces 151 are provided on the top of each prism 15 and the connecting portion between the adjacent prisms 15 from both sides to the center of the correction region 16. The convergence effect of the prisms 15 from the two sides to the center of the correction area 16 on the reflected light of the fingerprint image is enhanced, the dispersion effect of the prism film 11 on the reflected light of the fingerprint image can be effectively improved, and a clear fingerprint image can be formed through the prism film assembly 1 of the correction area 16.

Specifically, as shown in fig. 6 and 9, in the same manner as the light-condensing surface 151 is provided only on the top of the prism 15 and the light-condensing surface 151 is provided only on the bottom of the valley of the prism 15, in the configuration in which the top of the prism 15 has the light-condensing surface 151 and the bottom of the valley of the prism 15 also has the light-condensing surface 151, the height of the light-condensing surface 151 on the top of the prism 15 may gradually decrease from both sides of the correction region 16 to the center of the correction region 16, and the height of the light-condensing surface 151 located between two adjacent prisms 15 may gradually increase from both sides of the correction region 16 to the center of the correction.

In one embodiment, as shown in fig. 6, in the form of the prism 15 having the light-collecting surface 151 on the top and the light-collecting surface 151 on the bottom of the bottom, the light-collecting surface 151 may be parallel to the prism film 11, and the cross-sectional width of the light-collecting surface 151 may gradually increase from the two sides of the correction region 16 to the center of the correction region 16, regardless of the light-collecting surface 151 on the top of the prism 15 or the light-collecting surface 151 on the bottom of the prism 15. So that the light reflected by the fingerprint image on the liquid crystal panel passes through the light-gathering surface 151 in a small angle refraction or linear transmission manner, thereby reducing the dispersion phenomenon of the prism film 11 on the light reflected by the fingerprint image, and forming a relatively clear fingerprint image through the prism film 11.

As shown in fig. 9, in another embodiment, in a configuration in which the top of the prism 15 has the light-condensing surface 151 and the bottom of the prism 15 also has the light-condensing surface 151, the light-condensing surfaces 151 from both sides of the correction region 16 to the center of the correction region 16 may be located on the third arc surface 163 protruding toward the prism film 11 and the fourth arc surface 164 protruding toward the top of the prism 15.

In the same manner as the above-mentioned two structures that the light-collecting surface 151 on the top of the prism 15 is located on the first arc surface 161 protruding toward the prism film 11, and the light-collecting surface 151 on the bottom of the valley of the prism 15 is located on the second arc surface 162 protruding toward the top of the prism 15, the light-collecting surfaces 151 are provided on the top of the prism 15 and the bottom of the valley of the prism 15, and the light-collecting surfaces 151 on the upper and lower sides may be located on the third arc surface 163 and the fourth arc surface 164, respectively, the third arc surface 163 protrudes toward the prism film 11, and the fourth arc surface 164 protrudes toward the top of the prism 15.

Similarly, the centers of the third arc surface 163 and the fourth arc surface 164 may be located at the center of the correction region 16, and the third arc surface 163 and the fourth arc surface 164 may have symmetrical shapes, which is not described herein again.

In addition to the above-described improvement in the phenomenon that the fingerprint signal is dispersed by the prism film 11 by using the light-condensing surface 151 other than the prism surface 152, as shown in fig. 10 and 11, in one possible embodiment, the light-condensing surface 151 may be the prism surface 152 of the prism 15. Through adopting one of them prism face 152 of two prism faces 152 of prism 15 both sides as the spotlight face 151, make the contained angle between prism face 152 as spotlight face 151 and the prism membrane 11 be less than the contained angle between another prism face 152 and the prism membrane 11 to the effect of converging of the last fingerprint image of liquid crystal display panel through spotlight face 151 can effectively be improved prism membrane 11 and to the dispersion of fingerprint signal, the light that makes the fingerprint image reflection forms comparatively clear fingerprint image through the prism membrane 11 of correction region 16.

As shown in fig. 11 and 12, in one possible embodiment, the prisms 15 may be symmetrical to each other about the center of the correction area 16, and the prisms 15 may have a first prism face 153 near the center and a second prism face 154 far from the center, and the light-condensing face 151 may be one of the first prism face 153 and the second prism face 154.

As described above, the correction region 16 may be a center-symmetric structure or an axis-symmetric structure, and in the prism structure 14 in the correction region 16, all the prisms 15 are symmetric with each other at the center of the correction region 16, and may be center-symmetric or axis-symmetric, and the prism 15 has a first prism face 153 near the center and a second prism face 154 far from the center. By making one of the first prism surface 153 and the second prism surface 154 the light-condensing surface 151, that is, the angle between one of the two prism surfaces 152 and the prism film 11 is smaller than the angle between the other prism surface and the prism film 11, the light reflected by the fingerprint image on the liquid crystal panel is converged toward the center of the correction area 16 through the light-condensing surface 151, so as to weaken the dispersion effect of the prism film 11 on the fingerprint signal.

Since all the prisms 15 in the correction area 16 are distributed symmetrically with respect to the center of the correction area 16, the light converging effects of the mutually symmetrical areas in the correction area 16 are consistent, which can reduce the mutual overlapping phenomenon between the fingerprint signals refracted by the prism film 11, improve the condition that the fingerprint signals are dispersed by the prism film 11, and further enable the light reflected by the fingerprint image to form a clearer fingerprint image through the correction area 16.

In order to make the light-condensing surface 151 have a better effect of condensing light, in one possible embodiment, the light-condensing surface 151 and the prism film 11 may have a first included angle 17 therebetween, and the angle of the first included angle 17 may gradually decrease from both sides of the modified area 16 to the center of the modified area 16.

As shown in fig. 10 and 11, an included angle between the light-condensing surface 151 of the first prism surface 153 and the second prism surface 154 and the prism film 11 is a first included angle 17, and an angle of the first included angle 17 gradually decreases from two sides of the correction region 16 to the center of the correction region 16. Thus, the inclination of the normal line of the light condensing surface 151 with respect to the normal line of the prism film 11 becomes smaller from both sides to the center of the correction region 16, and even if the normal line of the light condensing surface 151 at the center of the correction region 16 is parallel to the normal line of the prism film 11, that is, the light condensing surface 151 at the center of the correction region 16 is parallel to the prism film 11.

When the light of fingerprint image reflects to the spotlight face 151 of prism 15 like this, by revising the regional 16 both sides to the contained angle between the spotlight face 151 and the prism membrane 11 of prism 15 at center reduce gradually, spotlight face 151 gathers light from revising regional 16 both sides to the center, the light at center does not take place the refraction and straight line transmission even, can reduce the dispersion effect of prism membrane 11 to the light of fingerprint image reflection like this, make light not take place the dispersion even when revising regional 16 center, thereby make the fingerprint image still have better definition behind prism membrane 11, with the influence that reduces prism membrane 11 to the fingerprint signal, so that effective discernment to the fingerprint image.

Alternatively, the non-light-condensing surface 151 of the first prism surface 153 and the second prism surface 154 may have a second included angle 18 with the prism film 11, and the angle of the second included angle 18 is fixed. As shown in FIG. 10 and

as shown in fig. 11, by fixing the angle between the non-light-condensing surface 151 of the first prism surface 153 and the second prism surface 154 and the prism film 11, and by gradually decreasing the angle between the light-condensing surface 151 and the prism film 11 from the both sides to the center of the correction region 16, the inclination of the light-condensing surface 151 with respect to the prism film 11 becomes smaller from the both sides to the center of the correction region 16, that is, the effect of the prisms 15 from the both sides to the center of the correction region 16 on the dispersion of the fingerprint image becomes weaker, so that the sharpness of the fingerprint image formed from the both sides to the center of the correction region 16 becomes higher.

Specifically, the first included angle 17 may range from 0 to 45 degrees, and the second included angle 18 may range from 45 degrees. The included angle between the non-light-condensing surface 151 and the prism film 11 is set to be 45 degrees, the angle range between the light-condensing surface 151 and the prism film 11 is 0-45 degrees, the first included angle 17 can be gradually reduced to be 0 degree from 45 degrees from two sides to the center of the correction area 16, therefore, the inclination degree of the light-condensing surface 151 relative to the prism film 11 is smaller and smaller, the dispersion effect of the prism film 11 on the light reflected by the fingerprint image is weaker and weaker, the convergence effect is enhanced until the light-condensing surface 151 of the prism 15 at the center of the correction area 16 is parallel to the prism film 11, the prism film 11 at the position has no dispersion effect on the light reflected by the fingerprint image, and a clear fingerprint image can be formed.

Illustratively, the gradient of the decrease angle of the first included angle 17 from the two sides of the modification region 16 to the center of the modification region 16 may range from 1 to 3 °, that is, the angle of the first included angle 17 between the light-condensing surface 151 of the latter and the prism film 11 in the two adjacent prisms 15 in the direction from the two sides of the modification region 16 to the center is 1 to 3 ° smaller than the angle of the first included angle 17 of the former. For example, the gradient in which the first included angle 17 decreases from both sides of the modified region 16 to the center may be 1 °, 2 °, or 3 °.

The prism membrane module that this embodiment provided is applicable to the liquid crystal display who supports fingerprint identification function under the screen, has the fingerprint identification region in this liquid crystal display's the display area, and the prism membrane module is arranged in liquid crystal display's backlight unit for improve the angular distribution of light, improve liquid crystal display's luminance. The prism film assembly comprises at least one layer of prism film, the first surface of the prism film is provided with a prism structure, the prism structure comprises a plurality of prisms which are uniformly distributed on the first surface, and light emitted by the backlight source is converged by the prism surface of the prism to improve the brightness; the correction area is arranged on the first surface of the prism film, the correction area corresponds to the fingerprint identification area on the liquid crystal display screen, the prism in the correction area is provided with the light-gathering surface, the included angle between the light-gathering surface and the prism surface is smaller than the included angle between the prism surface of the prism outside the correction area and the prism film, when light reflected by a fingerprint image on the screen passes through the light-gathering surface, the light-gathering surface can generate refracted light rays towards the center of the correction area or directly transmit the light rays without refraction, so that the light rays have better convergence effect, the influence of the prism film on a fingerprint signal is smaller, the signal is dispersed to a smaller extent or does not disperse, a fingerprint image with better definition can be formed, and effective identification of fingerprints under the screen of the liquid crystal display screen is realized.

Example two

Fig. 12 is a schematic structural diagram of an optical fingerprint identification device under a screen according to an embodiment of the present invention. As shown in fig. 12, the present embodiment provides an optical fingerprint identification device 100 under a screen, which includes a liquid crystal display having a liquid crystal panel 10 and a backlight module 20, and an optical fingerprint sensor 30, wherein the backlight module 20 and the optical fingerprint sensor 30 are sequentially disposed under the liquid crystal panel 10, and the backlight module 20 includes the prism film assembly 1 according to the first embodiment.

As shown in fig. 12, optical fingerprint identification device 100 under screen of this embodiment, mainly constitute by liquid crystal display and optical fingerprint sensor 30, liquid crystal display includes liquid crystal panel 10 and backlight unit 20, backlight unit 20 and optical fingerprint sensor 30 set gradually in liquid crystal panel 10 below, it is regional to have the fingerprint identification in the display area of liquid crystal panel 10, when carrying out fingerprint identification, the backlight or the fingerprint detection light that is used for fingerprint identification shines the fingerprint on the fingerprint identification region through the screen, the reflected fingerprint image shines to optical fingerprint sensor 30 through backlight unit 20, discern the fingerprint image by optical fingerprint sensor 30.

Specifically, the backlight module 20 is provided with the prism film assembly 1, and the prism film assembly 1 may be located between the liquid crystal panel 10 and the diffusion sheet 21 of the backlight module 20. The specific structure, function and operation principle of the prism film assembly 1 have been described in detail in the first embodiment, and are not described herein again.

The off-screen optical fingerprint identification device provided by the embodiment mainly comprises a liquid crystal display screen and an optical fingerprint sensor, wherein the liquid crystal display screen comprises a liquid crystal panel and a backlight module, and the backlight module and the optical fingerprint sensor are sequentially arranged below the liquid crystal panel; the backlight module is internally provided with a prism film assembly for improving the angular distribution of light and improving the brightness of the liquid crystal display screen, the prism film assembly comprises at least one layer of prism film, a prism structure is arranged on the first surface of the prism film, the prism structure comprises a plurality of prisms which are uniformly distributed on the first surface, and the light emitted by the backlight source is converged by the prism surface of the prism to improve the brightness; the correction area is arranged on the first surface of the prism film, the correction area corresponds to the fingerprint identification area on the liquid crystal panel, the prism in the correction area is provided with the light-gathering surface, the included angle between the light-gathering surface and the prism surface is smaller than the included angle between the prism surface of the prism outside the correction area and the prism film, when light reflected by a fingerprint image on a screen passes through the light-gathering surface, the light-gathering surface can generate refracted light rays towards the center of the correction area or directly transmit the light rays without refraction, so that the light rays have better convergence effect, the influence of the prism film on a fingerprint signal is smaller, the signal is dispersed to a smaller degree or is not dispersed, and a fingerprint image with better definition can be formed so as to realize effective identification on the fingerprint under the screen of the liquid crystal display screen.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. The prism film assembly is suitable for a liquid crystal display screen supporting a fingerprint identification function under the screen, and is positioned on a backlight module of the liquid crystal display screen, and a display area of the liquid crystal display screen comprises a fingerprint identification area.

2. The prismatic film assembly of claim 1, wherein said light collection surface is a surface other than a prism surface of said prism.

3. The prismatic film assembly of claim 2, wherein said light collection surface is positioned on top of said prism and connects oppositely disposed two of said prism faces of said prism.

4. The prismatic film assembly of claim 3, wherein the height of said light-condensing surface is gradually decreased from both sides of said modified region to the center of said modified region.

5. The prismatic film assembly of claim 2, wherein said light collection surface is positioned between and connects two adjacent prisms.

6. The prismatic film assembly of claim 5, wherein the height of said light-condensing surface is gradually increased from both sides of said modified region to the center of said modified region.

7. The prismatic film assembly of claim 2, wherein said light collection surface is provided on the top of said prism, said light collection surface connecting oppositely disposed two of said prism faces of said prism; and the light-gathering surface is arranged between every two adjacent prisms and is connected with the two adjacent prisms.

8. The prism film assembly of claim 7, wherein the height of the light-collecting surface at the top of the prism is gradually decreased from the both sides of the modified region to the center of the modified region, and the height of the light-collecting surface between two adjacent prisms is gradually increased from the both sides of the modified region to the center of the modified region.

9. The prism film assembly of any one of claims 3 to 8, wherein the light-condensing surface is parallel to the prism film, and the distance from the light-condensing surface to the prism film varies in a gradient from both sides of the modified region to the center of the modified region.

10. The prismatic film assembly of any one of claims 3-8, wherein said light collection surface has a cross-sectional width that increases from both sides of said modified region to the center of said modified region.

11. The prism film assembly of claim 4, wherein the light condensing surfaces from both sides of the correction region to the center of the correction region are located on a first circular arc surface convex toward the prism film.

12. The prismatic film assembly of claim 11, wherein the center of said first circular arc surface is located at the center of said modified region and said first circular arc surface is symmetrical in shape.

13. The prismatic film assembly of claim 6, wherein said light collecting surface from both sides of said modified region to the center of said modified region is located on a second circular arc surface convex toward the top of said prism.

14. The prismatic film assembly of claim 13, wherein said second circular arc surface has a center located at a center of said modified region, and said second circular arc surface is symmetrical in shape.

15. The prism film assembly of claim 8, wherein the light condensing surfaces from both sides of the correction region to the center of the correction region are located on a third arc surface convex toward the prism film and a fourth arc surface convex toward the top of the prism.

16. The prismatic film assembly of claim 15, wherein the centers of said third circular arc surface and said fourth circular arc surface are located at the center of said modified zone, and wherein said third circular arc surface and said fourth circular arc surface are symmetrically shaped.

17. The prismatic film assembly of claim 1, wherein said light collection surface is a prism surface of said prism.

18. The prismatic film assembly of claim 17, wherein said prisms are symmetrical to each other about a center of the correction area, and said prisms have a first prism face closer to the center and a second prism face further from the center, said light collection face being one of said first prism face and said second prism face.

19. The prismatic film assembly of claim 18, wherein said light collecting surface and said prismatic film have a first included angle therebetween, said first included angle decreasing from both sides of said modified region to the center of said modified region.

20. The prism film assembly of claim 19, wherein a second included angle is formed between the non-light-condensing surface of the first prism surface and the second prism surface and the prism film, and the angle of the second included angle is constant.

21. The prismatic film assembly of claim 20, wherein said first included angle is in the range of 0 ° -45 ° and said second included angle is 45 °.

22. The prismatic film assembly of claim 20, wherein said first included angle decreases in angle in a gradient ranging from 1-3 ° from either side of said modified region to the center of said modified region.

23. The prismatic film assembly of any of claims 1-8, wherein said prismatic film assembly comprises a first prismatic film and a second prismatic film stacked in sequence, the prismatic directions of said prismatic structures of said first prismatic film and said second prismatic film being perpendicular to each other; the first prism film is close to the liquid crystal panel relative to the second prism film, and the correction area is located on at least one of the first prism film and the second prism film.

24. The prismatic film assembly of claim 23, wherein said modified region is on said first prismatic film.

25. An optical fingerprint identification device under a screen, comprising a liquid crystal display screen having a liquid crystal panel and a backlight module, and an optical fingerprint sensor, wherein the backlight module and the optical fingerprint sensor are sequentially disposed under the liquid crystal panel, and wherein the backlight module comprises the prism film assembly of any one of claims 1 to 24.