TWI792084B - image sampling device - Google Patents

Abstract

An image sampling device, comprising: a light source component having opposite first surfaces and second surfaces along the thickness direction; a liquid crystal display module having opposite first surfaces and second surfaces along the thickness direction surface, the second surface of the liquid crystal display module is set towards the first surface of the light source part, wherein there is an air gap between the liquid crystal display module and the light source part, and the liquid crystal display module includes: a scattering layer for The incident light is scattered; the light-transmitting cover plate has opposite first and second surfaces along the thickness direction, the first surface of the light-transmitting cover plate is suitable for contacting the object to be sampled, and the light-transmitting cover plate The second surface of the light cover is set facing the first surface of the liquid crystal display module; the sensor component is used for sampling the incident light reflected from the light transmission cover. The scheme provided by the invention can realize image sampling based on the principle of total reflection under the liquid crystal display screen, optimize the imaging effect, and improve the imaging definition.

Description

image sampling device

The present invention relates to the technical field of image sampling, in particular to an image sampling device.

With the development of information technology, biometric identification technology is playing an increasingly important role in ensuring information security. Among them, fingerprint identification has become one of the key technical means for identification and device unlocking widely used in the mobile Internet field. Under the trend of increasing screen-to-body ratio of smart devices, traditional capacitive fingerprint recognition technology can no longer meet the demand, while ultrasonic fingerprint recognition technology has problems in terms of technology maturity and cost. Therefore, optical fingerprint recognition technology It is expected to become the mainstream technical solution of fingerprint recognition.

Existing optical fingerprint recognition schemes are based on the imaging principle of geometric optical lenses. The fingerprint modules used include microlens arrays, optical spatial filters and other components, which have many disadvantages such as complex structures, thick modules, small sensing ranges, and high costs. Compared with the aforementioned existing optical fingerprint recognition solutions, the lensless optical under-screen fingerprint recognition technology realized by the total reflection imaging principle of physical optics has the advantages of simple structure, thin module, large sensing range, and low cost.

On the other hand, the display screen of the smart device is mainly realized by two principles of Liquid Crystal Display (LCD for short) and Organic Light-Emitting Diode (OLED for short). In comparison, LCD screens have the advantages of low cost and easy manufacture. However, the existing under-screen fingerprint solutions of liquid crystal displays can only perform image sampling based on ordinary reflection, resulting in poor imaging effect and low image definition. As mentioned in the background art, the existing under-screen fingerprint solutions of liquid crystal displays can only sample images based on ordinary reflection, and the imaging effect is poor and the image definition is low.

Specifically, referring to FIG. 1 , along the thickness direction (the z direction shown in the figure), the existing LCD fingerprint sensor 1 may include from top to bottom: a transparent cover plate 10, an LCD stack (stack) 11, a backlight module 12 and Sensor part 15. Wherein, along the z direction, the LCD stack 11 may include: an upper polarizer (polarizer) 110, a color filter (color filter) 111, an upper light-transmitting plate 112, a liquid crystal (Liquid Crystal, LC for short) layer 113, The lower transparent plate 114 and the lower polarizer 115 . The rectangular areas marked by dotted lines in FIG. 1 are light paths, and each light path corresponds to a pixel unit on the sensor component 15 . Therefore, one light path can equivalently represent one LCD pixel (pixel). The upper polarizer 110 and the lower polarizer 115 work together to make the LCD pixels in an off state and not allow light to pass through. For example, when the LCD fingerprint sensor 1 is powered off, the light path is in a non-conductive state, and the light cannot pass through the LCD stack 11 to reach the transparent cover 10 . The upper light-transmitting plate 112 may be an upper glass plate (glass), and the lower light-transmitting plate 114 may be a lower glass plate.

The upper polarizer 110 and the lower polarizer 115 work together to make the LCD pixels in an on state, allowing light to pass through. As shown in FIG. 1 , the light path is in the conduction state at this time, and the light can pass through the LCD stack 11 to reach the transparent cover 10 for reflection, and then carry the fingerprint information of the finger placed on the other side of the transparent cover 10 to the sensor unit 15 . Further, an Optical Clear Adhesive (OCA for short) layer 14 is filled between the light-transmitting cover plate 10 and the LCD stack 11 . Further, there is an air gap (may be referred to as an air gap) 13 between the LCD stack 11 and the backlight module 12 .

Therefore, one purpose of the present invention is to provide a solution to the technical problem of how to realize image sampling based on the principle of total reflection under the liquid crystal display screen.

Therefore, in order to solve the above-mentioned technical problems, an embodiment of the present invention provides an image sampling device, including: a light source component having opposite first and second surfaces along the thickness direction; a liquid crystal display module, the liquid crystal display module The group has opposite first and second faces along the thickness direction, the second face of the liquid crystal display module is set facing the first face of the light source part, wherein there is an air gap between the liquid crystal display module and the light source part , the liquid crystal display module includes: a scattering layer for scattering incident light; a light-transmitting cover plate, the light-transmitting cover plate has an opposite first surface and a second surface along the thickness direction, the first surface of the light-transmitting cover plate One side is suitable for being in contact with the object to be sampled, and the second side of the transparent cover is set facing the first side of the liquid crystal display module; the sensor component is used for sampling the incident light reflected from the transparent cover.

Preferably, the scattering layer is made of a polymer network liquid crystal material, and when the first voltage is applied to the scattering layer, the scattering layer scatters the incident light.

Preferably, the first voltage is determined according to the thickness of the scattering layer.

Preferably, the liquid crystal display module further includes: an upper polarizer, a color filter, an upper light-transmitting plate, a liquid crystal layer, a lower glass plate, and a lower polarizer sequentially arranged along a first direction, wherein the first direction is the liquid crystal The first surface of the display module points to the direction of the second surface; the scattering layer is located between the lower polarizer and the lower glass plate.

Preferably, the sensor component is integrated in the LCD module.

Preferably, the liquid crystal display module further includes: an upper polarizer, a color filter, an upper light-transmitting plate, a liquid crystal layer, a lower glass plate, and a lower polarizer sequentially arranged along a first direction, wherein the first direction is the liquid crystal The first surface of the display module points to the direction of the second surface; the sensor component is integrated on the upper transparent plate or the lower glass plate.

Preferably, the sensor component is arranged between the transparent cover plate and the liquid crystal display module.

Preferably, the sensor component is arranged between the liquid crystal display module and the light source component.

Preferably, on a plane perpendicular to the thickness direction, the sensor component is disposed outside the area surrounded by the sides of the liquid crystal display module; the image sampling device also includes: a deflection component, disposed in the air gap, The deflection component is used to deflect incident light reflected from the light-transmitting cover plate to the sensor component.

Preferably, the deflection component is located on the same plane as the sensor component, and the plane is perpendicular to the thickness direction. Preferably, the deflection component is a tapered waveguide, and the cone tip of the tapered waveguide is set in a direction away from the sensor component .

Preferably, the light source part includes: a display light source, used to provide illumination when the sensor part is in a non-working state; a detection light source, used to provide illumination when the sensor part is in an active state.

Compared with the prior art, the technical solutions of the embodiments of the present invention have the following beneficial effects:

An embodiment of the present invention provides an image sampling device, including: a light source component, the light source component has opposite first and second surfaces along the thickness direction; a liquid crystal display module, the liquid crystal display module has a second opposite surface along the thickness direction One side and the second side, the second side of the liquid crystal display module is set towards the first side of the light source part, wherein there is an air gap between the liquid crystal display module and the light source part, and the liquid crystal display module includes: A scattering layer, used to scatter the incident light; a light-transmitting cover plate, the light-transmitting cover plate has opposite first and second surfaces along the thickness direction, the first surface of the light-transmitting cover plate is suitable for The sampling object is in contact, and the second surface of the light-transmitting cover is set facing the first surface of the liquid crystal display module; the sensor component is used for sampling the incident light reflected from the light-transmitting cover.

The efficacy of the present invention lies in that compared with the existing LCD image sampling device, the scheme of this embodiment can realize image sampling based on the principle of total reflection under the liquid crystal display screen, optimize the imaging effect, and improve the imaging clarity. Specifically, a scattering layer is added in the liquid crystal display module to scatter the incident light entering the liquid crystal display module, creating conditions for total reflection of the incident light when it reaches the light-transmitting cover plate. In other words, with the solution of this embodiment, even if the incident light emitted by the light source part is totally reflected when it reaches the second surface of the LCD module due to the existence of the air gap, the incident light entering the LCD module can be scattered. Scattering occurs in the layer, which is equivalent to the translation of the light source to the location of the scattering layer, and the scattered light can "again" undergo total reflection when it reaches the transparent cover, making it possible to perform image sampling based on the principle of total reflection. Thus, by shifting the backlight up in a disguised phase, the solution of this embodiment can effectively eliminate the influence of the air gap between the liquid crystal display module and the light source component on the imaging result.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same numerals.

For the prior art shown in Figure 1, the inventors of the present application have found through analysis that in practical applications, the backlight module 12 can reuse the display panel of the smart device, and other components such as the light-transmitting cover plate 10 and the LCD stack 11 are pre-installed. The integrated package is integrated and then assembled to a suitable position on the display panel, which separates the backlight module 12 from other parts of the image sampling device 1 and inevitably introduces an air gap 13 .

Taking the light source O on the backlight module 12 as an example, if there is no air gap 13, when the light path is turned on, the incident light emitted by the light source O can reach the light-transmitting cover plate 10 and be totally reflected at point A. However, due to the existence of the air gap 13 , the incident light emitted by the light source O is totally reflected at point B when it reaches the LCD stack 11 , and cannot actually reach the transparent cover plate 10 .

Therefore, due to the existence of the air gap 13, the light emitted by the backlight module 12 has undergone total reflection when it enters the LCD stack 11, so that the LCD fingerprint sensor 1 cannot perform fingerprint image sampling based on the principle of total reflection, but only Fingerprint image sampling can be performed based on ordinary reflection, but the imaging effect is poor and the image definition is low.

In order to solve the above-mentioned technical problems, an embodiment of the present invention provides an image sampling device, including: a light source component, the light source component has opposite first and second surfaces along the thickness direction; a liquid crystal display module, the liquid crystal display module along the The thickness direction has opposite first and second surfaces, the second surface of the liquid crystal display module is set facing the first surface of the light source part, wherein there is an air gap between the liquid crystal display module and the light source part, the The liquid crystal display module includes: a scattering layer, which is used to scatter incident light; Suitable for being in contact with the object to be sampled, the second surface of the light-transmitting cover is set facing the first surface of the liquid crystal display module; the sensor component is used for sampling the incident light reflected from the light-transmitting cover.

The scheme of this embodiment can realize image sampling based on the principle of total reflection under the liquid crystal display screen, optimize the imaging effect, and improve the imaging clarity. Specifically, a scattering layer is added in the liquid crystal display module to scatter the incident light entering the liquid crystal display module, creating conditions for total reflection of the incident light when it reaches the light-transmitting cover plate. In other words, with the solution of this embodiment, even if the incident light emitted by the light source part is totally reflected when it reaches the second surface of the LCD module due to the existence of the air gap, the remaining incident light entering the LCD module can be The scattering of the scattering layer is equivalent to the translation of the light source to the location of the scattering layer. When the scattered light reaches the light-transmitting cover, total reflection can occur again, making image sampling based on the principle of total reflection possible. Thus, by moving the backlight up in a disguised phase, the solution of this embodiment can effectively eliminate the influence of the air gap between the liquid crystal display module and the light source component on the imaging result.

Further, the solution of this embodiment does not need to improve the structure of the light source part, nor does it need to improve the combination of the light source part and the liquid crystal display module, and can realize the total reflection of light while retaining the air gap, and has low requirements on the manufacturing process. , which is beneficial to realize and the realization cost is low.

Next, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same reference numeral is attached to the same part. Each embodiment is just an illustration, and of course it is possible to partially replace or combine the configurations shown in different embodiments. In the modified example, descriptions of matters common to the first embodiment are omitted, and only differences are described. In particular, the same function and effect produced by the same structure will not be mentioned one by one for each embodiment.

In order to make the above objects, features and beneficial effects of the present invention more comprehensible, specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

Fig. 2 is a schematic diagram of an image sampling device according to the first embodiment of the present invention.

The image sampling device 2 described in this embodiment may be an optical under-screen image sampling device, such as an optical under-screen fingerprint sampling device based on the principle of optical total reflection.

The image sampling device 2 may be suitable for sampling an image of an object to be sampled, the object to be sampled may be a finger, and the image may be a fingerprint image.

Specifically, referring to FIG. 2, the image sampling device 2 may include: a light source component 20, the light source component 20 has an opposite first surface 20a and a second surface 20b along the thickness direction (z direction); a liquid crystal display module 21, The liquid crystal display module 21 has an opposite first surface 21a and a second surface 21b along the thickness direction (z direction), and the second surface 21b of the liquid crystal display module 21 is disposed toward the first surface 20a of the light source component 20, wherein , there is an air gap 22 between the liquid crystal display module 21 and the light source part 20, the liquid crystal display module 21 may include: a scattering layer 210 for scattering incident light; a light-transmitting cover plate 23, the light-transmitting cover Plate 23 has opposite first surface 23a and second surface 23b along the thickness direction (z direction). The two surfaces 23b are set towards the first surface 21a of the LCD module 21; the sensor component 24 is used to sample the incident light reflected from the transparent cover plate 23.

In a specific implementation, the sensor component 24 can be a photosensor, for example, it can include a plurality of pixels arranged in an array, and for each pixel, the pixel includes a photodiode (Photo Diode, referred to as PD), as shown in FIG. 2 The small rectangular box indicated by the reference number 24 is shown. It should be pointed out that the positional relationship between the light path and the pixel in the figure is only an exemplary display. In practical applications, there may be a one-to-one correspondence between light paths and pixels, or one light path may correspond to multiple pixels.

For example, continuing to refer to Figure 2, when performing image sampling operations, specific voltages can be applied to one or more pixels, so that only the light paths corresponding to these pixels are turned on, so as to realize only local sampling The effect of the region image.

In a specific implementation, voltages may be applied to the pixels sequentially by row or column, so as to turn on the light paths sequentially, and sample the overall image of the object to be sampled.

In a specific implementation, the light source component 20 may be a backlight module.

The first surface 20 a of the light source component 20 may not be in direct contact with the second surface 21 b of the LCD module 21 , and the gap between the two surfaces is the air gap 22 .

Alternatively, although the first surface 20a of the light source component 20 is closely attached to the second surface 21b of the liquid crystal display module 21, due to technical limitations such as the manufacturing process, the first surface 20a of the light source component 20 There is still the air gap 22 between the liquid crystal display module 21 and the second surface 21b.

In a specific implementation, the scattering layer 210 can be made of polymer network liquid crystal (PolymerNetwork Liquid Crystal, PNLC for short), and when the first voltage is applied to the scattering layer 210, the scattering layer 210 can scatter the incident light .

Specifically, the main feature of the PNLC material is that it uses a polymer (polymer) to cure through different methods (such as light or heat, etc.), and then uses the cured polymer as a support to inject liquid crystal. In this way, the spatial modulation formed by the polymer is combined with the liquid crystal in the liquid state, and the electric field of the electrode is added to form different optical properties.

Therefore, under the premise that the air gap 22 exists between the light source part 20 and the liquid crystal display module 21, the different optical properties of the PNLC material due to the influence of the electric field, after the first voltage is applied to the scattering layer, The liquid crystal material deflects according to the direction of the first voltage, and forms a relative refractive index difference with the cured polymer, so that light can be scattered after entering the scattering layer 210 . In the scattering layer 210, the network liquid crystals are distributed in the three-dimensional grid formed by the cured polymer to form a continuous channel network.

For example, what is injected into the three-dimensional grid may be a liquid crystal mixture, and the liquid crystal mixture may include: network liquid crystal; anisotropic monomer; photo-initiator; co-initiator; Mono-acrylate monomer.

When the first voltage is not applied to the scattering layer 210, the scattering layer 210 is in a transparent state, through which incident light can directly pass through, thus retaining a state of total reflection, that is, a wave guiding state. When the first voltage is applied to the scattering layer 210, the scattering layer 210 is in a non-transparent state, and the liquid crystal molecules in the scattering layer 210 are deflected to form a local contrast difference in refractive index with the cured polymer, thereby being able to scatter incident light .

Therefore, the scattering layer 210 can be equivalent to the light source component 20, which is equivalent to moving the light source component 20 above the air gap 22. In this embodiment, the scattering layer 210 is used to create a large-angle incident light, so as to form total reflection light on the transparent cover plate 23 .

In a typical application scenario, continue to refer to FIG. 2 , assuming that the corresponding light path is in the conducting state, taking the light emitted by the light source P as an example, except that the total reflection occurs at point B on the second surface 21b of the liquid crystal display module 21 Except light, the remaining incident light that can enter the liquid crystal display module 21, when reaching the scattering layer 210, when the first voltage is applied to the scattering layer 210, the incident light is scattered in the scattering layer 210, The light diverging upward from the scattering layer 210 can be totally reflected when reaching the transparent cover plate 23 , as shown at point D in the figure. The image formed by the total reflection of the light-transmitting cover plate 23 can be captured by the sensor component 24, thereby realizing an image sampling operation based on the principle of total reflection.

In a specific implementation, the first voltage can be determined according to the thickness h of the scattering layer 210. For example, the first voltage may be 10V to 40V. For example, the first voltage may be proportional to the thickness h of the scattering layer 210.

In a specific implementation, the liquid crystal display module 21 may also include: an upper polarizer 211, a color filter 212, an upper light-transmitting plate 213, a liquid crystal layer 214, a lower light-transmitting plate 215, and a lower polarizing plate arranged in sequence along the first direction 216, wherein the first direction is the direction in which the first surface 21a of the liquid crystal display module 21 points to the second surface 21b; the scattering layer 210 can be located between the lower polarizer 216 and the lower transparent plate 215. For example, the scattering layer 210 can be coated on the side of the lower transparent plate 215 facing the lower polarizer 216 .

In a specific implementation, the liquid crystal layer 214 can be made of liquid crystal material, and by applying a second voltage to the liquid crystal layer 214, the conduction of the light path can be controlled; when the liquid crystal layer 214 is not applied with the second voltage , the optical path is not conducted.

For example, the first voltage may be no less than 45V, and the second voltage may be 10V to 20V. Moreover, when the first voltage is applied to the scattering layer 210, the second voltage is applied to the liquid crystal layer 214, so that the light passing through while the light path is turned on is the scattered light.

In a specific implementation, the second voltage of the liquid crystal layer 214 can be applied by the sensor component 24. For example, in a partial fingerprint sampling scenario, a voltage may be applied to a specific pixel, and the applied voltage may be transmitted to the liquid crystal layer 214 corresponding to the pixel, so as to conduct the light path corresponding to the pixel.

In a specific implementation, through the cooperation of the upper polarizer 211 and the lower polarizer 216, all the light paths in the liquid crystal display module 21 can be turned on or not turned on at the same time. In a specific implementation, an optical adhesive layer 25 may be filled between the light-transmitting cover plate 23 and the LCD module 21 . For example, the first surface 21a of the liquid crystal display module 21 can be bonded to the second surface 23b of the transparent cover plate 23 by optical glue.

In a specific implementation, the sensor component 24 can be integrated in the liquid crystal display module 21 . For example, referring to FIG. 2 , the sensor component 24 can be integrated on the upper transparent plate 213 . Specifically, the sensor component 24 can be integrated on the side of the upper transparent plate 213 facing the color filter 212 . In a variation, the sensor component 24 can be integrated on the side of the color filter 212 facing the upper light-transmitting plate 213 . The upper light-transmitting plate 213 may be an upper glass plate.

In a specific implementation, the light source component 20 can be a display panel.

For example, the display panel can be selected from liquid crystal display, active matrix organic light emitting diode display and micro light emitting diode display. In a specific implementation, the transparent cover plate 23 can be made of glass material.

Specifically, the light-transmitting cover 23 can be integrated with protection and touch functions.

When the image sampling device 2 is used for fingerprint recognition under an optical screen, the first surface 23a of the transparent cover 23 can be used for contacting fingerprints.

From the above, by adopting the solution of this embodiment, image sampling based on the principle of total reflection can be realized under the liquid crystal display screen, the imaging effect can be optimized, and the imaging definition can be improved. Specifically, a scattering layer is added in the liquid crystal display module to scatter the incident light entering the liquid crystal display module, creating conditions for total reflection of the incident light when it reaches the light-transmitting cover plate. In other words, with the solution of this embodiment, even if the incident light emitted by the light source part is totally reflected when it reaches the second surface of the LCD module due to the existence of the air gap, the incident light entering the LCD module can be scattered. Scattering occurs in the layer, which is equivalent to the translation of the light source to the location of the scattering layer, and the scattered light can "again" undergo total reflection when it reaches the transparent cover, making it possible to perform image sampling based on the principle of total reflection. Thus, by shifting the backlight up in a disguised phase, the solution of this embodiment can effectively eliminate the influence of the air gap between the liquid crystal display module and the light source component on the imaging result.

Fig. 3 is a schematic diagram of an image sampling device according to the second embodiment of the present invention. Here, only the differences between the image sampling device 3 and the image sampling device 2 shown in FIG. 2 are mainly described.

In this embodiment, the main difference from the image sampling device 2 shown in FIG. 2 is that the sensor component 24 can be integrated in the lower light-transmitting plate 215 . For example, the sensor component 24 can be integrated on the side of the lower transparent plate 215 facing the liquid crystal layer 214 . In a specific implementation, the lower transparent plate 215 may be integrated with a thin film transistor (Thin Film Transistor, TFT for short). Further, the photodiodes and the TFTs can be distributed on the surface of the lower transparent plate 215 in parallel. The lower light-transmitting plate 215 may be a lower glass plate.

Compared with the image sampling device 3 shown in FIG. 3 , the image sampling device 2 shown in FIG. 2 has a higher light transmittance of the sensor part 24 arranged on the upper light-transmitting plate 213 , which is beneficial to obtain clear imaging. Specifically, the closer the position of the sensor component 24 is to the transparent cover 23, the shorter the return distance of the total reflection light carrying the fingerprint information is, so that the light absorption efficiency is higher.

On the other hand, since the photodiode will occupy an area, when the sensor component 24 is arranged on the upper light-transmitting plate 213, the photodiode and the TFT on the lower glass plate 215 can be aligned in the thickness direction. , increase light transmittance.

Compared with the image sampling device 2 shown in FIG. 2 , the image sampling device 3 shown in FIG. 3 is easier to realize in terms of manufacturing process, and the manufacturing process complexity is lower.

Fig. 4 is a schematic diagram of an image sampling device according to the third embodiment of the present invention. Here, only the differences between the image sampling device 4 and the image sampling device 2 shown in FIG. 2 are mainly described.

In this embodiment, the main difference from the image sampling device 2 shown in FIG. 2 is that, on a plane perpendicular to the thickness direction (z direction), the sensor component 24 can be arranged on the side of the liquid crystal display module 21 outside the enclosed area.

For example, at the angle shown in FIG. 4 , the sensor part 24 can be disposed on the left or right side of the LCD module 21 . That is, the sensor component 24 and the liquid crystal display module 21 can be two independent components.

In particular, the sensor part 24 can be arranged close to the air gap 22. Further, the image sampling device 4 may further include: a deflection component 41 disposed in the air gap 22, the deflection component 41 is used to deflect the incident light reflected from the transparent cover plate 23 to the sensor component 24. In a specific implementation, the deflection component 41 is located on the same plane as the sensor component 23, and the plane is perpendicular to the thickness direction (z direction). For example, the deflection component 41 may be a tapered waveguide, and the tapered tip 41a of the tapered waveguide is arranged in a direction away from the sensor component 24 .

In a specific implementation, the light source part 20 may include: a display light source (not shown), for providing illumination when the sensor part 24 is in a non-working state; a detection light source (not shown), for 24 Provides lighting when in working condition.

Specifically, the detection light source may be infrared illumination light. Further, the light source component 20 may also include a light guide plate (not shown).

In a typical application scenario, the light guide plate is transparent during the display state period, the display light source is turned on to provide illumination, and the user can see the light source component 20 from the first surface 23a of the transparent cover plate 23 displayed image.

During the detection state time period, the display light source is turned off, the detection light source is turned on, all the light paths in the liquid crystal display module 21 are turned on, and after the detection light at point P is scattered by the scattering layer 210, a complete The reflection, returning to the tapered waveguide 41, is deflected to the sensor element 24 on the outside, forming an image of the object to be sampled.

Thus, the sensor part 24 is arranged outside, the deflection part 41 realizes the deviation of the total reflection light, and the capture of the total reflection light can be realized without changing other manufacturing processes of the liquid crystal display module except the scattering layer 210, which is beneficial to Reduce manufacturing process complexity.

Fig. 5 is a schematic diagram of an image sampling device according to a fourth embodiment of the present invention. Here, only the differences between the image sampling device 5 and the image sampling device 2 shown in FIG. 2 are mainly described.

In this embodiment, the main difference from the image sampling device 2 shown in FIG. 2 is that the sensor component 24 can be arranged between the light-transmitting cover plate 23 and the liquid crystal display module 21 . For example, the sensor part 24 can be arranged between the second surface 23b of the light-transmitting cover plate 23 and the first surface 21a of the liquid crystal display module 21, and the space between the light-transmitting cover plate 23 and the liquid crystal display module 21 Other voids can still be filled with optical glue.

In a specific implementation, the sensor component 24 can be disposed close to the second surface 23b of the light-transmitting cover plate 23, so as to obtain a higher light transmittance.

Alternatively, the sensor component 24 can also be disposed close to the first surface 21a of the LCD module 21 .

In a specific implementation, the sensor component 24 can be made of transparent material, so as to avoid affecting the image display effect of the display panel during the non-image sampling stage.

In a specific implementation, the display (display) and the sensing (sensing) may be performed in a time-sharing manner.

That is, when performing image display, the sensor part 24 is not applied with a voltage, and the image of the light source part 20 can be displayed outside through the light-transmitting cover plate 23 without being blocked by the sensor part 24; During image sampling, voltage is applied to the sensor component 24 to obtain an image of the object to be sampled.

Therefore, the sensor component 24 is disposed outside, and the total reflection light can be captured without changing other manufacturing processes of the liquid crystal display module except the scattering layer 210 , which is beneficial to reduce the complexity of the manufacturing process. Fig. 6 is a schematic diagram of an image sampling device according to a fifth embodiment of the present invention. Here, only the differences between the image sampling device 6 and the image sampling device 2 shown in FIG. 2 are mainly described. In this embodiment, the main difference from the image sampling device 2 shown in FIG. 2 is that the sensor part 24 can be arranged between the liquid crystal display module 21 and the light source part 20. That is, the sensor component 24 can be disposed in the air gap 22 to fully utilize the space of the existing LCD fingerprint sampling device. For example, the sensor part 24 can be disposed close to the first surface 20a of the light source part 20 . Therefore, the sensor component 24 is disposed outside, and the total reflection light can be captured without changing other manufacturing processes of the liquid crystal display module except the scattering layer 210 , which is beneficial to reduce the complexity of the manufacturing process.

In this embodiment, the image sampling device 2 to the image sampling device 6 can be applied to electronic devices such as mobile phones, smart bracelets, and wrist watches. Although the present invention is disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention should be based on the scope defined in the claims.

But the above-mentioned ones are only embodiments of the present invention, and should not limit the scope of the present invention. All simple equivalent changes and modifications made according to the patent scope of the present invention and the content of the patent specification are still within the scope of the present invention. Within the scope covered by the patent of the present invention.

1: LCD fingerprint sensor 10: Translucent cover 11:LCD stack 110: upper polarizer 111: color filter 112: upper transparent plate 113: liquid crystal layer 114: lower transparent plate 115: lower polarizer 12:Backlight module 14: Optical adhesive layer 15: Sensor part 13: Air gap O: light source 2: Image sampling device 20: Light source parts 20a: First side 20b: Second side 21:LCD display module 21a: First side 21b: Second side 210: Scattering layer 22: Air gap 23: Translucent cover 23a: First side 23b: Second side 24: Sensor part 211: upper polarizer 212: color filter 213: Upper transparent plate 214: liquid crystal layer 215: lower transparent plate 216: lower polarizer 25: Optical glue layer 41: deflection part

Other features and effects of the present invention will be clearly presented in the implementation manner with reference to the drawings, wherein: Fig. 1 is the schematic diagram of a kind of LCD fingerprint sensor of prior art; Fig. 2 is a schematic diagram of an image sampling device according to the first embodiment of the present invention; Fig. 3 is a schematic diagram of an image sampling device according to the second embodiment of the present invention; Fig. 4 is a schematic diagram of an image sampling device according to the third embodiment of the present invention; Fig. 5 is a schematic diagram of an image sampling device according to a fourth embodiment of the present invention; Fig. 6 is a schematic diagram of an image sampling device according to a fifth embodiment of the present invention.

2: Image sampling device

20: Light source parts

20a: First side

20b: Second side

21:LCD display module

21a: First side

21b: Second side

210: Scattering layer

22: Air gap

23: Translucent cover

23a: First side

23b: Second side

24: Sensor part

211: upper polarizer

212: color filter

213: upper glass plate

214: liquid crystal layer

215: lower glass plate

216: lower polarizer

25: Optical glue layer

41: deflection part

Claims (13)

An image sampling device, comprising: a light source component, the light source component has opposite first surfaces and second surfaces along the thickness direction; a liquid crystal display module, and the liquid crystal display module has opposite first surfaces and second surfaces along the thickness direction The second surface, the second surface of the liquid crystal display module is set towards the first surface of the light source component, wherein the liquid crystal display module includes a scattering layer for scattering incident light, when the scattering layer is applied with a When the first voltage is applied, the scattering layer scatters the incident light; a light-transmitting cover plate, the light-transmitting cover plate has an opposite first surface and a second surface along the thickness direction, and the first surface of the light-transmitting cover plate is suitable for When in contact with an object to be sampled, the second surface of the light-transmitting cover is arranged facing the first surface of the liquid crystal display module; and a sensor component is used for sampling incident light reflected from the light-transmitting cover. The image sampling device according to claim 1, wherein the scattering layer is made of polymer network liquid crystal material. The image sampling device as claimed in claim 1, wherein the first voltage is determined according to the thickness of the scattering layer. The image sampling device as described in Claim 1, wherein the liquid crystal display module further includes: an upper polarizer arranged in sequence along the first direction, a color filter, an upper light-transmitting plate, a liquid crystal layer, and a lower light-transmitting plate and a lower polarizer, wherein the first direction is the direction in which the first surface of the liquid crystal display module points to the second surface; The scattering layer is located between the lower polarizer and the lower transparent plate. The image sampling device according to claim 1, wherein the sensor component is integrated in the liquid crystal display module. The image sampling device as described in Claim 1, wherein the liquid crystal display module further includes: an upper polarizer arranged in sequence along the first direction, a color filter, an upper light-transmitting plate, a liquid crystal layer, and a lower light-transmitting plate and a lower polarizer, wherein the first direction is the direction in which the first surface of the liquid crystal display module points to the second surface; the sensor component is integrated on the upper light-transmitting plate or the lower light-transmitting plate. The image sampling device according to claim 1, wherein the sensor component is disposed between the light-transmitting cover plate and the liquid crystal display module. The image sampling device according to claim 1, wherein the sensor part is arranged between the liquid crystal display module and the light source part. The image sampling device as claimed in claim 1, wherein, on a plane perpendicular to the thickness direction, the sensor component is arranged outside the area surrounded by the sides of the liquid crystal display module; the image sampling device also includes : a deflection component, arranged between the liquid crystal display module and the light source component, the deflection component is used to deflect the incident light reflected from the transparent cover plate to the sensor component. The image sampling device according to claim 1, wherein the deflection component and the sensor component are located on the same plane, and the plane is perpendicular to the thickness direction. The image sampling device according to claim 1, wherein the deflection component is a tapered waveguide, and the tapered tip of the tapered waveguide is arranged in a direction away from the sensor component. The image sampling device according to claim 1, wherein the light source part includes: a display light source, used to provide illumination when the sensor part is in a non-working state; a detection light source, used to provide illumination when the sensor part is in a working state lighting is provided. The image sampling device according to claim 1, wherein there is an air gap between the liquid crystal display module and the light source component.

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