TW202217528A - Image acquisition device including a light source part, an LCD module, a light-transmitting cover plate, and a sensor part - Google Patents

Abstract

An image acquisition device includes: a light source part, the light source part having a first surface and a second surfaces opposite to each other and along the thickness direction; an LCD module, the LCD module having a first surface and a second surfaces opposite to each other and along the thickness direction, and the second surface of the LCD module being adhered to the first surface of the light source part; a light-transmitting cover plate, the light-transmitting cover plate having a first surface and a second surface opposite to each other and along the thickness direction, and the first surface of the light-transmitting cover plate being configured to be in contact with an object to be collected, and the second surface of the light-transmitting cover plate being disposed facing the first surface of the LCD module; a sensor part for being used to collect incident light reflected from the light-transmitting cover plate. The solution provided by the present invention can realize image acquisition based on the principle of total reflection under the LCD screen, optimize the imaging effect, and improve the imaging clarity.

Description

Image acquisition device

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

With the development of information technology, biometric identification technology plays 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 that the screen ratio of smart devices is increasing, the traditional capacitive fingerprint recognition technology can no longer meet the demand, while the ultrasonic fingerprint recognition technology has problems in terms of technical maturity and cost. Therefore, the optical fingerprint recognition technology It is expected to become the mainstream technical solution for fingerprint identification.

Existing optical fingerprint identification solutions 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 structure, thick module, small sensing range, and high cost.

Compared with the above-mentioned existing optical fingerprint identification solutions, the lensless optical fingerprint identification 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 smart devices is mainly realized by the two principles of Liquid Crystal Display (LCD) and Organic Light-Emitting Diode (OLED). In comparison, LCD screens have the advantages of low cost and ease of manufacture.

However, the existing fingerprint solution under the LCD screen can only collect images based on ordinary reflection, resulting in poor imaging effect and low image definition.

The technical problem solved by the present invention is how to realize image acquisition based on the principle of total reflection under the LCD screen.

In order to solve the above-mentioned technical problems, an embodiment of the present invention provides an image acquisition device, comprising: a light source component, the light source component has opposite first and second surfaces along the thickness direction; an LCD module, the LCD module along the thickness direction. The thickness direction has opposite first and second surfaces, and the second surface of the LCD module is attached to the first surface of the light source component; a first surface and a second surface, the first surface of the transparent cover plate is suitable for contacting the object to be collected, the second surface of the transparent cover plate is arranged towards the first surface of the LCD module; a sensor The component is used for collecting the incident light reflected from the light-transmitting cover plate.

Optionally, an adhesive material is filled between the second surface of the LCD module and the first surface of the light source component.

Optionally, the image acquisition device further includes: an electrode, coupled to the LCD module, for controlling the difference in polarization states of incident light with different incident angles in the LCD module within a tolerable error range .

Optionally, the LCD module includes a liquid crystal layer, and the electrode applies a voltage to the liquid crystal layer to adjust the refractive index of the liquid crystal layer.

Optionally, the electrode applies a voltage to the liquid crystal layer to adjust the refractive index of the liquid crystal layer means: the electrode applies different voltages to different regions of the liquid crystal layer, so that the incident light with a larger incident angle is refracted in the region where the incident light is incident. The greater the adjustment amount of the rate.

Optionally, for the same area of the liquid crystal layer, the voltage applied by the electrode to the area varies with the incident angle of incident light incident on the area.

Optionally, when the dielectric anisotropy of the liquid crystal material filled in the area is greater than zero, the voltage applied by the electrode to the area increases with the increase of the incident angle of the incident light incident on the area; when the area is When the dielectric anisotropy of the filled liquid crystal material is less than zero, the voltage applied by the electrode to the region decreases as the incident angle of incident light incident on the region increases.

Optionally, the LCD module includes an upper polarizer, a color filter, an upper light-transmitting plate, a liquid crystal layer, a lower light-transmitting plate, and a lower polarizer arranged in sequence along a first direction, wherein the first direction The direction in which the first side of the LCD module points to the second side.

Optionally, the sensor component is integrated in the upper transparent plate or the lower transparent plate.

Optionally, the sensor component is disposed between the transparent cover plate and the LCD module.

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 acquisition device, comprising: a light source component, the light source component has opposite first and second surfaces along the thickness direction; and an LCD module, the LCD module has opposite first surfaces along the thickness direction and the second surface, the second surface of the LCD module is attached to the first surface of the light source component; 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 collected, and the second surface of the light-transmitting cover plate is disposed toward the first surface of the LCD module; the sensor component is used for collecting data from the light-transmitting cover Incident light reflected by the plate.

Compared with the existing LCD image acquisition device, the solution of this embodiment can realize image acquisition based on the principle of total reflection in a device with an LCD screen, optimize the imaging effect, and improve the imaging clarity. Specifically, the LCD module and the light source component are attached and arranged, so that the light source component is packaged in the image acquisition device as a component integrated with the LCD module, so as to eliminate the air gap between the LCD module and the light source component. Influence on the imaging results, avoid total reflection of the incident light emitted by the light source component when it reaches the LCD module, and ensure that the incident light with a large angle can enter the LCD module, and then total reflection occurs at the light-transmitting cover, so that the Image acquisition based on the principle of total reflection becomes possible.

Further, the image acquisition device further includes: an electrode coupled to the LCD module for controlling the difference of polarization states of incident light with different incident angles in the LCD module within a tolerable error range. Compared with the existing LCD screen, the image capturing device of this embodiment eliminates the air gap, so that the incident light with a larger incident angle can also be incident on the LCD module. Since the increase of the incident angle will cause the difference of the polarization state of the incident light in the LCD module to increase, the solution in this embodiment can effectively reduce the difference of the polarization state by optimizing the electrode design, so that the difference in the polarization state of the incident light can be better in the screen. Realize the total extinction of the light within the total reflection angle, and avoid the light passing through the LCD module in the non-conducting state, which causes the LCD module to fail to achieve full darkness.

As described in the background art, the existing fingerprint solution under the LCD screen can only collect images based on ordinary reflection, resulting in poor imaging effect and low image definition.

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 light-transmitting cover plate 10 , an LCD stack 11 , and a backlight module. 12 and the sensor part 15.

Wherein, along the z direction, the LCD stack 11 may include, in order from top to bottom: an upper polarizer 110 , a color filter 111 , an upper glass plate 112 , and a liquid crystal (Liquid Crystal, LC for short) layer 113 , the lower glass plate 114 and the lower polarizer 115 .

The rectangular area marked in the form of a dot-dash line in FIG. 1 is a light channel, and each light channel corresponds to a pixel unit on the sensor component 15. Therefore, one light channel 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 light cannot pass through the LCD stack 11 to reach the light-transmitting cover plate 10 .

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 turned on at this time, and the light can pass through the LCD stack 11 to 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. Part 15.

Further, an optical adhesive (Optical Clear Adhesive, OCA for short) layer 14 is filled between the transparent 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 .

The inventors of the present application have found through analysis that, in practical applications, the backlight module 12 usually reuses 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-integrated and packaged as a whole, and then assembled to The proper position on the display panel makes the backlight module 12 and other parts of the image capture device 1 separate from each other, and an air gap 13 naturally exists between the two.

Taking the light source O on the backlight module 12 as an example, without the air gap 13, the incident light emitted by the light source O can reach the light-transmitting cover plate 10 and be totally reflected at point A when the light path is turned on. 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 light-transmitting cover plate 10 .

Therefore, the existence of the air gap 13 causes the light emitted by the backlight module 12 to be totally reflected when it enters the LCD stack 11, so that the LCD fingerprint sensor 1 cannot perform fingerprint image acquisition based on the principle of total reflection, and It can only collect fingerprint images based on ordinary reflection, and the imaging effect is poor and the image clarity is low.

In order to solve the above technical problems, an embodiment of the present invention provides an image acquisition device, including: a light source component, the light source component has opposite first and second surfaces along the thickness direction; an LCD module, the LCD module along the thickness direction It has an opposite first surface and a second surface, and the second surface of the LCD module is attached to the first surface of the light source component; and the second surface, the first surface of the light-transmitting cover plate is suitable for contacting the object to be collected, and the second surface of the light-transmitting cover plate is arranged toward the first surface of the LCD module; the sensor part is used for Incident light reflected from the light-transmitting cover is collected.

The solution of this embodiment can realize image acquisition based on the principle of total reflection under the LCD screen, optimize the imaging effect, and improve the imaging clarity. Specifically, the LCD module and the light source component are attached and arranged, so that the light source component is packaged in the image acquisition device as a component integrated with the LCD module, so as to eliminate the air gap between the LCD module and the light source component. Influence on the imaging results, avoid the total reflection of the incident light emitted by the light source component when it reaches the LCD module, and ensure that the incident light with a large angle can smoothly enter the LCD module, and then total reflection occurs at the light-transmitting cover, so that the Image acquisition based on the principle of total reflection becomes possible.

Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In each figure, the same part is marked with the same reference numeral. Each embodiment is merely an illustration, and of course, the structures shown in different embodiments may be partially replaced or combined. In the modified example, descriptions of matters common to the first embodiment are omitted, and only different points will be described. In particular, the same functions and effects produced by the same structure will not be mentioned one by one in each embodiment.

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

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

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

The image capture device 2 may be adapted to capture an image of an object to be captured, the object to be captured may be a finger, and the image may be a fingerprint image.

Specifically, referring to FIG. 2 , the image capture device 2 may include: a light source part 20 , the light source part 20 has opposite first surfaces 20 a and second surfaces 20 b along the thickness direction (z direction); an LCD module 21 , the LCD 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 LCD module 21 is attached to the first surface 20a of the light source component 20 and arranged; The light-transmitting cover plate 22 has an opposite first surface 22a and a second surface 22b along the thickness direction (z-direction), and the first surface 22a of the light-transmitting cover plate 22 is suitable for the object to be collected. Contact, the second surface 22b of the transparent cover plate 22 is disposed toward the first surface 21a of the LCD module 21 ; a sensor component 23 is used to collect incident light reflected from the transparent cover plate 22 .

In a specific implementation, the sensor component 23 may be a photoelectric sensor, for example, may include a plurality of pixels arranged in an array, and for each pixel, the pixel includes a photodiode (Photo Diode, PD for short), This is shown as a small rectangular block indicated by reference numeral 23 in FIG. 2 .

It should be pointed out that the positional relationship between the light path and the pixel in the figure is only exemplary. In practical applications, light paths and pixels may be in one-to-one correspondence, or one light path may correspond to multiple pixels.

For example, continuing to refer to FIG. 2 , when performing an image acquisition operation, a voltage can be applied to a specific pixel or pixels in a targeted manner, so that only the light paths corresponding to these pixels are turned on, so as to achieve only local acquisition. The effect of the area image.

In a specific implementation, voltages can be applied to the pixels sequentially by row or by column, so as to turn on the light paths in sequence, and collect the overall image of the object to be collected.

Alternatively, all light paths of the LCD module 21 may be controlled to be turned on at the same time, as shown in FIG. 1 , or controlled so that all light paths of the LCD module 21 may be turned off at the same time.

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

In a specific implementation, an adhesive material may be filled between the second surface 21b of the LCD module 21 and the first surface 20a of the light source component 20 to ensure that there is no air between the LCD module 21 and the light source component 20 gap.

For example, the glue material may comprise optical glue.

In a specific implementation, the LCD module 21 may include: an upper polarizer 210 , a color filter 211 , an upper glass plate 212 , a liquid crystal layer 213 , a lower glass plate 214 and a lower polarizing plate 210 arranged in sequence along a first direction The sheet 215, wherein the first direction is the direction in which the first surface 21a of the LCD module 21 points to the second surface 21b. The upper glass plate 212 is an embodiment of an upper transparent plate, and the lower glass plate 214 is an embodiment of a lower transparent plate, but not limited thereto.

Specifically, the liquid crystal layer 213 can be made of liquid crystal material, and the optical path can be controlled to be turned on by applying a voltage to the liquid crystal layer 213; when the liquid crystal layer 213 is not applied with a voltage, the light path is not turned on.

Further, through the cooperation of the upper polarizer 210 and the lower polarizer 215 , all light paths in the LCD module 21 can be turned on or off at the same time.

In a specific implementation, the image acquisition device 2 in this embodiment may further include: an electrode 25 coupled to the LCD module 21 , and the electrode 25 is configured to transmit incident light of different incident angles on the LCD module 21 . The difference between the polarization states within the control is within a tolerable error range.

Specifically, the electrode 25 may include an upper electrode plate and a lower electrode plate along the thickness direction (z direction in the figure), wherein the upper electrode plate may be located between the first surface 21 a of the LCD module 21 and the transparent cover plate 22 Between the second surfaces 22 b , the lower electrode plate may be located between the second surface 21 b of the LCD module 21 and the first surface 20 a of the light source component 20 .

For example, one side of the lower electrode plate of the electrode 25 can be attached to the second surface 21b of the LCD module 21, and the light source component 20 can be attached to the other side of the lower electrode plate through optical glue.

Compared with the existing LCD screen, the image capturing device 2 of this embodiment eliminates the air gap, so that the incident light with a larger incident angle can also enter the LCD module 21 smoothly. Since the increase of the incident angle will cause the difference of the polarization state of the incident light in the LCD module 212 to increase, the solution in this embodiment can effectively reduce the difference of the polarization state by optimizing the electrode design, so that the difference in the polarization state of the incident light can be better in the screen. Internally, the total extinction of the light within the critical angle of total reflection is ensured, and it is avoided that the LCD module 21 cannot achieve total darkness due to the light passing through the LCD module 21 in a non-conducting state.

Specifically, in order to eliminate the influence of the dependence of the extinction of the polarizer on the angle on the image display and image acquisition effect, the image acquisition device 2 in this embodiment optimizes the electrode design so that the The electric field distribution in the liquid crystal layer 213 is adjusted in a targeted manner, so as to reduce the difference in phase deflection under different light paths to an acceptable range as much as possible.

The solution of this embodiment utilizes the principle that the change of the refractive index of the liquid crystal has a certain relationship with the electric field strength there, and the electric field strength can be adjusted through electrode design. Thus, the electrode 25 can apply a voltage to the liquid crystal layer 213 to adjust the refractive index of the liquid crystal layer 213 .

Specifically, liquid crystal is a material with birefringence, and the incident light will be decomposed into two orthogonal rays (hereinafter referred to as ordinary light and extraordinary light) after entering the liquid crystal layer 213, and the ordinary light and extraordinary light are in the liquid crystal layer. The refractive indices within 213 are different. The refractive index of the extraordinary light can vary with the voltage applied to the liquid crystal layer 213; the difference in the refractive indices of the ordinary light and the extraordinary light determines the difference in the polarization state of the incident light.

As the angle of incidence is larger, the difference in polarization states is larger. Therefore, in order to reduce the difference in the polarization state, in the solution of this embodiment, the electrode 25 applies different voltages to different regions of the liquid crystal layer 213, so that the adjustment amount of the refractive index in the region where the incident light with a larger incident angle is incident is more big. Wherein, the different regions may refer to different regions along a plane perpendicular to the thickness direction (the z direction in the figure).

That is, since the polarization state difference of a region with a larger incident angle is larger, the adjustment amount of the refractive index of the region needs to be increased accordingly, so that the polarization state difference of the region can be reduced to a tolerable error range.

In a specific implementation, for the same region of the liquid crystal layer 213, the voltage applied by the electrode to the region varies with the incident angle of incident light incident on the region.

For example, the light source part 20 is composed of point light sources arranged in an array. When the point light sources and the corresponding sensor parts 23 are turned on row by row to perform the image capturing operation, the incident angle of the incident light incident on the same area increases with It varies depending on the position of the lit light source. Therefore, according to the incident angle of the incident light incident on a specific area, the electrode 25 adjusts the voltage applied to the specific area in a targeted manner, so that when the incident angle of the incident light incident on the specific area is small, the refraction of the specific area will be reduced. The adjustment amount of the refractive index of the specific area is small; as the incident angle of the specific area increases, the adjustment amount of the refractive index of the specific area gradually increases.

In a typical application scenario, referring to FIG. 2 , taking the incident light emitted by the light source P as an example, for the area of the liquid crystal layer 213 located directly above the light source P along the thickness direction (the z direction in the figure), the incident light emitted by the light source P The incident angle in this area is small; for the area of the liquid crystal layer 213 except the area directly above the light source P, the closer to the edge of the liquid crystal layer 213, the larger the incident angle of the incident light emitted by the light source P in the corresponding area.

Correspondingly, when the electrode 25 applies a voltage to the liquid crystal layer 213, the voltage applied to the area of the liquid crystal layer 213 directly above the light source P is different from the voltage applied to other areas of the liquid crystal layer 213, and the voltage applied to the area of the liquid crystal layer 213 is adjusted to different degrees. The refractive index of the region of the liquid crystal layer 213 directly above and the refractive index of other regions of the liquid crystal layer 213 .

For example, the reduction in the refractive index of the region of the liquid crystal layer 213 directly above the light source P may be smaller than the reduction in the refractive index of other regions of the liquid crystal layer 213, so that the incident light emitted by the light source P entering other regions of the liquid crystal layer 213 The high angle path enhancement of the light is compensated by the refractive index drop in this region to achieve a sufficiently small phase shift from the small angle incident light emitted by the light source P into the region of the liquid crystal layer 213 directly above it.

In a specific implementation, for any region of the liquid crystal layer 213, when the dielectric anisotropy (dielectrical anisotropy) of the liquid crystal material filled in the region is greater than zero, the voltage applied by the electrode 25 to the region increases with the incident on the region. It increases with the increase of the incident angle of the incident light in the area.

For example, liquid crystal material 5CB and liquid crystal material E7 are two commonly used liquid crystal materials with dielectric anisotropy greater than zero.

In a variant, when the dielectric anisotropy of the liquid crystal material filled in the region is less than zero, the voltage applied by the electrode 25 to the region decreases as the angle of incidence of incident light incident on the region increases.

For example, the liquid crystal material MBBA belongs to a commonly used liquid crystal material whose dielectric anisotropy is less than zero.

From the above, it is possible to achieve extinction of light with an incident angle within the critical angle of total reflection, avoiding the problem of light leakage when the light path of the LCD module 21 is not turned on, and affecting the imaging effect during image acquisition or image display.

When the incident angle exceeds the critical angle of total reflection, the incident light is naturally in a waveguide state and cannot escape the display (waveguide) surface, that is, the light-transmitting cover plate 22, so that it will not be observed, thus achieving extinction.

In other words, the light in this waveguide condition is the light detected as a fingerprint in this embodiment. For example, the incident light emitted by the light source P in FIG. 2 with an incident angle greater than the critical angle of total reflection will be totally reflected at point D of the transparent cover plate 22, and the image formed by the total reflection of the transparent cover plate 22 can be reflected by the transparent cover plate 22. The sensor part 23 captures, thereby realizing an image capture operation based on the principle of total reflection.

In a specific implementation, the total reflection critical angle may be about 42°.

In a specific implementation, the sensor component 23 may be integrated into the upper glass plate 212 .

For example, the sensor part 23 may be integrated on the side of the upper glass plate 212 facing the color filter 211.

In a variant, the sensor component 23 may be integrated on the side of the color filter 211 facing the upper glass plate 212 .

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

For example, the display panel can be selected from a liquid crystal display screen, an active-matrix organic light-emitting diode display screen, and a micro-LED display screen.

In a specific implementation, the light-transmitting cover plate 22 may be made of glass material.

Specifically, the transparent cover plate 22 can integrate protection and touch functions.

When the image capturing device 2 is applied to fingerprint recognition under the optical screen, the first surface 22a of the light-transmitting cover plate 22 can be used to contact fingerprints.

In a specific implementation, an optical adhesive layer 24 may be filled between the transparent cover plate 22 and the LCD module 21 . For example, the first surface 21a of the LCD module 21 can be adhered to the second surface 22b of the transparent cover plate 22 through optical adhesive.

From the above, with the solution of this embodiment, image acquisition based on the principle of total reflection can be realized under the LCD screen, the imaging effect is optimized, and the imaging clarity is improved. Specifically, the LCD module 21 is attached to the light source component 20, so that the light source component 20 is packaged in the image acquisition device 2 as a component integrated with the LCD module 21, so as to eliminate the LCD module 21 and the light source. The influence of the air gap between the components 20 on the imaging result prevents the incident light emitted by the light source component 20 from being totally reflected when it reaches the LCD module 21, so as to ensure that the incident light with a large angle can smoothly enter the LCD module 21, and then in the transparent module 21. Total reflection occurs at the light cover plate 22, so that image acquisition based on the principle of total reflection becomes possible.

FIG. 3 is a schematic diagram of an image acquisition device according to a second embodiment of the present invention. Only the differences between the image acquisition device 3 and the image acquisition device 2 shown in FIG. 2 are mainly described here.

In this embodiment, the main difference from the image capturing device 2 shown in FIG. 2 is that the sensor component 23 can be integrated into the lower glass plate 214 .

For example, the sensor part 23 may be integrated on the side of the lower glass plate 214 facing the liquid crystal layer 213 .

In a specific implementation, the lower glass plate 214 may be integrated with a thin film transistor (Thin Film Transistor, TFT for short). Further, the photodiode and the TFT may be distributed on the surface of the lower glass plate 214 in parallel.

Compared with the image acquisition device 3 shown in FIG. 3 , the image acquisition device 2 shown in FIG. 2 has a higher light transmittance of the sensor part 23 disposed on the upper glass plate 212 , which is beneficial to obtain clear imaging. Specifically, the closer the sensor part 23 is to the light-transmitting cover plate 22 , the shorter the return distance of the total reflection light carrying the fingerprint information, so that the light absorption efficiency is higher.

On the other hand, since the photodiode needs to occupy an area, when the sensor part 23 is arranged on the upper glass plate 212, the photodiode and the TFT on the lower glass plate 214 can be in the thickness direction. Aligned to increase light transmittance.

Compared with the image acquisition device 2 shown in FIG. 2 , the image acquisition device 3 shown in FIG. 3 is easier to implement in the manufacturing process, and the manufacturing process complexity is low.

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

In this embodiment, the main difference from the image capture device 2 shown in FIG. 2 is that the sensor component 23 can be disposed between the light-transmitting cover plate 22 and the LCD module 21 .

For example, the sensor component 23 may be disposed between the second surface 22b of the transparent cover plate 22 and the first surface 21a of the LCD module 21, and the space between the transparent cover plate 22 and the LCD module 21 Other voids can still be filled with optical glue.

In a specific implementation, the sensor component 23 may be disposed close to the second surface 22b of the light-transmitting cover plate 22 to obtain higher light transmittance.

Alternatively, the sensor component 23 can also be disposed close to the first surface 21 a of the LCD module 21 .

In a specific implementation, the sensor part 23 can be made of a transparent material, so as to avoid affecting the image display effect of the display panel in the non-image acquisition stage.

In a specific implementation, the display and sensing may be time-shared. That is, when the image is displayed, no voltage is applied to the sensor part 23, and the image of the light source part 20 can be displayed through the light-transmitting cover plate 22 without being affected by the sensor part 23. Occlusion; during image acquisition, the sensor component 23 is applied with a voltage to acquire the image of the object to be acquired.

Therefore, by disposing the sensor part 23 outside, in addition to integrating the light source part 20 , the total reflected light can be captured without changing other manufacturing processes of the LCD module 21 , which is beneficial to reduce the complexity of the manufacturing process.

The image acquisition device 2 to the image acquisition device 4 in this embodiment can be applied to electronic devices such as mobile phones, smart bracelets, and wristwatches.

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. Therefore, the protection scope of the present invention should be based on the scope defined by the claims.

1: LCD fingerprint sensor 10: Translucent cover 11: LCD stacking 110: Upper polarizer 111: Color filter 112: Upper glass plate 113: liquid crystal layer 114: Lower glass plate 115: Lower polarizer 12: Backlight module 13: Air gap 14: Optical Adhesive Layer 15: Sensor parts 2~4: Image acquisition device 20: Light source parts 20a: The first side of the light source part 20b: The second side of the light source part 21: LCD module 21a: The first side of the LCD module 21b: Second side of LCD module 210: Upper polarizer 211: color filter 212: Upper glass plate 213: liquid crystal layer 214: Lower glass plate 215: Lower polarizer 22: Translucent cover 22a: The first side of the transparent cover 22b: The second side of the transparent cover 23: Sensor parts 24: Optical Adhesive Layer 25: Electrodes A: point B: point D: point O: light source P: light source z: direction

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein: 1 is a schematic diagram of a prior art LCD fingerprint sensor; FIG. 2 is a schematic diagram of an image acquisition device according to the first embodiment of the present invention; 3 is a schematic diagram of an image acquisition device according to a second embodiment of the present invention; and FIG. 4 is a schematic diagram of an image acquisition device according to a third embodiment of the present invention.

2: Image acquisition device

20: Light source parts

20a: The first side of the light source part

20b: The second side of the light source part

21: LCD module

21a: The first side of the LCD module

21b: Second side of LCD module

210: Upper polarizer

211: color filter

212: Upper glass plate

213: liquid crystal layer

214: Lower glass plate

215: Lower polarizer

22: Translucent cover

22a: The first side of the transparent cover

22b: The second side of the transparent cover

23: Sensor parts

24: Optical Adhesive Layer

25: Electrodes

D: point

P: light source

z: direction

Claims (10)

An image acquisition device, comprising: a light source part, the light source part has opposite first and second surfaces along the thickness direction; an LCD module, the LCD module has an opposite first surface and a second surface along the thickness direction, and the second surface of the LCD module is attached to the first surface of the light source component; 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 contacting the object to be collected, and the first surface of the light-transmitting cover plate is suitable for contacting the object to be collected. The two sides are disposed toward the first side of the LCD module; and a sensor component for collecting incident light reflected from the light-transmitting cover plate. The image acquisition device according to claim 1, wherein an adhesive material is filled between the second surface of the LCD module and the first surface of the light source component. The image acquisition device according to claim 1, further comprising: An electrode is coupled to the LCD module, and the electrode is configured to control the difference between the polarization states of incident light with different incident angles in the LCD module within a tolerable error range. The image acquisition device of claim 3, wherein the LCD module comprises a liquid crystal layer, and the electrode applies a voltage to the liquid crystal layer to adjust the refractive index of the liquid crystal layer. The image acquisition device according to claim 4, wherein the electrode applies a voltage to the liquid crystal layer to adjust the refractive index of the liquid crystal layer means that the electrode applies different voltages to different regions of the liquid crystal layer to make the incident angle The larger the amount of adjustment of the refractive index in the region where the incident light is incident, the larger. The image acquisition device according to claim 4, wherein, for the same area of the liquid crystal layer, the voltage applied by the electrode to the area varies with the incident angle of incident light incident on the area. The image acquisition device according to claim 6, wherein when the dielectric anisotropy of the liquid crystal material filled in the region is greater than zero, the voltage applied by the electrode to the region varies with the incident angle of incident light incident on the region When the dielectric anisotropy of the liquid crystal material filled in the area is less than zero, the voltage applied by the electrode to the area decreases with the increase of the incident angle of the incident light incident on the area. The image acquisition device according to claim 1, wherein the LCD module comprises, An upper polarizer, a color filter, an upper light-transmitting plate, a liquid crystal layer, a lower light-transmitting plate, and a lower polarizer are sequentially arranged along a first direction, wherein the first direction is the first surface of the LCD module Point in the direction of the second side. The image acquisition device according to claim 8, wherein the sensor component is integrated in the upper light-transmitting plate or the lower light-transmitting plate. The image acquisition device according to claim 1, wherein the sensor component is disposed between the light-transmitting cover plate and the LCD module.

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