CN111242013B

CN111242013B - Display and input device

Info

Publication number: CN111242013B
Application number: CN202010026423.6A
Authority: CN
Inventors: 黄忠守
Original assignee: Shanghai Oxi Technology Co Ltd
Current assignee: Shanghai Oxi Technology Co Ltd
Priority date: 2020-01-10
Filing date: 2020-01-10
Publication date: 2023-05-16
Anticipated expiration: 2040-01-10
Also published as: CN111242013A

Abstract

The embodiment of the invention discloses a display and input device, which comprises: a display panel comprising a display array of a plurality of display pixels, the display pixels comprising n sub-pixels for displaying different colors; the backlight module comprises LED lamp source components which emit n different color spectrums; a fingerprint sensing module, which comprises a sensing array composed of a plurality of photosensitive pixels; in a frame image display period, the LEDs of each color in the light source assembly are alternately lightened m times; in the display period of one frame of image, the lighting time sequences of the fingerprint sensing module and the lamp source assembly are synchronous, at least n fingerprint images with different colors are collected and transmitted to an external circuit for synthesizing a color fingerprint image or a multispectral fingerprint image. The embodiment of the invention can obtain the high-sensitivity color fingerprint image.

Description

Display and input device

Technical Field

Embodiments of the present invention relate to display technologies, and in particular, to a display and input device.

Background

With the expansion of the application market of mobile terminals with integrated fingerprint detectors in display screens, users have put forward higher, more specific or finer technical requirements on the performance of the fingerprint detector, such as determining whether a finger is true or false.

At present, an effective way for a fingerprint detector to identify a true finger or a false finger is to collect a dynamic series of color fingerprint images, extract dynamic information of blood diffusion in capillaries on the lower surface of the skin caused by finger pressing, and judge the true finger or the false finger. Therefore, the key to the fingerprint detector to identify a genuine finger is to acquire a plurality of color fingerprint images of high quality in a short time.

However, the existing fingerprint detector collects color fingerprint images by covering a filter sheet capable of only passing monochromatic light, so that the intensity of detectable light is reduced by as much as 70%. For a display device provided with a display color filter, the sub-pixels of the display array and the fingerprint detector may be aligned up and down, and the display color filter may be multiplexed into a single color filter required by the fingerprint detector, so that the single color filter covering the fingerprint detector may be omitted, but the manufacturing process of the structure is complicated, and even if the alignment is possible, the reflected light of the finger may be laterally diffused in the glass substrate of the thicker color filter through multiple reflection and refraction, resulting in color mixing of the color image reaching the fingerprint detector. Finally, the quality of the color fingerprint image detected by the fingerprint detector is affected, so that the judgment result is affected, and even various misjudgment results are caused.

Disclosure of Invention

The embodiment of the invention provides a display and input device for improving the quality of a fingerprint image detected by a fingerprint detector.

The embodiment of the invention provides a display and input device, which comprises:

a display panel comprising a display array of a plurality of display pixels, the display pixels comprising n sub-pixels displaying different colors, n being greater than or equal to 2;

the backlight module is covered on the display panel and used for providing illumination, and comprises Light Emitting Diode (LED) lamp source components for emitting n different color spectrums;

a fingerprint sensing module which is arranged on one side of the display panel far from the backlight module or one side close to the backlight module and is used for sensing fingerprint images, wherein the fingerprint sensing module comprises a sensing array formed by a plurality of photosensitive pixels;

the LEDs of each color in the light source assembly are alternately lighted m times during a frame image display period, where m is greater than or equal to 1;

and in the image display period of one frame, the fingerprint sensing module and the lighting time sequence of the lamp source assembly are synchronous, at least n fingerprint images with different colors are collected and transmitted to an external circuit for synthesizing a color fingerprint image or a multispectral fingerprint image.

In the embodiment of the invention, in a frame of image display period, the LEDs of each color in the light source assembly are alternately lightened m times, and the lighting time sequences of the fingerprint sensing module and the light source assembly are synchronous, so that on the basis of not affecting the display effect, the fingerprint sensing module can acquire a plurality of monochromatic spectrum fingerprint images in the frame of image display period, an independent optical filter is not required to be added to a photosensitive pixel, and the display pixel of the display array and the photosensitive pixel of the sensing array are not required to be aligned to multiplex the optical filter of the display pixel, thereby improving the light intensity which can be collected by the photosensitive pixel and reducing the manufacturing difficulty of the process. The LEDs of each color in the light source component are alternately lightened m times in one frame of image display period, and when a reflection signal of a monochromatic spectrum propagates in a glass substrate of a thicker display panel or a glass cover plate on the surface, even if light rays caused by multiple reflection and refraction are laterally diffused, the reflection signal reaches a sensing array and reaches photoelectric signals of the same color spectrum, and color mixing does not occur, so that a color fingerprint image with high sensitivity can be obtained.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, a brief description will be given below of the drawings required for the embodiments or the description of the prior art, and it is obvious that although the drawings in the following description are specific embodiments of the present invention, it is not to be construed that these should be construed as falling within the scope of the claims of the present invention, for the device structure, driving method and manufacturing method, which are disclosed and suggested by the various embodiments of the present invention, to extend and extend to other structures and drawings.

FIG. 1 is a schematic diagram of a display and input device provided in an embodiment of the present invention;

FIG. 2 is a partial schematic view of a fingerprint recognition module of the display and input device of FIG. 1;

FIG. 3 is a cross-sectional view provided by another embodiment;

FIG. 4 is a cross-sectional view taken along line A-A' of FIG. 1;

FIG. 5 is a driving timing sequence of a backlight module and a fingerprint sensing module of the display and input device shown in FIG. 1;

FIG. 6 is a driving timing diagram of a backlight module and a fingerprint sensor module of the display and input device shown in FIG. 1.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described by means of implementation examples with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the basic concepts disclosed and suggested by the embodiments of the present invention are within the scope of the present invention.

Referring to fig. 1 to 4, a schematic diagram of a display and input device according to an embodiment of the present invention is provided, in which fig. 1 is a schematic plan view of the display and input device, fig. 2 is a schematic partial view of a fingerprint recognition module, fig. 3 is a cross-sectional view of another embodiment, and fig. 4 is a cross-sectional view taken along A-A' in fig. 1. The display and input device provided in this embodiment includes: a display panel 1, wherein the display panel 1 comprises a display array 1a composed of a plurality of display pixels 1b, the display pixels 1b comprise n sub-pixels 1c for displaying different colors, and n is greater than or equal to 2; a backlight module 3 covering the display panel 1 for providing illumination, wherein the backlight module 3 comprises a Light Emitting Diode (LED) lamp source assembly 3a for emitting n different color spectrums; a fingerprint sensing module 2 disposed on one side of the display panel 1 far from the backlight module 3 or on one side close to the backlight module 3 for sensing fingerprint images, wherein the fingerprint sensing module 2 comprises a sensing array 2a composed of a plurality of photosensitive pixels 2 b; in one frame image display period, the LEDs of each color in the light source assembly 3a are alternately lighted m times, where m is greater than or equal to 1; in one frame of image display period, the lighting timing of the fingerprint sensing module 2 and the light source assembly 3a are synchronized, and at least n fingerprint images of different colors are acquired and transmitted to an external circuit (not shown) for synthesizing a color fingerprint image or a multispectral fingerprint image. The optional display and input device is a liquid crystal display device. It should be noted that, the LED lamp capable of emitting infrared IR is also shown in the light source assembly of fig. 3 and 4, and although the display pixel does not include a subpixel capable of transmitting IR exclusively, it is understood that the R, G, and B color filters commonly used can transmit IR light to a certain extent, so that in practical application, it is not necessary to provide an IR-transmitting subpixel exclusively. The display pixel also comprises a W sub-pixel which transmits white light, and can also transmit infrared light.

In the present embodiment, the display panel 1 has a display function. The display panel 1 comprises a display array 1a comprising a plurality of display pixels 1b, the number of the display pixels 1b is related to the resolution of the display panel 1, the resolution required by different products is different, and the number of the display pixels 1b in the display array 1a is correspondingly changed, wherein the plurality is an integer with the number exceeding 2, i.e. the display panel 1 comprises a display array 1a comprising more than two display pixels 1 b. In the display phase, each display pixel 1b within the display array 1a displays normal image content to realize a display function, and the display process and principle of the display phase are not described here.

The display pixel 1b includes n kinds of subpixels 1c displaying different colors. The backlight module 3 provides backlight, the display panel 1 does not emit light, and the backlight light is filtered into light with different colors by the display panel 1, so that the sub-pixel 1c is substantially a color filtering area covered by the color filter in the display panel 1. Optionally, n=3, the display panel 1 includes a red R filter, a green G filter, and a blue B filter, the backlight light passing through the R filter is red light, the backlight light passing through the G filter is green light, and the backlight light passing through the B filter is blue light. In other embodiments, the display pixels may also include two or more different color sub-pixels, for example, the display pixels may include a yellow color sub-pixel, or others, the color type of the sub-pixels in the display pixels and the number of sub-pixels of each color are not limited in the present invention.

In this embodiment, the backlight module 3 is covered on the display panel 1 to provide illumination, specifically, the backlight module 3 is covered on the side of the display panel 1 facing away from the touch surface. The backlight module 3 includes Light Emitting Diode (LED) lamp assemblies 3a emitting n different color spectrums. Optionally n=3, the light source assembly 3a comprises three LEDs emitting red light R, green light G, blue light B. The backlight module 3 can control the light source assembly 3a to emit light with different colors according to different display modes, for example, when R is independently turned on, red spectrum is emitted, RGB is turned on simultaneously or sequentially and alternately, and if the respective brightness ratio is a certain occasion, the light rays show white spectrum as a result of integration in space or time. In any case, red light passes through the R filter in the display panel 1, green light passes through the G filter in the display panel 1, and blue light passes through the B filter in the display panel 1.

In this embodiment, a fingerprint sensing module 2 is disposed on one side of the display panel 1 far from the backlight module 3 or on one side close to the backlight module 3 for sensing fingerprint images, the fingerprint sensing module 2 comprises a sensing array 2a composed of a plurality of photosensitive pixels 2b, wherein the plurality is an integer with an index exceeding 2, i.e. the fingerprint sensing module 2 comprises a sensing array 2a composed of more than two photosensitive pixels 2 b. When a finger is pressed against the glass cover plate 4, the light emitted by the display will illuminate the fingerprint. The light reflected by the raised parts of the fingerprint is weaker, and the light reflected by the concave parts is stronger, so that an optical image corresponding to the bright and dark fringes of the fingerprint is formed. After the photoelectric conversion period of each photosensitive pixel 2b is turned on, photons reflected from the finger print are converted into photo-generated charges. The photosensitive pixels 2b continuously accumulate photoelectric signals before being refreshed, the photoelectric signals reflect the intensity of the reflected signals of the finger surface fingerprints, and the image synthesized by the intensity changes of the photoelectric signals of the plurality of photosensitive pixels 2b in the sensing array 2a is the image of the finger surface fingerprints. If the sensing array completely covers the entire display array, the display and input device is capable of achieving full display area fingerprinting or simply full screen fingerprinting.

In this embodiment, when a user inputs a fingerprint, the fingerprint recognition module 2 is started and enters a fingerprint sensing stage.

Referring to fig. 5, the driving timing of the backlight module and the fingerprint sensing module is shown, wherein Imaging & Data Aquisitin and hold is the driving timing of the fingerprint sensing module, including Imaging, data acquisition and data retention, and LED intensity is the driving timing of the backlight module. The driving principle is as follows: in the fingerprint sensing stage, R, G and B in the backlight module are sequentially lightened in a display period of each frame of image in a shorter pulse width. When the lighting frequency of the R, G and B three-color light pulses is higher than the limit which can be distinguished by human eyes, the human eyes cannot detect that three colors of light flicker in a picture. If the ratio of the output light amounts of the R, G and B three-color LEDs is proper, the human eyes can only perceive white light. Although the spectrum color emitted by the backlight module is continuously switched at a high speed, the average spectrum color is still equivalent to white backlight, and the intensity and the color of the output light of each pixel can be modulated by modulating the transmittance of each sub-pixel of R, G and B. Then, the frame period of the high-speed acquisition and processing image signals of the fingerprint sensing module is synchronous with the light pulse of the backlight module, so that the monochromatic fingerprint image reflected by the monochromatic light from the skin surface of the finger can be acquired. According to the monochromatic fingerprint image, the image processing module of the rear-end external circuit can obtain a full-color fingerprint image through the image fusion and processing method. When IR LEDs in the backlight module are used, images of blood vessels or blood flow, which represent near infrared of subcutaneous biological features, can also be acquired.

In the fingerprint sensing stage, the backlight module 3 is used as a surface light source for illuminating fingerprints; the fingerprint sensing phase comprises at least one frame image display period. In one frame of image display period, the LEDs of each color in the light source assembly 3a are alternately turned on m times, where m is greater than or equal to 1, and then in each frame of image display period, the LEDs of one color blink m times, and the n-color LED lamps blink n times in total.

Taking m=10 as an example, in one frame image display period, the red LEDs, green LEDs and blue LEDs in the light source assembly 3a are alternately lighted 10 times, and the spectral colors emitted from the light source assembly 3a are switched 30 times in one frame image display period. It will be appreciated that m=10 is only an example here, and is not limited thereto, and m may be an integer from 1 to 100.

The lighting timings of the fingerprint sensing module 2 and the light source assembly 3a may be synchronized during one frame image display period, and at least n fingerprint images of different colors are acquired and transmitted to an external circuit (not shown) for synthesizing a color fingerprint image or a multispectral fingerprint image.

In one frame image display period, the LEDs of each color in the light source assembly 3a are alternately lit m times, where m is greater than or equal to 1. The frame rate of the optional display panel 1 is 30Hz to 240Hz, and when light changes periodically with a frequency of 30Hz or more, the response time constant is approximately 0.1 seconds, so that the human eye cannot perceive flickering of light, but only light with uniform brightness is perceived. Based on this, in one frame of image display period, the LEDs of each color in the light source assembly 3a are alternately turned on m times, that is, the light rays of n colors are alternately switched at high speed, so that the human eye cannot observe the switching of the light rays of n colors, only the picture output of the light rays synthesized by n colors can be observed, and the display effect of the picture observed by the human eye cannot be affected. At this time, the color or tone of the screen is determined by the energy ratio of the pulsed light of the LED, the transmittance of each pixel, and the transmission spectrum of the color film of the display array, which are multiplied by each other.

The monochromatic spectrums of R, G and B are sequentially irradiated to finger fingerprints and then reflected back to enter the fingerprint sensing module 2, the acquisition period of the fingerprint sensing module 2 is synchronous with the lighting period of the backlight module 3, and then the fingerprint sensing module 3 finishes the accumulation of photoelectric signals of sensing pixels and immediately samples and holds the photoelectric signals before the color of the reflection spectrum is unchanged, so that a plurality of monochromatic fingerprint images of red, green and blue can be sequentially obtained. If the backlight module 3 further comprises LEDs capable of emitting infrared light IR among the three-color LEDs of R, G and B, a plurality of monochromatic light fingerprint images and infrared fingerprint images of red, green, blue and infrared can be obtained sequentially. The external circuit synthesizes a plurality of monochromatic light fingerprint images to obtain a color fingerprint image.

In this embodiment, in a frame of image display period, the LEDs of each color in the light source assembly are alternately turned on m times, and the lighting timings of the fingerprint sensing module and the light source assembly are synchronous, so that on the basis that the display effect is not affected, the fingerprint sensing module can collect multiple monochromatic spectrum fingerprint images in a frame of image display period, no independent optical filters need to be added to photosensitive pixels, and no optical filters for multiplexing the display pixels of the display array and the photosensitive pixels of the sensing array need to be aligned, so that the light intensity that the photosensitive pixels can collect is improved, and the manufacturing difficulty of the process is reduced. The LEDs of each color in the light source component in one frame of image display period are alternately lightened m times, and the light rays of a monochromatic spectrum are transversely diffused in the glass cover plate of the display panel or the glass cover plate on the surface by multiple reflection and refraction to reach the photoelectric signal of the sensing array or a single color spectrum, so that color mixing can not occur. Thus, fingerprint image acquisition with high image sensitivity and high resolution is realized, and fingerprint image quality is improved. The external circuit synthesizes the fingerprint images with high image sensitivity and high resolution, so that accurate judgment of the true finger and the false finger can be realized, and the judgment accuracy is improved.

The external circuit comprises an image processing circuit, the image processing circuit synthesizes the obtained monochromatic images with different colors, a colorful high-resolution fingerprint image can be obtained, accurate judgment of the true finger and the false finger can be realized, and the judgment accuracy is improved. For human eyes, the time response speed is about 0.1 second, and when the flicker frequency of the LED lamp source is higher than 30Hz, the flicker of a picture and the switching of colors are basically not felt. The refresh frequency of a color screen of a display such as a liquid crystal is usually 30Hz or more. In the display period of each frame of Color image, at least red, green and blue LED light sources are respectively lightened at least once, the comprehensive effect is the same as that of using a white backlight source, the driving mode is not changed, and the phenomenon of Color breaking in the FCS (Field Color Sequential) working mode is avoided.

Monochrome or so-called black-and-white image sensors, such as CCD (Charge Coupling Device) or CIS (CMOS Imaging Sensor), using silicon semiconductors as photosensitive devices and signal transmission devices, and employing a high-speed frame sensing mode, can acquire monochrome images at frame rates higher than 90Hz, and these image sensors do not require the use of color filters, so that the sensitivity is improved by at least three times as compared to image sensors using color filters. In the process of color fingerprint detection, a high-speed dynamic image of rapid blood diffusion in a subcutaneous capillary vessel of a finger can be acquired, so that the pressing of a true fingerprint and a false fingerprint can be accurately judged.

In some applications, a color image sensor with a color filter may be directly used, so that synchronization with a high-speed flickering LED light source is unnecessary, each frame of color picture may be integrated for a long time, so that a high signal-to-noise ratio is obtained, and the driving frequency may be relatively low, which may not obtain a high-speed color picture, but may be valuable in some applications. Especially when several monochromatic LED light sources are used, the brightness of each LED light source can be independently controlled, so that after the color films of the display screen and the image sensor are manufactured, the color saturation of the images of the display screen and the images of the fingerprint sensor can be adjusted at will in real time.

Optionally, referring to fig. 3 and 4, the light source assembly 3a further comprises an LED emitting infrared spectrum IR. The R, G, B and IR four sub-pixels of the lamp source assembly 3a are sequentially lightened in time through an external circuit, the acquisition frequency of the fingerprint sensing module 2 is completely synchronous with the R, G, B, IR lighting frequency, red, green, blue and infrared monochromatic spectrum fingerprint images can be sequentially acquired in time, at least one color fingerprint image is finally synthesized in the external circuit according to the requirement, or multispectral images are obtained through an image fusion method, or mutual operation is carried out on images with different colors including infrared, so that more valuable static and dynamic information reflecting biological characteristics is extracted.

The infrared light emitted by the sub-pixels emitting infrared spectrum can enter the finger and be reflected by blood components in the finger, so that an external circuit can detect the diffusion dynamic information of blood in capillaries under the skin of the finger according to the infrared fingerprint image, and the accuracy of further judging whether the finger is true or false is improved. Specifically, near infrared reflected light of a finger carries important information of hemoglobin in a capillary vessel, and absorption of oxyhemoglobin and deoxyhemoglobin to near infrared light is different, so that oxygen content in the blood vessel can be judged by detecting a near infrared image reflected by the skin of the finger, and even partial biological conditions can be interpreted, so that color information of the finger and information of blood content in the capillary vessel can be obtained, and the finger can be judged to be true or false, wherein a fingerprint sensing module collects a series of color fingerprint images, and the diffusion process of blood in the capillary vessel in the process that the finger is pressed on a display screen can be calculated, so that the possibility of spoofing a fingerprint image detector by a fake finger is fundamentally avoided.

Optionally, the sensor array shown with reference to fig. 3 covers a side of the display panel 1 away from the backlight module 3. The display and input device further comprises a glass cover plate 4, wherein the fingerprint sensing module 2 integrated with the sensing array is positioned on the glass cover plate 4, and the fingerprint sensing module 2 and the display panel 1 are positioned on the same side of the glass cover plate 4. The light emitted by the backlight module 3 illuminates the fingerprint, and the fingerprint reflected light enters the sensing array of the fingerprint sensing module 2 through the glass cover plate 4.

Optionally, the sensor array shown with reference to fig. 4 covers a side of the backlight module 3 remote from the display array. I.e. the fingerprint sensing module 2 is placed on the side of the backlight module 3 remote from the display panel 1. The light emitted by the backlight module 3 illuminates the fingerprint, and the fingerprint reflected light enters the sensing array of the fingerprint sensing module 2 through the display panel 1. Based on this, the optional backlight module 3 further includes a light guiding layer 3c, where the light guiding layer 3c is provided with a plurality of clear apertures, and the light reflected by the finger surface passes through the clear apertures to reach the sensing array. The light guiding layer 3c is configured to uniformly scatter the LED light emitted from the light source assembly 3a and emit the LED light to the display panel 1. The optional light guiding layer 3c comprises a light guiding plate and a light reflecting layer (or grid layer), and a clear aperture is arranged at the bottom of the light guiding plate, i.e. on the light reflecting layer containing uniformly scattered incident LED light.

In this embodiment, the light source assembly 3a of the backlight module 3 includes at least two LED point light sources with different colors, the light source assembly 3a can be placed on the side surface of the light guiding layer 3c, and after the light emitted by the backlight module 3 illuminates the finger fingerprint and is reflected, the light needs to pass through the light guiding layer 3c to enter the sensing array of the fingerprint sensing module 2, based on this, a plurality of clear apertures are provided in the light guiding layer 3c, so that the reflected light of the finger fingerprint can reach the sensing array arranged below the display panel 1, and the collimation effect is also achieved.

In other embodiments, the point light sources of the optional light source assembly form a two-dimensional matrix and are arranged right below the display panel, and the light emitted by the point light sources is scattered and refracted to become a uniform area light source, so that the fingerprint is illuminated or displayed. In addition, the monochromatic light emitted by the backlight module for illuminating the fingerprint can illuminate the fingerprint through the color filter of the display panel, and can illuminate the fingerprint through a side surface or other light paths instead of the display panel, and the invention is not particularly limited.

Optionally, the product of the refresh frequency and m for each frame of image of the display array is greater than 90Hz.

In this embodiment, the fingerprint sensing module, the backlight module and the display panel are integrated in the display and input device, and in one frame of image display period, the LEDs of each color in the light source assembly are alternately turned on m times, and the light source assembly includes the LEDs of n colors, so that the number of flicker times of the light source assembly in one frame of image display period is n times m times, based on which the flicker frequency of the light source assembly is equal to the frame frequency of the display array multiplied by m times n. The product of the refresh frequency and m of each frame of image of the display array is larger than 90Hz, the lower limit value of the flicker frequency of the light source assembly can be limited to 90n, the light source assembly can be ensured to have higher flicker times in a frame of image display period, further, the flicker of the light source is prevented from being perceived by human eyes, and the display effect is improved.

The frame frequency of the selectable display panel is 60 Hz-120 Hz, and the image acquisition frame frequency of the fingerprint sensing module is 120 Hz-360 Hz.

In this embodiment, the frame frequency of the display panel is 60 Hz-120 Hz, and the image acquisition frame frequency of the fingerprint sensing module may be an integer multiple of the frame frequency of the display panel, so that each monochromatic light fingerprint image can be accurately acquired. The image acquisition frame frequency of the optional fingerprint sensing module is 90 Hz-180 Hz, and even reaches a high-speed frame frequency of 360Hz to operate. The image acquisition frame frequency of the fingerprint sensing module is equal to the flicker frame frequency of the light source assembly, so that the light source assembly can be ensured to have higher flicker times in one frame of image display period, and the human eyes are prevented from perceiving the flicker of the light source. And the LED pulse light which is lighted in a high-speed circulation way is emitted through the display panel, can be blurred by the slow time response of human eyes, cannot be detected to switch the color at a high speed, and ensures the display effect.

Optionally, the fingerprint sensing stage shown with reference to fig. 6 includes at least one frame of image display period and at least one frame of background image acquisition period; in the background image acquisition period, the backlight module is not lightened, and the fingerprint sensing module acquires a reference background picture and transmits the reference background picture to an external circuit for eliminating background noise in the fingerprint image. Wherein dark is the non-lighting interval of the backlight module. Ambient light, especially in outdoor environments where sunlight is relatively intense, can enter the space around the finger through refraction and scattering pathways and impinge on the sensing array, affecting the contrast of the detected fingerprint image.

In this embodiment, based on the mode of lighting the LEDs in the pulse manner of the backlight module, a full black frame or black subframe that does not light any LEDs may be inserted into a series of gaps of high-speed light pulses, and the dark period that does not light any LEDs is used as a background image acquisition period, so that the backlight module is not lit. At this time, the light entering the sensing array is ambient stray light, such as solar light and indoor illumination. After the fingerprint sensing module collects a reference background picture and transmits the reference background picture to an external circuit, the reference background picture is a noise background image which is caused by the interference of pure ambient stray light on the sensor array. The external circuit subtracts the reference background picture from the fingerprint image, so that the background noise and the stray noise in the fingerprint image can be eliminated, the clear fingerprint image can be obtained, the definition, contrast and discrimination of the fingerprint image can be improved, and the weaker fingerprint image can be normally detected, so that the fingerprint identification capability and the external interference resistance capability of the fingerprint sensing module are improved.

With the display and input device described in any of the above embodiments, the backlight module controls the LEDs of each color to be alternately lit m times in one frame image display period. Based on this, the display and input device of the embodiment can actively adjust the brightness of the n colors of LEDs in the backlight module according to the color distribution of the picture to be displayed by the display panel, so that the light output by the backlight module is closer to the picture color of the display panel. For example, the images displayed by the display panel are mainly blue sky and white cloud, so that the brightness of the red LEDs in the backlight module can be reduced, the display effect of the display image is not affected, and the loss of light rays emitted by the red LEDs on the green and blue filters of the display panel can be reduced. The power consumption of the backlight module is reduced.

In addition, referring to fig. 3 and fig. 4, the display panel 1 of the embodiment of the present invention includes a touch panel 5, where the touch panel 5 can detect whether the display and input device is touched by a finger, so that the driving mode of the fingerprint sensing module 2 can be selectively turned on or off, and the display mode of the backlight module 3 can be selectively switched. Specifically, when the touch panel 5 detects that a finger touches, the fingerprint sensing module 2 can be started to enter a fingerprint sensing stage, and the display mode of the backlight module 3 is controlled to be that the LEDs with each color are alternately lightened in a pulse mode; the touch panel 5 detects that no finger is touched, and can turn off the fingerprint sensing module 2 to sleep, and also control the display mode of the backlight module to light up the LEDs of each color in a direct current manner. The power consumption of the display and input device is reduced.

Note that the above is only a preferred embodiment of the present invention and the technical principle applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, while the invention has been described in connection with the above embodiments, the invention is not limited to the embodiments, but may be embodied in many other equivalent forms without departing from the spirit or scope of the invention, which is set forth in the following claims.

Claims

1. A display and input device, comprising:

2. The display and input device of claim 1, wherein the product of the refresh frequency and m for each frame of image of the display array is greater than 90Hz.

3. The display and input device of claim 1, wherein the light source assembly further comprises an LED that emits in the infrared spectrum.

4. The display and input device of claim 1, wherein the light source assembly comprises three LEDs that emit red, green, and blue light.

5. The display and input device of claim 1, wherein the fingerprint sensing stage comprises at least one frame of image display period and at least one frame of background image acquisition period;

in the background image acquisition period, the backlight module is not lightened, and the fingerprint sensing module acquires a reference background picture and transmits the reference background picture to the external circuit so as to eliminate background noise in the fingerprint image.

6. The display and input device of claim 1, wherein the sensor array covers a side of the backlight module remote from the display array.

7. The display and input device of claim 6, wherein the backlight module further comprises a light guiding layer, the light guiding layer is provided with a plurality of clear apertures, and light reflected from the finger surface passes through the clear apertures to reach the sensing array.

8. The display and input device of claim 1, wherein the sensor array covers a side of the display panel remote from the backlight module.

9. The display and input device according to claim 1, wherein the frame frequency of the display panel is 60 Hz-120 Hz, and the image acquisition frame frequency of the fingerprint sensing module is 120 Hz-360 Hz.

10. The display and input device of claim 1, wherein the display and input device is a liquid crystal display device.