TW202102911A - Display device, operating method thereof and integrated control chip - Google Patents

Abstract

A display device, an operating method thereof and an integrated control chip are provided and used for detecting a fingerprint of a finger. The display device has a display region. The display device includes a light source, a liquid crystal panel and a plurality of photo sensors. The liquid crystal panel is disposed on the source, the liquid crystal panel includes a first electrode layer, a liquid crystal layer and a second electrode layer, and the liquid crystal layer is disposed between the first electrode layer and the second electrode layer, in which the first electrode layer includes at least one first electrode disposed in the display region, and the first electrode has a plurality of openings. Each photo sensor respectively corresponds to one of the openings.

Description

Display device, its operation method and integrated control chip

The present invention relates to a display device, an operation method thereof, and an integrated control chip, in particular to a display device with a fingerprint recognition function, an operation method thereof, and an integrated control chip.

With the rapid development of technology, portable display devices, such as smart phones, tablet PCs, or laptop PCs, have become essential tools in people's lives. As its functions become more and more diversified, it usually stores private information, such as phonebooks, photos, or personal identification information, with a certain degree of privacy. In order to protect these data, fingerprint recognition devices have been developed to be used in portable display devices. However, the traditional fingerprint recognition device is not light-transmissive, which limits the screen ratio of the display device. For this reason, the industry has developed under-screen fingerprint sensors, such as optical fingerprint sensors, which can detect fingerprint images without affecting the screen-to-body ratio. The current mainstream technology and optical fingerprint sensor display device is an organic light emitting diode display device. The organic light emitting diode display device itself is used as a light source to generate detection light to illuminate the finger, so that the optical fingerprint sensor can detect The fingerprint image is obtained from the light reflected by the finger. However, the light reflected by the finger will diverge into multiple reflected light, which causes the optical fingerprint sensor to receive the reflected light corresponding to the fingerprint at different positions of the finger, which makes the image detected by the fingerprint recognition device poor and affects the result of fingerprint recognition. . Therefore, a collimator is usually provided on the fingerprint sensor to filter out the reflected light with a large incident angle. However, if the collimator is applied to the liquid crystal display device, the brightness of the display device is greatly reduced, and the image cannot be displayed normally. Therefore, the combination of the collimator on the fingerprint sensor can only be applied to expensive organic light-emitting diodes. In the volume display device, the cost of the overall display device cannot be further reduced.

An embodiment of the present invention provides a display device for detecting a fingerprint of a finger. The display device has a display area. The display device includes a light source, a liquid crystal panel and a plurality of light sensors. The liquid crystal panel is disposed on the light source. The liquid crystal panel includes a first electrode layer, a liquid crystal layer, and a second electrode layer. The liquid crystal layer is disposed between the first electrode layer and the second electrode layer. The first electrode layer includes at least A first electrode is arranged in the display area, and the first electrode has a plurality of openings. The light sensors respectively correspond to one of the openings.

Another embodiment of the present invention provides a display device for detecting a fingerprint of a finger. The display device has a display area. The display device includes a liquid crystal display panel, a light source, a local adjustment structure and a plurality of light sensors. The light source is arranged under the liquid crystal display panel. The local adjustment structure is arranged between the light source and the liquid crystal display panel. The local adjustment structure includes a first electrode layer, a liquid crystal layer, and a second electrode layer. When the display device performs fingerprint recognition, the display area where the finger approaches or touches is A fingerprint recognition area, and the haze of the part of the local adjustment structure located in the fingerprint recognition area is smaller than the haze of the other part of the local adjustment structure located outside the fingerprint recognition area. The light sensor is arranged in the display area of the liquid crystal display panel.

Another embodiment of the present invention provides an operating method of a display device. The display device includes a light source, a liquid crystal panel arranged on the light source, and a plurality of light sensors. The liquid crystal panel has a display area, and the light sensor is arranged in the display area. First, enter a fingerprint recognition mode. When a finger approaches or touches the display area of the display device, the display area that is approached or touched by the finger is judged as a fingerprint recognition area, and a fingerprint recognition step is performed. The fingerprint recognition step includes adjusting the liquid crystal panel in the fingerprint recognition area. The liquid crystal molecules make at least a part of the liquid crystal panel located in the fingerprint recognition area present a light-transmitting state, and allow the light generated by the light source to pass through at least a part of the liquid crystal panel and be directed toward the finger, wherein the finger reflects the light as a reflected light; and The sensor detects the reflected light reflected from the finger to obtain a fingerprint image of the finger. Then, it is determined whether the fingerprint image matches a fingerprint information.

Another embodiment of the present invention provides an integrated control chip integrated in a display device. The display device includes a light source, a liquid crystal panel arranged on the light source, and a plurality of light sensors. The integrated control chip is used to control the light source, the liquid crystal panel and the light sensor. The liquid crystal panel has a display area and the light sensor Set in the display area. The integrated control chip includes a touch display control element and a fingerprint recognition control element. The touch display control element is used in the fingerprint recognition mode, when the finger approaches or touches the display area, the display area that the finger approaches or touches is judged as the fingerprint recognition area. The fingerprint recognition control element is used to perform a fingerprint recognition step in the fingerprint recognition mode, wherein the fingerprint recognition step includes adjusting the liquid crystal molecules of the liquid crystal panel located in the fingerprint recognition area so that at least a part of the liquid crystal panel located in the fingerprint recognition area presents a light-transmitting state. The light generated by the light source is allowed to pass through at least a part of the liquid crystal panel and directed toward the finger, where the finger reflects the light as a reflected light; and the light sensor detects the reflected light from the finger to obtain a fingerprint image of the finger.

Those skilled in the art can understand the present invention by referring to the following detailed description in conjunction with the accompanying drawings. It should be noted that in order to make the readers easy to understand and concise the drawings, the drawings of the present invention are only drawn A part of the display device, and the specific elements in the drawings are not drawn according to actual scale. In addition, the number and size of each element in the figure are only for illustration, and not intended to limit the scope of the present invention.

The ordinal numbers used in the specification and the claim, such as "first", "second", etc., are used to modify the elements of the claim. They themselves do not imply and represent that the requested element has any previous ordinal number, nor does it represent The order of a certain request element and another request element, or the order in the manufacturing method, the use of these ordinal numbers is only used to make a request element with a certain name be clearly distinguishable from another request element with the same name .

It should be noted that the technical solutions provided by the different embodiments below can be used interchangeably, combined or mixed to form another embodiment without violating the spirit of the present disclosure.

The display device provided by the present invention generates more collimated detection light through a part of it to detect the image of the fingerprint, so that the reflected light from the finger can also be more collimated. Therefore, the display device is located in the display area. The sensor can detect a clear image of the fingerprint, so that the fingerprint can be detected without affecting the screen-to-body ratio.

Please refer to Figures 1 to 3. Figure 1 is a schematic top view of the display device according to the first embodiment of the present invention, and Figure 2 is a schematic top view of the first electrode display device corresponding to the first embodiment of the present invention. , Figure 3 is a schematic cross-sectional view taken along the section line AA' of Figure 2. For clarity of illustration, Figure 2 only illustrates the top view relationship between the first electrode and the color filter layer. As shown in FIG. 1, the display device 11 provided by this embodiment has a display area DR for displaying images, and the display area DR has a fingerprint recognition area FR for detecting the fingerprint of the finger F. For example, the fingerprint recognition area FR may be an area that the finger F can completely cover, that is, an area where the finger F will be fingerprinted within a certain period of time. In this embodiment, the finger F can be singular or plural. In this embodiment, the fingerprint recognition area FR is not located in a specific area in the display area DR, but is any area in the display area DR where the finger F approaches or touches. In other words, the display device 11 of this embodiment is a fingerprint on display (FOD) display device, and the fingerprint of the finger F can be detected in any area of the display area DR, that is, any area of the display area DR. The areas are all potential fingerprint recognition areas. In other embodiments, the fingerprint recognition area FR is limited to a portion of the display area DR, that is, the potential fingerprint recognition area is limited to a portion of the display area DR. The display device 11 of this embodiment may also have a non-display area NDR located on at least one side of the display area DR. For example, it may surround the display area DR, but is not limited to this. The non-display area NDR may be used, for example, to set peripheral elements or Opaque element. In some embodiments, since the fingerprint recognition area FR is located in the display area DR, the display device 11 may not have the non-display area NDR, that is, it has the feature of no border. In this context, “proximity” refers to the distance at which the display device 11 can detect the fingerprint of the finger F when the finger F has not touched the display device 11. For example, the distance at which the display device 11 can detect the fingerprint of the finger F may be less than the width of the finger F, but is not limited thereto.

As shown in FIGS. 1 to 3, the display device 11 includes a light source 102, a liquid crystal panel 104, and a plurality of light sensors 106. The light source 102 can be used to generate light L1, and the liquid crystal panel 104 is arranged on the light source 102 to control whether the light L1 is allowed to pass through, so that the light L2 emitted from the light emitting surface 104S of the liquid crystal panel 104 can be used for displaying or detecting fingerprints . The liquid crystal panel 104 includes a first electrode layer 108, a liquid crystal layer 110, and a second electrode layer 112. The liquid crystal layer 110 is disposed between the first electrode layer 108 and the second electrode layer 112, and includes liquid crystal molecules 110L, and By controlling the deflection direction of the liquid crystal molecules 110L, the amount of light L1 passing through the liquid crystal panel 104 can be adjusted. The first electrode layer 108 includes at least one first electrode 108E1 disposed in the fingerprint recognition area FR, and the first electrode 108E1 has a plurality of openings OP for allowing light L1 to pass through during fingerprint detection. In this embodiment, the first electrode layer 108 may include a plurality of first electrodes 108E1 with openings OP, which are insulated from each other and arranged in the display region DR. Each light sensor 106 can correspond to one of the openings OP. When the display device 11 is performing fingerprint recognition, by providing a voltage difference between the first electrode 108E1 and the second electrode layer 112 or the first electrode 108E1 and the third electrode layer 114, the liquid crystal molecules 110L corresponding to the first electrode 108E1 can rotate To the dark state (that is, the light L1 cannot pass through the liquid crystal panel 104), for example, the rotation is vertical alignment, and the liquid crystal molecules 110L corresponding to the opening OP will not rotate to the dark state (that is, the light L1 can pass through the liquid crystal panel 104), for example, the horizontal alignment is still Therefore, the light L1 generated by the light source 102 can only pass through the liquid crystal panel 104 corresponding to the opening OP, thereby collimating the light L2 emitted from the light emitting surface 104S of the liquid crystal panel 104. Thereby, the reflected light L3 corresponding to different fingerprint positions received by the light sensor 106 can be reduced, so as to improve the quality of the detected image and improve the accuracy of fingerprint recognition.

Specifically, as shown in FIG. 3, the liquid crystal panel 104 of this embodiment can be, for example, a liquid crystal display panel, so the light source 102 can, for example, include a backlight module for generating flat light L1. The backlight module can be, for example, an edge type or a direct type. When the backlight module is a direct type, the backlight module may, for example, include a plurality of light emitting diodes arranged under the liquid crystal panel 104, but the invention is not limited to this. In addition, the liquid crystal panel 104 of this embodiment may further include a third electrode layer 114 and an insulating layer 116, and the second electrode layer 112 is disposed between the liquid crystal layer 110 and the third electrode layer 114, and the insulating layer 116 is disposed on the first electrode layer. The second electrode layer 112 and the third electrode layer 114 are used to electrically insulate the second electrode layer 112 and the third electrode layer 114. The second electrode layer 112 includes a plurality of second electrodes 112E, and each of the second electrodes 112E may have at least one slit SL. The third electrode layer 114 is exposed in the top view direction TD of the display device 11, so that the third electrode layer 114 is exposed through the second electrode 112E. Providing a voltage difference between 112E and the third electrode layer 114 can generate a horizontal electric field in the liquid crystal layer 110, thereby controlling the deflection of the liquid crystal molecules 110L in the liquid crystal layer 110, so that the display device 11 can display images. In other words, the liquid crystal display panel of this embodiment may be of fringe field switching type, for example. For example, the second electrode 112E can be used as a pixel electrode, and the third electrode layer 114 can be used as a common electrode, but the invention is not limited thereto. In some embodiments, the third electrode layer 114 may also include a plurality of electrodes, respectively corresponding to a second electrode 112E. In this case, one of the second electrode 112E and the electrode may be a pixel electrode, and the other may be a pixel electrode. Common electrode. In some embodiments, the second electrode layer 112 may also include a second electrode 112E with a slit SL and an electrode with a slit at the same time, and the slit SL of the second electrode 112E and the slit of the electrode are in the top view direction TD. Staggered from each other, that is, the liquid crystal display panel can be an in-plane switching type. In some embodiments, the liquid crystal display panel may also be of other types, such as a vertical aligned (VA) type or a multi-domain vertical aligned (MVA) type.

In addition to the first electrode layer 108, the liquid crystal layer 110, the second electrode layer 112, the third electrode layer 114, and the insulating layer 116, the liquid crystal panel 104 of this embodiment may further include a first substrate 118, a thin film transistor layer 120, The color filter layer 122, the black matrix layer 124 and the second substrate 126. The first substrate 118 and the second substrate 126 are disposed opposite to each other, and the liquid crystal layer 110 is disposed between the first substrate 118 and the second substrate 126. In this embodiment, the thin film transistor layer 120, the third electrode layer 114, the insulating layer 116, and the second electrode layer 112 can be sequentially formed on the first substrate 118, and each second electrode 112E can be electrically connected to the thin film The corresponding thin film transistor in the transistor layer 120 (not shown). In some embodiments, when the third electrode layer 114 includes an electrode, the electrode may be electrically connected to a corresponding line (for example, a common line), but it is not limited thereto. Since the elements included in the thin film transistor layer 120, such as thin film transistors, storage capacitors, data lines or scan lines, and their electrical connection methods are well known to those skilled in the art, and there can be many variations, so here Not much to repeat.

In addition, in this embodiment, the color filter layer 122 may be disposed between the second substrate 126 and the liquid crystal layer 110, and the black matrix layer 124 may also be disposed between the second substrate 126 and the liquid crystal layer 110, and the first electrode The layer 108 may be located between the color filter layer 122 and the liquid crystal layer 110 and between the black matrix layer 124 and the liquid crystal layer 110. For example, the color filter layer 122, the black matrix layer 124, and the first electrode layer 108 may be sequentially formed on the second substrate 126, but it is not limited thereto. In some embodiments, the black matrix layer 124 may also be disposed between the color filter layer 122 and the second substrate 126, or the color filter layer 122 may be formed in the opening 124a of the black matrix layer 124. Furthermore, the color filter layer 122 of this embodiment may include a plurality of first color filters 122a, a plurality of second color filters 122b, and a plurality of third color filters 122c, which are disposed on the first electrode. On layer 108. The first color filter 122a, the second color filter 122b, and the third color filter 122c can have different colors, respectively, so that the first color filter 122a, the second color filter 122b, and the third color filter 122a can pass through different colors. The light of the color filter 122c can be mixed with white light. For example, one first color filter 122a, one second color filter 122b, and one third color filter 122c arranged side by side can correspond to the same pixel of the liquid crystal display panel. In addition, the first color filter 122a may be, for example, a red filter, the second color filter 122b may be, for example, a green filter, and the third color filter 122c may be, for example, a blue filter. Limited to this.

Please continue to refer to FIG. 2. In this embodiment, each opening OP of the first electrode 108E1 in the top view direction TD can correspond to the first color filter 122a, the second color filter 122b, or the third color filter, respectively. One of the sheets 122c allows the light L2 used to detect fingerprints to have the same color. The size of the opening OP may be smaller than the size of the corresponding color filter, but is not limited thereto. For example, since the red light is easily absorbed by the human body and the blue light easily affects the photo sensor 106, the opening OP of the first electrode 108E1 may correspond to the green filter, but it is not limited thereto. In some embodiments, the openings OP of the first electrode 108E1 may also correspond to or overlap the first color filter 122a, the second color filter 122b, and the third color filter of the same pixel in the top view direction TD. At least two of the pieces 122c. In addition, the first electrode 108E1 of this embodiment can overlap with a plurality of first color filters 122a, a plurality of second color filters 122b, and a plurality of third color filters 122c in the top view direction TD, but not Limited to this. In addition, the black matrix layer 124 may have a plurality of openings 124a, respectively corresponding to a sub-pixel. For example, the first color filter 122a, the second color filter 122b, and the third color filter 122c may respectively correspond to an opening 124a, as shown in FIG. 3. In other words, the first color filter 122a , The second color filter 122b and the third color filter 122c can respectively cover the corresponding opening 124a.

As shown in FIG. 3, each light sensor 106 can correspond to an opening OP of the first electrode 108E1. For example, in the top view direction TD of the display device 11, each light sensor 106 is disposed or disposed adjacent to the corresponding opening OP. In the corresponding opening OP. In this embodiment, each light sensor 106 can be respectively disposed in an opening 124a of the black matrix layer 124. For example, the light sensor 106 may be disposed in the opening 124a corresponding to the second color filter 122b, and located between the second color filter 122b and the first electrode 108E1, but it is not limited thereto. The position of the light sensor 106 can be determined according to the color of the light to be received. In some embodiments, the light sensor 106 can also be disposed on any layer (horizontal plane) between the black matrix layer 124 and the second substrate 126, for example, on the same layer as the black matrix layer 124, or disposed on the thin film transistor layer 120 in. The light sensor 106 can be, for example, a photodiode or a phototransistor, but is not limited thereto.

In this embodiment, the liquid crystal panel 104 may further include an adhesive layer 128, an upper polarizer 130 and a lower polarizer (not shown), wherein the upper polarizer 130 can be attached to the upper surface of the second substrate 126 through the adhesive layer 128 The upper and lower polarizers can be attached to the lower surface of the first substrate 118 through another adhesive layer (not shown). In order to clearly show the display device 11, the lower polarizer and the adhesive layer are omitted in FIG. 3, but the present invention is not limited to this. Through the polarization directions of the upper polarizer 130 and the lower polarizer and the arrangement direction of the liquid crystal molecules 110L, the liquid crystal panel 104 can reach a bright state and a dark state. The polarization directions of the upper polarizer 130 and the lower polarizer can be adjusted according to actual requirements. In addition, the display device 11 may further include an adhesive layer 132 and a cover plate 134, wherein the cover plate 134 is attached to the polarizer 130 through the adhesive layer 132. In some embodiments, the liquid crystal panel 104 may further include spacers SP disposed in the liquid crystal layer 110 to maintain the thickness of the liquid crystal layer 110.

Please continue to refer to Figure 1 and Figure 2. The first electrodes 108E1 of this embodiment can be distributed in the entire display area DR, so a part of the first electrodes 108E1 are arranged in the display area DR outside the potential fingerprint recognition area which can be used as the fingerprint recognition area FR. For example, the first electrode 108E1 can form a touch element, so that the first electrode 108E1 can detect the position when a finger approaches or touches the display device 11. In this embodiment, the first electrodes 108E1 can be arranged in a matrix and are electrically connected to the touch control element through mutually insulated wires. In other words, the first electrodes 108E1 of this embodiment can form a self-capacitive touch element, but Not limited to this. Since each first electrode 108E1 of this embodiment is used as a touch electrode, it can overlap with a plurality of second electrodes 112E as pixel electrodes in the top view direction TD, but it is not limited to this. The amount of overlap between the second electrode 112E and the single first electrode 108E1 can be adjusted according to the display resolution and touch resolution required by the display device 11.

The driving method of the display device of this embodiment will be further described below. Please refer to FIG. 4 and FIG. 5, and also refer to FIG. 1 and FIG. 3. FIG. 4 shows the synchronization signal of the liquid crystal panel, the driving signal of the third electrode, and the first electrode according to the first embodiment of the present invention. The timing diagram of the driving signal of, FIG. 5 is a schematic diagram of the display device of the first embodiment of the present invention displaying images. As shown in FIGS. 4 and 5, the signal provided by the display device 11 to the liquid crystal panel 104 is the synchronization signal S1, which is provided in the area determined to be the fingerprint recognition area FR (for example, at least a part of the area covered by the finger F) The signal of the first electrode 108E1 is the driving signal S2, and the signal provided to the first electrode 108E1 outside the area determined to be the fingerprint recognition area FR is the driving signal S3. In this embodiment, the synchronization signal S1 can be, for example, a synchronization signal in the vertical direction of the display screen, that is, a vertical synchronization signal (Display V-Sync), which is provided to the liquid crystal panel 104 to indicate a frame time (Frame) and provide synchronization. To the scan line and data line. In each screen period T1, T2, the display device 11 displays a corresponding screen, where the screen periods T1, T2 may respectively have a display driving period DT1, DT2 and an interval period BT1, BT2. The interval periods BT1, BT2 may be, for example, A vertical blank period. In the display driving period DT1, the synchronization signal S1 provided to the liquid crystal panel 104 may be at a high level, and the driving signal S2 provided to the first electrode 108E1 in the fingerprint recognition area FR and the first electrode 108E1 outside the fingerprint recognition area FR The driving signals S3 are all low level, so the liquid crystal molecules 110L can exhibit a horizontal alignment, so that the light L2 emitted from the light emitting surface 104S of the liquid crystal panel 104 can present an image. In the interval BT1, the synchronization signal S1 provided by the display device 11 is at a low level, and the display signal Sx is at a high level, so that the liquid crystal panel 104 continues to display the same screen during the interval BT1. At the same time, in the interval BT1, the driving signal S2 provided to the first electrode 108E1 in the fingerprint recognition area FR and the driving signal S3 provided to the first electrode 108E1 outside the fingerprint recognition area FR can both be at a high level, so that the first electrode 108E1 An electrode 108E1 can detect whether a finger touches the display device 11. The display signal Sx may be, for example, a data enable (DE) signal.

Next, as shown in FIGS. 3 and 4, in the display driving period DT2 of the screen period T2 in which the next screen is displayed, when the display device 11 is about to perform fingerprint recognition, the driving signal S2 is provided to the first electrode 108E1 It can be maintained at the high level until the image of the fingerprint is detected, and then it drops to the low level, that is, the fingerprint detection is stopped. When the finger F touches the fingerprint recognition area FR of the display device 11 (for example, at least a part of the area covered by the finger F), the user cannot view the image of the fingerprint recognition area FR, so the driving signal S2 is maintained at Micro Motion during the display driving period DT2. Bits will not affect the images viewed by the user. When the driving signal S2 is maintained at a high level, a voltage difference will be generated between the first electrode 108E1 and the second electrode 112E located thereunder and/or the first electrode 108E1 and the third electrode layer 114, causing the liquid crystal molecules 110L to deflect to Dark state. For example, the long axis of the liquid crystal molecule 110L can be rotated to a vertical alignment, for example, parallel to the top view direction TD. Since the first electrode 108E1 has an opening OP, the liquid crystal molecules 110L corresponding to the opening OP will not be deflected to a dark state, such as still in a horizontal alignment, so the light L1 from the light source 102 can penetrate the display device 11 corresponding to the opening OP as The detection light (for example, the light L2), and the traveling direction of the detection light can be close to the normal direction of the display surface 1a of the display device 11 (for example, the top view direction TD), thereby improving the collimation of the detection light. In this way, it is possible to reduce the mutual interference of the detection light passing through the adjacent opening OP and the reflected light L3 reflected by the finger, so as to improve the image clarity detected by the light sensor 106.

Furthermore, as shown in FIGS. 1 and 4, the driving signal S3 provided to the first electrode 108E1 located outside the fingerprint recognition area FR is at a low level during the display driving period DT2, so the display outside the fingerprint recognition area FR Area DR can still display the screen normally. In other words, the display area DR other than the area covered with the finger F and where fingerprint recognition will be performed on the finger F within a certain period of time can still display the screen normally. In addition, when the display device 11 does not perform fingerprint recognition, the driving signal S2 provided to the first electrode 108E1 is at a low level in other driving periods (for example, the display driving period DT3), so that the fingerprint recognition area FR of the display device 11 can be The image is displayed, as shown in FIG. 5, so the entire display area DR of the display device 11 can display a complete image.

It can be seen from the above that the display device 11 of this embodiment not only uses the liquid crystal panel 104 as a device for displaying images, but can also collimate the detection light penetrating the liquid crystal panel 104 so that the light sensor 106 of the display device 11 can detect A clear fingerprint image is detected, so the display device 11 can have a fingerprint recognition function. In this way, the overall cost of the display device 11 can be effectively reduced.

The display device of the present invention is not limited to the above-mentioned embodiment. In order to facilitate the comparison of the differences between the first embodiment and other embodiments and simplify the description, the same symbols are used to denote the same elements in the other embodiments below, and the differences between the first embodiment and other embodiments are mainly discussed. The differences are explained instead of repeating parts.

Please refer to FIG. 6, which is a schematic top view of a display device according to a variation of the first embodiment of the present invention. As shown in FIG. 6, the difference between this modified embodiment and the above-mentioned embodiment is that a part of the first electrode 108E1 of the display device 12 can be replaced with a third electrode 108E2 that does not have an opening, and the third electrode 108E2 is disposed in the display area DR . Since the third electrode 108E2 does not have an opening, the portion of the display device 12 corresponding to the third electrode 108E2 cannot perform fingerprint recognition. In other words, the display area DR corresponding to the third electrode 108E2 does not have a fingerprint recognition function. In this modified embodiment, the distribution range of the third electrode 108E2 may be determined according to the arrangement area of the first electrode 108E1. For example, the distribution range of the first electrode 108E1 is a potential fingerprint recognition area that can be used as the fingerprint recognition area FR, and the third electrode 108E2 is disposed outside the potential fingerprint recognition area, but it is not limited to this. The third electrode 108E2 may be formed by the first electrode layer 108, for example. In the top view direction TD, the first color filter 122a, the second color filter 122b, and the third color filter 122c may, for example, completely overlap the third electrode 108E2. The outline size of the third electrode 108E2 may be the same as the outline size of the first electrode 108E1, but is not limited thereto. In the driving method of the display device 12 of this modified embodiment, the third electrode 108E2 provides the driving signal S3. Since the first electrode 108E1 and the driving signal provided in this modified embodiment are the same as those in the above-mentioned embodiment, it will not be repeated here.

Please refer to FIG. 7, which illustrates a schematic diagram of a method for fingerprint recognition by a display device according to a second embodiment of the present invention. As shown in FIG. 7, the display device 2 provided in this embodiment may include a liquid crystal display panel 204 and a light source 102. The liquid crystal display panel 204 of this embodiment can be any type of liquid crystal display panel, such as a vertical alignment type or a lateral electric field switching type liquid crystal display panel, but it is not limited thereto. For example, the liquid crystal display panel 204 may include a color filter substrate 2041, a thin film transistor substrate 2042, a liquid crystal layer 110, an upper polarizer 230 and a lower polarizer 216. The liquid crystal layer 110 is disposed on the color filter substrate 2041 and the thin film. Between the transistor substrates 2042, the upper polarizer 230 and the lower polarizer 216 are respectively disposed on the light-emitting surface 204S1 and the light-incident surface 204S2 of the liquid crystal display panel 204. In addition, the liquid crystal display panel 204 may include a plurality of pixels PX1, PX2, and each pixel PX1, PX2 may, for example, include sub-pixels SPX1, SPX2, SPX3, respectively. In the present invention, the number of sub-pixels SPX1, SPX2, and SPX3 in each pixel PX1, PX2 is not limited to this. In this embodiment, when the display device 2 performs fingerprint recognition, a part of the non-adjacent pixels PX1 located in the fingerprint recognition area FR can be turned on, and the other part of the non-adjacent pixels PX2 are turned off, so that the fingerprint recognition area FR The liquid crystal layer 110 of the pixels PX1 and PX2 may form a grating 110G. In other words, the turned-on pixels PX1 and the turned-off pixels PX2 are alternately arranged in sequence. In this way, the size of the opening 110a of the grating 110G and the distance between the openings 110a can be reduced to reduce the divergence angle θ of the light penetrating the liquid crystal display panel 204, thereby reducing the incident angle of the reflected light entering the light sensor, thereby effectively increasing Detect the collimation of light. The width of the turned-on pixel PX1 and the width of the turned-off pixel PX2 may be, for example, 60 μm, but is not limited thereto. For example, the number of pixels PX1 between adjacent and turned-off pixels PX2 may be one, and the number of pixels PX2 between adjacent and turned-on pixels PX1 may be one. Therefore, for a single point light source, The divergence angle θ of the light generated by the light source may be less than 11 degrees, but is not limited to this. The light divergence angle θ, the width of the open pixel PX1 and the width of the closed pixel PX2 can be adjusted by changing the number of pixels PX1 between adjacent and closed pixels PX2 and the number of pixels PX2 between adjacent and open pixels PX1 . In some embodiments, the display device 2 may optionally further include a touch element and a cover plate, which are disposed on the liquid crystal display panel 204.

Please refer to FIG. 8, which illustrates a schematic diagram of a method for fingerprint recognition on a display device according to a modified embodiment of the second embodiment of the present invention. As shown in Fig. 8, the difference between this modified embodiment and the above-mentioned embodiment is that the display device 2 provided by this modified embodiment only turns on the non-adjacent sub-pixel SPX2 in the fingerprint recognition area FR when performing fingerprint recognition. , And turn off other sub-pixels SPX1 and SPX3 to form a grating 110G. Since only the width W of a single sub-pixel SPX2 allows light to pass through in this modified embodiment, the width of the opening 110a of the grating 110G can be reduced to reduce the divergence angle of the light penetrating the liquid crystal display panel 204, for example, a single point light source In other words, the divergence angle θ of the light generated by the point light source can be reduced to less than 4 degrees. This can effectively improve the collimation of the detection light. In this modified embodiment, the sub-pixels SPX2 that are turned on may, for example, all be sub-pixels that produce the same color, such as a green sub-pixel. In addition, there may be at least two turned-off sub-pixels between adjacent and turned-on green sub-pixels SPX2, such as sub-pixels SPX1 and SPX3. In this modified embodiment, when fingerprint recognition is performed, the turned-on green sub-pixel SPX2 is not the adjacent green sub-pixel SPX2, but a turned-off green sub-pixel SPX2 is provided in between, and other such as red sub-pixel SPX1 or The blue sub-pixel SPX3 can be turned off, but not limited to this. In some embodiments, as the distance between two adjacent sub-pixels SPX2 that are turned on increases (or the number of sub-pixels increases), the mutual interference of the detection light emitted from two adjacent sub-pixels SPX2 can be reduced. To improve the quality of the detected image. For example, there may be at least four sub-pixels between two adjacent sub-pixels SPX2 that are turned on.

Please refer to FIG. 9, which is a schematic cross-sectional view of a display device according to a third embodiment of the present invention. As shown in FIG. 9, the difference between the display device 31 provided by this embodiment and the display device 11 shown in FIG. 3 is that the liquid crystal panel 304 of the display device 31 is used for collimating and detecting light. A liquid crystal display panel 340 is included between the light source 102 and the liquid crystal panel 304 for displaying images. Specifically, the liquid crystal panel 304 of this embodiment may only include the second substrate 126, the first electrode layer 308, the liquid crystal layer 110, the second electrode layer 312, and the first substrate 118, but does not include the thin film transistor layer, the third Electrode layer, color filter layer and black matrix layer. The first electrode layer 308 may include at least one first electrode 308E1, and the first electrode 308E1 of this embodiment may have a similar or same pattern as the first electrode of the first embodiment, and therefore may have a plurality of openings OP. The first electrode 308E1 can overlap the second electrode layer 312 in the top view direction TD, and the bright state and the dark state of the liquid crystal panel 304 can be adjusted through the voltage difference between the first electrode 308E1 and the second electrode layer 312. Since the first electrode 308E1 has an opening OP, when the display device 31 performs fingerprint recognition, the portion of the liquid crystal panel 304 corresponding to the first electrode 308E1 can be in a dark state, and the portion corresponding to the opening OP can be in a bright state, so that the detection light (For example, light L2) can be collimated. In this embodiment, the liquid crystal panel 304 may further include an upper polarizer 330U and a lower polarizer 330L, which are attached to the upper surface of the second substrate 126 and the lower surface of the first substrate 118 through the adhesive layers AL1 and AL2, respectively. In addition, the liquid crystal panel 304 can be pasted on the light emitting surface 340S of the liquid crystal display panel 340 through the adhesive layer AL3. In some embodiments, the first electrode 308E1 can be distributed in the entire display area, so that the first electrode 308E1 can form a touch element for detecting the position of the finger, but it is not limited thereto. In some embodiments, the first electrode layer 308 may optionally further include a plurality of third electrodes (not shown), and the first electrode 308E1 and the third electrode may form a touch element for detecting the position of a finger. In some embodiments, the display device 31 may further include a touch panel, which is disposed on the liquid crystal panel 304.

The liquid crystal display panel 340 of this embodiment can be any type of liquid crystal display panel. The following uses a fringe electric field switching type as an example, but it is not limited thereto. The difference between the liquid crystal display panel 340 of this embodiment and the liquid crystal panel 104 shown in FIG. 3 is that the liquid crystal display panel 340 does not include a first electrode layer, and therefore does not have a touch sensing function and a fingerprint recognition function. For example, the liquid crystal display panel 340 may include a third substrate 342, a fourth substrate 344, another liquid crystal layer 346, a thin film transistor layer 348, a third electrode layer 350, an insulating layer 352, a fourth electrode layer 354, and a color filter. The light layer 122 and the black matrix layer 124. In this embodiment, the third substrate 342, the fourth substrate 344, the other liquid crystal layer 346, the thin film transistor layer 348, the third electrode layer 350, the insulating layer 352, the fourth electrode layer 354, the color filter layer 122 and the black matrix The layer 124 may be similar or the same as the first substrate, the second substrate, the liquid crystal layer, the thin film transistor layer, the third electrode layer, the insulating layer, the second electrode layer, the color filter layer, and the black matrix layer of the first embodiment, respectively. , So I won’t go into details here. Although not shown in FIG. 9, the liquid crystal display panel 340 may further include a lower polarizer disposed between the third substrate 342 and the light source 102. The liquid crystal display panel 340 of this embodiment can share the lower polarizer 330L with the liquid crystal panel 304 without the need to additionally provide another upper polarizer, but it is not limited to this.

In addition, in this embodiment, each opening OP of the first electrode 308E1 may correspond to one of the first color filter 122a, the second color filter 122b, or the third color filter 122c in the top view direction TD. For example, each opening OP can expose a corresponding second color filter 122b in the top view direction TD, so that the light L2 emitted from the liquid crystal display panel 340 can pass through the portion of the liquid crystal panel 304 corresponding to the opening OP as the detection light . The light sensor 306 of this embodiment may be disposed in the liquid crystal display panel 340, for example, disposed in the opening 124a of the black matrix layer 124 corresponding to the opening OP of the first electrode 308E1, but is not limited thereto. In some embodiments, the light sensor 306 may also be disposed in the thin film transistor layer 348 corresponding to the opening OP of the first electrode 308E. In some embodiments, the light sensor 306 can also be disposed in the liquid crystal panel 304.

Please refer to FIG. 10, which is a schematic cross-sectional view of a display device according to a modified embodiment of the third embodiment of the present invention. As shown in FIG. 10, the difference between the display device 32 provided by this embodiment and the display device 31 shown in FIG. 9 is that the display device 32 uses a self-luminous display panel 356 instead of the liquid crystal display panel and the backlight module. Specifically, the light source 102 includes a self-luminous display panel 356, such as an organic light-emitting diode display panel, disposed under the liquid crystal panel 304, that is, the liquid crystal panel 304 is disposed between the self-luminous display panel 356 and the cover plate 134. In this embodiment, the self-luminous display panel 356 may include a plurality of first light-emitting elements 358a, a plurality of second light-emitting elements 358b, and a plurality of third light-emitting elements 358c, which are disposed on the third substrate 342 for displaying images. The first light-emitting element 358a, the second light-emitting element 358b, and the third light-emitting element 358c can respectively generate light of different colors to mix white light. For example, the first light-emitting element 358a can generate blue light, and the second light-emitting element 358b can generate light. For green light, the third light-emitting element 358c can generate red light, but is not limited thereto. The first light-emitting element 358a, the second light-emitting element 358b, and the third light-emitting element 358c may include organic light-emitting diodes or inorganic light-emitting diodes. In this embodiment, the openings OP of the first electrode 308E1 respectively correspond to or overlap with one of the first light-emitting element 358a, the second light-emitting element 358b, or the third light-emitting element 358c in the top view direction TD, for example, may correspond to or overlap It is one of the second light-emitting elements 358b for generating green light.

In addition, the self-luminous display panel 356 may include a plurality of thin-film transistors TFT, which are respectively electrically connected to the first light-emitting element 358a, the second light-emitting element 358b, and the third light-emitting element 358c, and the light sensor 306 may be disposed in the self-luminous Display panel 356. The light sensor 306 and the light emitting element can be formed on the same third substrate 342. For clarity of illustration, the thin-film transistor TFT, the light-emitting element, and the light sensor 306 in Figure 10 are respectively represented by a single block, and the thin-film transistor layer is omitted. However, the present invention is not limited to this. The thin-film transistor, the light-emitting element and the light sensor 306 The sensor can also be formed in the same thin film transistor layer. In some embodiments, the light sensor 306 may also be disposed on the lower surface of the third substrate 342. In addition, the self-luminous display panel 356 may further include a packaging cover 360 covering the thin film transistor TFT, the light sensor 306 and the light-emitting element. In some embodiments, the encapsulation cover 360 may be replaced by an encapsulation layer.

Please refer to FIG. 11, which is a schematic cross-sectional view of a display device according to a fourth embodiment of the present invention. As shown in FIG. 11, the difference between the display device 4 provided in this embodiment and the third embodiment is that the liquid crystal panel 404 can be disposed between the liquid crystal display panel 440 and the light source 402. Since the liquid crystal panel 404 of this embodiment may be the same as the liquid crystal panel 304 of the third embodiment, it will not be repeated here. In this embodiment, the liquid crystal display panel 440 may have a display area DR, and the light sensor 406 may be disposed in the display area DR of the liquid crystal display panel 440, and is disposed corresponding to the opening OP of the first electrode 308E1, for example, in the top view direction TD Above, each light sensor 406 may be adjacent to the corresponding opening OP, so that each light sensor 406 only detects the detection light passing through the corresponding opening OP, but it is not limited to this. For clarity of illustration, the liquid crystal display panel 440 in FIG. 11 only illustrates the third substrate 342, the fourth substrate 344, the liquid crystal layer 346, and the photo sensor 406, and omits other elements or layers, but the present invention is not limited thereto. In some embodiments, each opening OP of the first electrode 308E1 can still correspond to one of the first color filter, the second color filter, or the third color filter in the top view direction TD. In some embodiments, the display device 4 may further include a touch panel, which is disposed on the liquid crystal display panel 440.

In this embodiment, the light source 402 may be, for example, an edge-type backlight module, which may include a light-emitting element 462, a light guide plate 464, a reflection sheet 466, a brightness enhancement film 468 and 470, and a diffusion sheet 472. The light emitting element 462 can be arranged on the side of the light guide plate 464, the reflective sheet 466 is arranged under the light guide plate 464, the brightness enhancement films 468 and 470 are sequentially stacked on the light emitting surface 464S of the light guide plate 464, and the diffusion sheet 472 is arranged on the light guide plate 464. Bright film 470 on. The brightness enhancement films 468 and 470 of the present embodiment may, for example, respectively have a plurality of strips extending along different directions, but it is not limited thereto. In some embodiments, the light source 402 may also be a direct type backlight module. In some embodiments, the light source 402 may include a plurality of light emitting diodes, which are dispersedly arranged directly under the liquid crystal display panel 440.

Please refer to FIGS. 12 and 13. FIG. 12 is a schematic top view of a display device according to a fifth embodiment of the present invention, and FIG. 13 is a schematic cross-sectional view of FIG. 12 along the line B-B'. As shown in FIGS. 12 and 13, the difference between the display device 51 provided in this embodiment and the fourth embodiment is that the light source 502 can omit the diffuser, and the liquid crystal panel can be replaced by a partial adjustment structure 574. Specifically, since the light source 502 omits the diffuser, when the display device 51 displays images, the local adjustment structure 574 disposed between the light source 502 and the liquid crystal display panel 440 needs to have a certain haze to reduce the light source 502 The generated light L1 is uniformly diffused, so that the local adjustment structure 574 needs to have a function of diffusing light when displaying images. In addition, when the display device 51 performs fingerprint recognition, the haze of the part P1 of the local adjustment structure 574 located in the fingerprint recognition area FR can be smaller than the haze of the part P2 of the local adjustment structure 574 located outside the fingerprint recognition area FR, that is, the local The penetration rate of the portion P1 of the adjustment structure 574 located in the fingerprint recognition area FR is greater than the penetration rate of the portion P2 of the local adjustment structure 574 located outside the fingerprint recognition area FR. For example, the part P1 of the local adjustment structure 574 located in the fingerprint recognition area FR may be transparent. Therefore, the light L1 generated by the light source 502 can penetrate the transparent portion P1 of the local adjustment structure 574 without being diverged by the diffuser, so that the detection light emitted from the fingerprint recognition area FR of the liquid crystal display panel 440 can be close to collimation In this way, the fingerprint image detected by the light sensor 406 can be improved.

In this embodiment, the local adjustment structure 574 may include a first substrate 518, a second substrate 526, a first electrode layer 576, a liquid crystal layer 578, and a second electrode layer 580, wherein the first substrate 518 is disposed on Between the second substrate 526 and the light source 502, the liquid crystal layer 578 is disposed between the first substrate 518 and the second substrate 526, the first electrode layer 576 is disposed between the liquid crystal layer 578 and the first substrate 518, and the second electrode layer 580 is disposed between the liquid crystal layer 578 and the second substrate 526. The first electrode layer 576 may include a plurality of adjustment electrodes 576E, which are insulated from each other and arranged in the display area DR. For example, the adjustment electrodes 576E are arranged in an array, and the second electrode layer 580 can cover the entire display area DR, but it is not limited thereto. At least one of the adjustment electrodes 576E may be disposed in the fingerprint recognition area FR. For example, one of the adjustment electrodes 576E may cover the fingerprint recognition area FR, but is not limited thereto. The liquid crystal molecules of the liquid crystal layer 578 of this embodiment may include polymer disperse liquid crystal (PDLC), polymer network liquid crystal (PNLC), cholesteric liquid crystal, or other suitable ones. liquid crystal. In addition, the local adjustment structure 574 may further include a plurality of wires 582 to electrically connect the adjustment electrodes 576E to the control element 584 separately. In some embodiments, the positions of the first electrode layer 576 and the second electrode layer 580 are interchangeable.

The following will further describe the driving method of the display device 51 of this embodiment when performing fingerprint recognition, and the liquid crystal layer 578 is a polymer dispersed liquid crystal as an example, but it is not limited thereto. Please refer to FIG. 14 and also refer to FIG. 12 and FIG. 13. FIG. 14 is a timing diagram of driving signals provided to the adjustment electrodes located in and outside the fingerprint recognition area. As shown in Figures 12 to 14, when the display device 51 performs fingerprint recognition, the display device 51 will provide a drive signal S4 to the adjustment electrode 576E located in the fingerprint recognition area FR, and a drive signal S5 to be located in the fingerprint recognition area Adjustment electrode 576E outside FR. Since the display device 51 provides the driving signal to the second electrode layer 580 during fingerprint recognition and the driving signal S5 provided to the adjustment electrode 576E located outside the fingerprint recognition area FR, the driving signal S5 is the same or has a similar voltage value, so it is not illustrated in No. 14 In the picture. In this embodiment, the driving signal S5 may be a DC signal and a certain voltage V1. The driving signal S4 will be provided in an alternating current manner. The driving signal S4 may be, for example, a square wave signal, that is, the peak value V2 of the driving signal S4 may be greater than the driving signal S4. The voltage V1 of the signal S5, and the valley value V3 can be less than the voltage V1 of the driving signal S5. For example, the voltage V1 may be the average value of the peak value V2 and the valley value V3, so that the difference between the voltage V1 and the peak value V2 may be the same as the difference between the voltage V1 and the valley value V3, so that the liquid crystal layer 578 in the fingerprint recognition area FR The transparency continues to be consistent.

Please refer to FIG. 13 and FIG. 14, when the display device 51 performs fingerprint recognition, a voltage difference is provided between the adjustment electrode 576E located in the fingerprint recognition area FR and the second electrode layer 580, so that it is located in the fingerprint recognition area FR The liquid crystal layer 578 is transparent, so the light L1 generated by the light source 502 can penetrate the transparent part P1 of the local adjustment structure 574 and the liquid crystal display panel 440 without being scattered, thereby collimating the emitted detection light; There is no voltage difference between the adjustment electrode 576E located outside the fingerprint recognition area FR and the second electrode layer 580, so that the liquid crystal layer 578 located outside the fingerprint recognition area FR presents an opaque or semi-transparent fog shape, so the light source 502 generates The light from φ can be scattered by the liquid crystal layer 578, and the light-emitting surface 574S of the local adjustment structure 574 outside the fingerprint recognition area FR emits uniform light for displaying images.

Please refer to FIG. 15, which is a schematic top view of a display device according to a variation of the fifth embodiment of the present invention. The difference between the display device 52 of this modified embodiment and the display device 51 of FIG. 12 is that the first electrode layer 576 of this modified embodiment may include a plurality of first electrode strips 576SE, and the second electrode layer 580 includes a plurality of first electrode strips 576SE. Two electrode bars 580SE, and the first electrode bars 576SE and the second electrode bars 580SE are staggered in the top view direction TD. In this modified embodiment, the first electrode strip 576SE and the second electrode strip 580SE can form a plurality of overlapping regions OR in the top view direction TD, and at least one overlapping region OR can be located in the fingerprint recognition area FR to pass through the first electrode The voltage difference between the strip 576SE and the second electrode strip 580SE controls the overlap area OR in the fingerprint recognition area FR to appear transparent, and the overlap area OR outside the fingerprint recognition area FR appears foggy.

Please refer to FIG. 16, which is a schematic cross-sectional view of a display device according to another modified embodiment of the fifth embodiment of the present invention. The difference between the display device 53 of this modified embodiment and the display device 51 shown in FIG. 12 is that the display device 53 of this modified embodiment may include an image sensor 592 disposed under the backlight module 594, and the image sensor The sensor 592 can replace the light sensor 406 in the display device 51 to detect the fingerprint image of the finger. In this modified embodiment, the display device 53 may further include another light source 596 for generating light for detecting the fingerprint image, but it is not limited thereto. In other embodiments, the display device 53 may not include the light source 596. The light source 596 may be disposed under the backlight module 594, for example. In this modified embodiment, the design of the backlight module 594 can allow the light of the light source 596 to penetrate, and the image sensor 592 can detect the reflected light from the finger. For example, the image sensor 592 may include a complementary metal oxide semiconductor (CMOS) image sensor chip, but is not limited to this. The light source 596 may include, for example, a visible light emitting diode or an invisible light emitting diode. The visible light emitting diode can be, for example, an infrared light emitting diode, but it is not limited to this. In some embodiments, the image sensor 592 may also be disposed in the backlight module 594, for example, disposed between the light guide plate and the reflective sheet, but it is not limited thereto. The partial adjustment structure 574, the liquid crystal display panel 440, and the cover plate 134 of this modified embodiment can be applied to the partial adjustment structure, the liquid crystal display panel, and the cover plate of the above-mentioned embodiment, so it will not be repeated here.

Please refer to FIG. 17, which is a block diagram of the control element of the display device according to the sixth embodiment of the present invention. In this embodiment, the display device 61 can be applied to the display device of any of the above embodiments. The following takes the display device 61 as the display device 51 in FIG. 13 as an example for further details. As shown in FIGS. 13 and 17, the display device 61 may include a backlight control element 686, an integrated control element 688, and a main element 690, which are electrically connected to each other. The integrated control element 688 may include a touch display control element 688T and a fingerprint Identify the control element 688F. The backlight control element 686 can be used to control the brightness of the light source 502 and the partial adjustment structure 574, so that the partial adjustment structure 574 is partially transparent or foggy. The integrated control element 688 can be used to control the light source 502, the local adjustment structure 574, and the light sensor 406. The touch display control element 688T can be used to control the touch element to detect the position where the finger is close or touched. In the fingerprint recognition mode, when the finger closes or touches the display area DR, the finger closes or touches the display area DR. The area is judged to be the fingerprint recognition area FR. The fingerprint recognition control element 688F can be used to control the light source 502, the local adjustment structure 574, and the light sensor 406 to perform a fingerprint recognition step in the fingerprint recognition mode to obtain a fingerprint image of the finger. Therefore, when the touch display control element 688T in the integrated control element 688 detects that the finger is approaching or touching the display device 61, it can send this message directly to the fingerprint recognition control element 688F and directly to the backlight control element 686, or It is transmitted to the backlight control element 686 through the main element 690 for fingerprint recognition. When the fingerprint recognition control element 688F detects a fingerprint image, it can directly or through the main element 690 notify the backlight control element 686 to stop fingerprint recognition. In this embodiment, the integrated control element 688 may be a single chip with a micro processor (MCU). In some embodiments, when the display device 61 can be applied to the display devices of the first to fourth embodiments described above, the integrated control element 688 can be used to control the light source, the liquid crystal panel, and the light sensor.

Please refer to FIG. 18, which shows a block diagram of a control element of a display device according to a variation of the sixth embodiment of the present invention. As shown in Figure 18, the difference between the display device 62 of this modified embodiment and the display device 61 of the above-mentioned embodiment is that the touch display control element 688T and the fingerprint recognition control element 688F of the display device 62 of this modified embodiment are separated from each other. Therefore, the touch display control element 688T and the fingerprint recognition control element 688F can be electrically connected to the main element 690 respectively. In this modified embodiment, the touch display control element 688T can be electrically connected to the fingerprint recognition control element 688F. Therefore, the touch display control element 688T can directly or through the main element 690 send a message to the fingerprint recognition control element 688F to further directly notify or notify the backlight control element 686 through the main element 690 to adjust the partial adjustment structure 574 to show partial transparency or entire surface Misty. Similarly, in this modified embodiment, the touch display control element 688T and the fingerprint recognition control element 688F may be single chips with micro-processors (MCUs), respectively.

Hereinafter, the operation method of the above-mentioned display device will be further described. Please refer to FIG. 19, which is a schematic flowchart of the operation method of the display device according to the seventh embodiment of the present invention. The display device of this embodiment can also be applied to the display device of any of the above-mentioned embodiments. As shown in FIG. 19, the operating method of the display device provided in this embodiment includes step S12 to step S30. For the convenience of description, the following will take the display device 11 in FIG. 3 as an example in conjunction with the process in FIG. 19 in further detail, but it is not limited to this. First, proceed to step S12 to make the display device 11 enter the fingerprint recognition mode. For example, the user can perform step S12 by pressing a function key of the display device 11 or detecting whether a finger touches the display device 11 through the display device 11, but it is not limited to this. Then, step S16 is performed, that is, a touch detection step is performed to detect whether a finger approaches or touches the display device 11. When a finger approaches or touches the display area DR of the display device 11, the area of the display area DR where the finger approaches or touches is determined as the fingerprint recognition area FR. When the display device 11 determines that there is no finger approaching or touching, step S16 is performed again until a finger approaching or touching is detected. In some embodiments, the operation method may further include performing step S14 between step S12 and step S16 to use the display device 11 to display the position of the fingerprint recognition area FR, so that the user can know the fingerprint recognition area position.

When the display device 11 determines that there is a finger approaching or touching, a fingerprint recognition step is performed. The fingerprint recognition step may include step S18 and step S20. In step S18, the alignment direction of the liquid crystal molecules 110L of the liquid crystal panel 104 in the fingerprint recognition area FR is adjusted so that at least a part of the liquid crystal panel 104 in the fingerprint recognition area FR is in a light-transmitting state, and the light L1 generated by the light source 102 is allowed At least a part L2 of the liquid crystal panel 104 is projected toward the finger F, where the finger F reflects the light L2 into a reflected light L3. For example, in step S18, a voltage difference may be provided between the first electrode 108E1 and the second electrode 112E and/or the first electrode 108E1 and the third electrode layer 114, so that the voltage difference with the first electrode 108E1 in the top view direction TD The overlapping liquid crystal molecules 110l can be vertically aligned, so the portion of the liquid crystal panel 104 corresponding to the first electrode 108E1 can be in a light-tight state, while the liquid crystal molecules 110L that do not overlap the first electrode 108E1 in the top view direction TD can be horizontally aligned Therefore, the portion of the liquid crystal panel 104 corresponding to the opening OP of the first electrode 108E1 can present a light-transmitting state. This can help to collimate the light L2 emitted from the light-emitting surface 104S of the liquid crystal panel 104. In some embodiments, the display device 11 may not perform step S16, but directly perform step S18 after step S12 or step S14.

In this embodiment, step S18 may optionally include increasing the brightness of the light corresponding to a part of the liquid crystal panel 104. Specifically, in order to increase the brightness of the reflected light L3 detected by the light sensor 106, the brightness of the light L2 emitted from the portion of the liquid crystal panel 104 located in the fingerprint recognition area FR can be further increased in this step S18. . For example, without affecting the image displayed by the display device 11 in the display area outside the fingerprint recognition area FR, local dimming technology can be used to increase the height of the light source 102 located in the fingerprint recognition area. The brightness of light L1, but not limited to this.

Then, in step S20, the light sensor 106 is used to detect the reflected light L3 reflected from the finger F to obtain a fingerprint image of the finger F. Then, step S22 is performed to compare the detected fingerprint image with a piece of fingerprint information to determine whether the fingerprint image matches the fingerprint information. In this embodiment, the fingerprint information can be pre-stored in the display device 11, but it is not limited to this. In some embodiments, the fingerprint information may include at least one fingerprint image.

When the fingerprint image matches the fingerprint information, step S24 is performed to execute a specific function. For example, specific functions may be to allow users to use mobile phones, to allow financial transactions, or to allow access to private data, but not limited to this. When the fingerprint image does not conform to the fingerprint information, step S26 can be selectively performed to count the number of non-conformities.

Then, step S28 is performed to determine whether the number of non-conformances is greater than N, where N can be a positive integer, for example, 3 or 5. When the number of non-conformances is greater than N, step S30 can be selectively performed to enter another verification mode, so that the user can still perform a specific function. For example, another verification mode may be a password input mode, a pattern unlock mode, or other suitable verification modes. When the number of non-conformances is less than or equal to N, step S16 can be selectively performed again.

In summary, the display device provided by the present invention can not only use the liquid crystal display panel as a device for displaying images, but also collimate the detection light penetrating the liquid crystal display panel through the opening of the first electrode or the partial adjustment structure, so that the display The light sensor of the device can detect a clear fingerprint image, so the display device can have a fingerprint recognition function in the display area. In this way, the overall cost of the display device can be effectively reduced. The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made in accordance with the scope of the patent application of the present invention should fall within the scope of the present invention.

11, 12, 2, 31, 32, 4, 51, 52, 53, 61, 62: display device 1a: display surface 102, 402, 502, 596: light source 104, 304, 404: LCD panel 104S, 204S1, 340S, 574S light emitting surface 106, 306, 406: light sensor 108, 308, 576: the first electrode layer 108E1, 308E1: first electrode 108E2: third electrode 110, 346, 578: liquid crystal layer 110L: liquid crystal molecules 110G: grating 112, 312, 580: second electrode layer 112E: second electrode 114, 350: third electrode layer 116, 352: insulating layer 118, 518: first substrate 120, 348: thin film transistor layer 122: color filter layer 122a: The first color filter 122b: second color filter 122c: third color filter 124: black matrix layer 126, 526: second substrate 128, 132, AL1, AL2, AL3: Adhesive layer 130, 230, 330U: upper polarizer 134: Cover Board 204, 340, 440 LCD panel 204S2: Glossy surface 2041: Color filter substrate 2042: Thin Film Transistor Substrate 216, 330L: lower polarizer 342: third substrate 344: fourth substrate 354: fourth electrode layer 356: Self-luminous display panel 358a: the first light-emitting element 358b: second light-emitting element 358c: third light-emitting element 360: package cover 462: light-emitting element 464: light guide plate 466: reflection sheet 468, 470: Brightness enhancement film 472: diffuser 574: local adjustment structure 576E: Adjust electrode 576SE: The first electrode strip 580SE: second electrode strip 582: Wire 584: control element 592: Image Sensor 594: Backlight module 686: Backlight control element 688: Integrated control components 688T: Touch display control element 688F: Fingerprint recognition control element 690: main component A-A’, B-B’: Sectional line DR: display area FR: Fingerprint recognition area F: Finger NDR: non-display area OR: overlapping area P1, P2: Partial SPX1, SPX2, SPX3: sub-pixel PX1, PX2: pixels θ: divergence angle W: width L1, L2: light L3: reflected light OP, 110a, 124a: opening SL: slit TFT: Thin Film Transistor SP: Spacer S1: Sync signal S2, S3, S4, S5: drive signal Sx: display signal T1, T2: screen time period DT1, DT2, DT3: Display driving period BT1, BT2: interval time TD: Looking down direction V1: Voltage V2: Peak V3: Valley S12, S14, S16, S18, S20, S22, S24, S26, S28, S30: steps

FIG. 1 is a schematic top view of the display device according to the first embodiment of the present invention. FIG. 2 is a schematic top view of a display device corresponding to a single first electrode located in the fingerprint recognition area and a third electrode outside the fingerprint recognition area according to the first embodiment of the present invention. Fig. 3 is a schematic cross-sectional view taken along the section line A-A' of Fig. 2. FIG. 4 is a timing diagram of the synchronization signal of the liquid crystal panel, the driving signal of the third electrode, and the driving signal of the first electrode of the first embodiment of the present invention. FIG. 5 is a schematic diagram of displaying images by the display device according to the first embodiment of the present invention. FIG. 6 is a schematic top view of a display device according to a modified embodiment of the first embodiment of the present invention. FIG. 7 is a schematic diagram of a method for fingerprint recognition by the display device according to the second embodiment of the present invention. FIG. 8 is a schematic diagram of a method for fingerprint recognition on a display device according to a modified embodiment of the second embodiment of the present invention. FIG. 9 is a schematic cross-sectional view of a display device according to a third embodiment of the invention. FIG. 10 is a schematic cross-sectional view of a display device according to a modified embodiment of the third embodiment of the present invention. FIG. 11 is a schematic cross-sectional view of a display device according to a fourth embodiment of the present invention. FIG. 12 is a schematic top view of a display device according to a fifth embodiment of the invention. Figure 13 is a schematic cross-sectional view of Figure 12 along the section line B-B'. FIG. 14 is a timing diagram of driving signals provided to the adjustment electrodes located in and outside the fingerprint recognition area. FIG. 15 is a schematic top view of a display device according to a modified embodiment of the fifth embodiment of the present invention. Figure 16 is a schematic cross-sectional view of a display device according to another modified embodiment of the fifth embodiment of the present invention FIG. 17 is a block diagram of the control element of the display device according to the sixth embodiment of the present invention. FIG. 18 is a block diagram of a control element of a display device according to a modified embodiment of the sixth embodiment of the present invention. FIG. 19 is a schematic flowchart of the operation method of the display device according to the seventh embodiment of the present invention.

1a: display surface

102: light source

104: LCD panel

104S: Glossy surface

106: light sensor

108: first electrode layer

108E1: first electrode

110: liquid crystal layer

110L: liquid crystal molecules

112: second electrode layer

112E: second electrode

114: third electrode layer

116: insulating layer

118: The first substrate

120: thin film transistor layer

122: color filter layer

122a: The first color filter

122b: second color filter

122c: third color filter

124: black matrix layer

126: second substrate

128, 132: Adhesive layer

130: upper polarizer

134: Cover Board

FR: Fingerprint recognition area

L1, L2: light

L3: reflected light

OP, 124a: opening

SL: slit

TD: Looking down direction

F: Finger

A-A’: Sectional line

Claims (21)

A display device for detecting a fingerprint of a finger, the display device has a display area, and the display device includes: A light source; A liquid crystal panel arranged on the light source, the liquid crystal panel including a first electrode layer, a liquid crystal layer and a second electrode layer, and the liquid crystal layer is arranged between the first electrode layer and the second electrode layer, Wherein the first electrode layer includes at least one first electrode disposed in the display area, and the at least one first electrode has a plurality of openings; and The plurality of light sensors respectively correspond to one of the plurality of openings. The display device according to claim 1, wherein the plurality of light sensors are disposed in the liquid crystal panel, the second electrode layer is disposed between the light source and the liquid crystal layer, and the liquid crystal panel further includes a third electrode Layer, and the second electrode layer is disposed between the liquid crystal layer and the third electrode layer, wherein the second electrode layer includes a plurality of second electrodes, and each of the second electrodes has at least one slit. The third electrode layer is exposed in a top view direction of the device. The display device according to claim 2, wherein the at least one first electrode overlaps a plurality of the second electrodes in the top view direction of the display device. The display device according to claim 2, wherein the liquid crystal panel further includes a plurality of first color filters, a plurality of second color filters, and a plurality of third color filters, which are disposed on the first electrode layer And each of the openings respectively corresponds to one of the plurality of first color filters, the plurality of second color filters, or the plurality of third color filters in the top view direction of the display device. The display device according to claim 4, wherein the plurality of light sensors are disposed between the plurality of second color filters and the at least one first electrode. The display device according to claim 1, wherein the first electrode layer further includes a plurality of third electrodes disposed in the display area, and each of the third electrodes does not have an opening, corresponding to the plurality of third electrodes The display area does not have a fingerprint recognition function. The display device according to claim 1, wherein the liquid crystal panel further includes a thin film transistor layer, and the plurality of light sensors are disposed between a black matrix layer and a second substrate, or the thin film transistor layer in. The display device according to claim 1, further comprising a liquid crystal display panel arranged between the light source and the liquid crystal panel, and the plurality of light sensors are arranged in the liquid crystal display panel. The display device according to claim 8, wherein the liquid crystal display panel includes a plurality of first color filters, a plurality of second color filters, and a plurality of third color filters, and each of the openings is in the display The top view direction of the device corresponds to one of the plurality of first color filters, the plurality of second color filters, or the plurality of third color filters. The display device according to claim 1, wherein the light source includes a self-luminous display panel, and the plurality of light sensors are arranged in the self-luminous display panel. The display device according to claim 10, wherein the self-luminous display panel includes a plurality of first light-emitting elements, a plurality of second light-emitting elements, and a plurality of third light-emitting elements, and each of the openings is in the top view direction of the display device It corresponds to one of the plurality of first light-emitting elements, the plurality of second light-emitting elements, or the plurality of third light-emitting elements. The display device according to claim 1, further comprising a liquid crystal display panel, the liquid crystal panel is arranged between the light source and the liquid crystal display panel, and the plurality of light sensors are arranged in the liquid crystal display panel. A display device for detecting a fingerprint of a finger. The display device has a display area. The display device includes: A liquid crystal display panel; A light source arranged under the liquid crystal display panel; A partial adjustment structure is disposed between the light source and the liquid crystal display panel. The partial adjustment structure includes a first electrode layer, a liquid crystal layer, and a second electrode layer. When the display device performs fingerprint recognition, the finger The display area that is close to or touched is a fingerprint recognition area, and the haze of the part of the local adjustment structure located in the fingerprint recognition area is less than the haze of the other part of the local adjustment structure located outside the fingerprint recognition area; as well as A plurality of light sensors are arranged in the display area of the liquid crystal display panel. The display device according to claim 13, wherein the first electrode layer includes a plurality of adjustment electrodes, and at least one of the plurality of adjustment electrodes is disposed in the display area. The display device according to claim 13, wherein the first electrode layer includes a plurality of first electrode stripes, the second electrode layer includes a plurality of second electrode stripes, and the plurality of first electrode stripes and the plurality of first electrode stripes The two electrode bars are staggered in a top view direction of the display device. The display device according to claim 13, wherein the liquid crystal layer comprises polymer dispersed liquid crystal, polymer network liquid crystal, or cholesteric liquid crystal. An operating method of a display device, wherein the display device includes a light source, a liquid crystal panel arranged on the light source, and a plurality of light sensors, the liquid crystal panel has a display area, and the plurality of light sensors are arranged at In the display area, the operation method includes: Enter a fingerprint recognition mode; When a finger approaches or touches the display area of the display device, the display area that the finger approaches or touches is determined as a fingerprint recognition area, and a fingerprint recognition step is performed, wherein the fingerprint recognition step includes: Adjust the liquid crystal molecules of the liquid crystal panel located in the fingerprint recognition area so that at least a part of the liquid crystal panel located in the fingerprint recognition area presents a light-transmitting state, and allows the light generated by the light source to pass through the at least part of the liquid crystal panel and emit Toward the finger, wherein the finger reflects the light as a reflected light; and Using the plurality of light sensors to detect the reflected light reflected from the finger to obtain a fingerprint image of the finger; and Determine whether the fingerprint image matches a fingerprint information. The operation method of the display device according to claim 17, wherein the display device further includes a touch element, and the operation method further includes, before performing the fingerprint recognition step, performing a touch detection step by using the touch element , To detect whether the finger is approaching or touching the display device, and when the display device determines that the finger is approaching or touching, the fingerprint identification step is performed. The operation method of the display device according to claim 18, further includes using the display device to display the position of the fingerprint recognition area before performing the touch detection step. The operating method of the display device according to claim 17, further comprising increasing the brightness of the light corresponding to the at least a part of the liquid crystal panel when adjusting the liquid crystal molecules. An integrated control chip is integrated in a display device. The display device includes a light source, a liquid crystal panel disposed on the light source, and a plurality of light sensors. The integrated control chip is used to control the light source, the liquid crystal panel, and the light sensor. A plurality of light sensors, the liquid crystal panel has a display area, and the plurality of light sensors are disposed in the display area, and the integrated control chip includes: A touch display control element for determining a fingerprint recognition area when a finger approaches or touches the display area in a fingerprint recognition mode; and A fingerprint recognition control element for performing a fingerprint recognition step in the fingerprint recognition mode, wherein the fingerprint recognition step includes: Adjust the liquid crystal molecules of the liquid crystal panel located in the fingerprint recognition area so that at least a part of the liquid crystal panel located in the fingerprint recognition area presents a light-transmitting state, and allows the light generated by the light source to pass through the at least part of the liquid crystal panel and emit Toward the finger, wherein the finger reflects the light as a reflected light; and The light sensors are used to detect the reflected light reflected from the finger to obtain a fingerprint image of the finger.

Images