Control circuit and display system and method for controlling display screen

Abstract

The present invention discloses a control circuit and a display system and a method for controlling a display screen. The control circuit is coupled to a system processor and a display screen, and the control circuit includes a touch control circuit, a display control circuit and a fingerprint control circuit. The touch control circuit is used to detect a finger touch on the display screen. The display control circuit is used to control the display screen to display at least one light spot to indicate a position touched by the finger. The fingerprint control circuit is used to perform fingerprint sensing through at least one fingerprint sensor corresponding to the position touched by the finger, and send fingerprint image data to the system processor, wherein the fingerprint image data corresponds to the sensing signal received from the at least one fingerprint sensor. Each of the above steps is performed by the control circuit when a display part of the system processor is maintained in a sleep state.

Description

Technical Field

[0001] The present invention relates to a method for controlling a display screen and a control circuit thereof, and in particular to a control circuit capable of executing a dark screen fingerprint unlocking function to unlock the display screen according to fingerprint recognition. Background Art

[0002] Fingerprint recognition technology has been widely used in a variety of electronic products, such as mobile phones, laptops, tablet computers, personal digital assistants, and portable electronic devices, to achieve identity recognition. Fingerprint sensing can easily identify users. Users only need to place their fingers on the fingerprint sensing panel or area to log in to the electronic device without having to enter a long and cumbersome user name and password.

[0003] Traditionally, if a user wants to wake up an electronic device (such as a mobile phone) from dark screen mode, the user can do so by double-clocking the screen or by any similar touch gesture. If the screen is locked and fingerprint recognition is required to unlock it, the touch sensing operation must be combined with the fingerprint recognition function, and the unlocking operation is more complicated. For example, the fingerprint control circuit needs to communicate with the system processor to determine and compare fingerprint features, so the user must move the finger to a predetermined position on the display screen to read the sensing signal. These redundant operations take extra time, resulting in a decrease in sensing speed, thereby reducing the user experience of fingerprint unlocking. Therefore, it is necessary to improve various aspects of the fingerprint unlocking process, such as unlocking speed and user experience. Summary of the invention

[0004] Therefore, the main purpose of the present invention is to provide a method for controlling a display screen and its related control circuit and display system, which can improve various aspects of the fingerprint unlocking process.

[0005] One embodiment of the present invention discloses a control circuit that can be coupled to a system processor and a display screen. The control circuit includes a touch control circuit, a display control circuit, and a fingerprint control circuit. The touch control circuit can be used to detect a finger touch on the display screen. The display control circuit can be used to control the display screen to display at least one light spot, and the at least one light spot indicates a position touched by the finger. The fingerprint control circuit can be used to perform fingerprint sensing through at least one fingerprint sensor corresponding to the position touched by the finger, and send fingerprint image data to the system processor, wherein the fingerprint image data corresponds to the sensing signal received from the at least one fingerprint sensor. Each of the above steps can be performed by the control circuit when a display portion of the system processor is maintained in a sleep state.

[0006] Another embodiment of the present invention discloses a method for controlling a display screen, for a control circuit. The control circuit is coupled to a system processor. The method includes the following steps: detecting a finger touch on the display screen; controlling the display screen to display at least one light spot, the at least one light spot indicating a position touched by the finger; performing fingerprint sensing by at least one fingerprint sensor corresponding to the position touched by the finger; and sending fingerprint image data to the system processor, wherein the fingerprint image data corresponds to a sensing signal received from the at least one fingerprint sensor. Each of the above steps can be performed by the control circuit when a display portion of the system processor is maintained in a sleep state.

[0007] Another embodiment of the present invention discloses a display system, which includes a display screen, a system processor and a control circuit. The control circuit can be coupled to the system processor and can be used to control the display screen. The control circuit can be used to: detect a finger touch on the display screen; control the display screen to display at least one light spot, the at least one light spot indicating a position touched by the finger; perform fingerprint sensing through at least one fingerprint sensor corresponding to the position touched by the finger, and send fingerprint image data to the system processor, wherein the fingerprint image data corresponds to the sensing signal received from the at least one fingerprint sensor. Each of the above steps can be performed by the control circuit when a display portion of the system processor is maintained in a sleep state.

[0008] Another embodiment of the present invention provides a control circuit that can be coupled to a system processor and a display screen. The control circuit includes a touch control circuit, a display control circuit, and a fingerprint control circuit. The touch control circuit can be used to detect a finger touch on the display screen. The display control circuit can be used to control the display screen to display at least one light spot without the intervention of a display portion of the system processor, and the at least one light spot indicates a position touched by the finger. The fingerprint control circuit can be used to perform fingerprint sensing through at least one fingerprint sensor corresponding to the position touched by the finger, and send fingerprint image data to the system processor, wherein the fingerprint image data corresponds to the sensing signal received from the at least one fingerprint sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 The figure shows a fingerprint unlocking process with the screen on.

[0010] Figure 2 A schematic diagram of a screen unlocking method based on fingerprint recognition according to an embodiment of the present invention.

[0011] Figure 3 A comparison of the timing relationship between a bright screen fingerprint unlocking process and a dark screen fingerprint unlocking process in an embodiment of the present invention is shown.

[0012] Figure 4 The figure is a flow chart of the fingerprint unlocking process according to the first embodiment of the present invention.

[0013] Figure 5 The implementation and operation of the fingerprint touch display integrated circuit according to the embodiment of the present invention are shown.

[0014] Figure 6 It is a schematic diagram of determining the validity of a finger touch according to a touch gesture according to an embodiment of the present invention.

[0015] Figure 7 A timing diagram during dark screen fingerprint sensing according to an embodiment of the present invention is shown.

[0016] Figure 8 It is a schematic diagram showing that the display control circuit and the fingerprint control circuit operate according to the image information from the touch control circuit according to an embodiment of the present invention.

[0017] Fig. 9 The state of the fingerprint touch display integrated circuit during the dark screen fingerprint sensing period of an embodiment of the present invention is shown.

[0018] Fig.10 Another timing diagram showing the operation of the display system according to an embodiment of the present invention is shown.

[0019] Fig.11 The implementation and operation of the fingerprint touch display integrated circuit for an organic light emitting diode display screen according to an embodiment of the present invention are shown.

[0020] Fig.12 This is a timing diagram during dark screen fingerprint unlocking according to Embodiment 1 of the present invention.

[0021] Fig.13 The details of the scenario in which the finger touches the display screen during fingerprint sensing according to an embodiment of the present invention are shown.

[0022] Figures 14 to 18 This is a timing diagram during dark screen fingerprint unlocking according to Embodiment 1 of the present invention.

[0023] Fig.19 Schematic diagram of the status of the fingerprint touch display integrated circuit during the dark screen fingerprint unlocking period of an embodiment of the present invention.

[0024] Figures 20-23 The present invention provides a flowchart of the dark screen fingerprint unlocking process according to an embodiment of the present invention.

[0025] The reference numerals are described as follows:

[0026] 40 Fingerprint unlocking process

[0027] Steps 400-410

[0028] 50 Display System

[0029] 500 System Processor

[0030] 502 Fingerprint Touch Display Integrated Circuit

[0031] 504 Display

[0032] 512 Display section

[0033] 514 Fingerprint part

[0034] 522 Touch Control Circuit

[0035] 524 Display Control Circuit

[0036] 526 Fingerprint Control Circuit

[0037] 530 Backlight

[0038] BL_EN Backlight enable signal

[0039] BR_PWM brightness control signal

[0040] 200, 210, 220, 230 Dark screen fingerprint unlocking process

[0041] 2002~2026、2102~2126、 Steps

[0042] 2202~2226、2302~2326 DETAILED DESCRIPTION

[0043] In order to improve the convenience of fingerprint recognition, the control circuit of the present invention and its related display system and method can be used to execute a dark screen fingerprint unlocking process, which can be executed when a display part of the system processor is maintained in a sleep state.

[0044] In some embodiments, fingerprint recognition can be performed when the screen (or display) of the electronic device is in a dark screen state (which is different from the Always-On Display (AOD) operation) and at least one finger is in contact with the screen. If the recognition is successful, the screen can be lit to display the recognition result or any instructions about unlocking, and then a user interface (UI) can be displayed to interact with the user.

[0045] In some embodiments, a larger area or even all areas on the display screen can be used to sense the fingerprint of the finger. In this embodiment, the control circuit can use the touch position of the finger to determine the position of sensing the fingerprint of the finger.

[0046] Since the screen does not need to be turned on to start the fingerprint sensing operation, and / or the finger only needs to touch the screen once during the fingerprint sensing operation without leaving the screen, the overall fingerprint recognition time can be shortened, thereby greatly improving the user experience.

[0047] In some embodiments, fingerprint signals can be sensed at the finger touch position of the screen (or display screen). To achieve this purpose, a sensor array can be set inside or below the display screen. The sensor array can be implemented by one or more sensing pixels, wherein each sensing pixel has at least one photodiode for sensing light and generating a sensing signal, and at least one transistor for transmitting the sensing signal to a control circuit. In this example, a photodiode can be used to sense light reflected by the finger to implement an optical fingerprint sensing operation.

[0048] Generally speaking, for a display device having both touch and fingerprint sensing functions, the control circuit used to process its touch sensing and fingerprint sensing operations may be a fingerprint touch display integration (FTDI) circuit. In one embodiment, the fingerprint touch display integration circuit may be implemented as an integrated circuit integrated in a single chip. Alternatively, the fingerprint touch display integration circuit may also be a combination of multiple chips, each chip having a control circuit with different functions. For ease of explanation, the control circuits hereinafter are referred to as "fingerprint touch display integration circuits".

[0049] Generally speaking, a display screen has a screen equipped with a touch sensor and a fingerprint sensor to have the sensing function of touch signal and fingerprint signal. A control circuit can be used to control the display driving, touch sensing and fingerprint sensing functions on the display screen. Figure 1 The figure shows a fingerprint unlocking process with the screen lit up, in which the display function can be disabled to save power when the display is in sleep mode or standby mode. If a finger touches the screen, the touch sensing part of the control circuit can notify the system processor of the finger touch information, and the system processor can light up the screen accordingly and send image data to control the screen to display an icon to indicate the designated location where the fingerprint image can be received.

[0050] In addition, since the system processor takes over the display control after receiving the information of the finger touch, the system processor can reset and restart the operation of the control circuit. During the reset or restart process, the touch sensing part can re-establish the calibration baseline when restarting the touch sensing operation to eliminate the background noise on the touch sensor. In this case, if the finger remains on the screen during the reset or restart process, the touch information of the finger may be regarded as background noise and filtered out, resulting in the control circuit being unable to successfully obtain the fingerprint information.

[0051] Therefore, when the display function of the display screen is awakened, the finger needs to leave the touch screen to correct the touch. In this case, the user needs to move the finger away from the touch screen and then put it back to the designated position on the touch screen to perform fingerprint sensing. The above redundant actions and time reduce the user experience of fingerprint recognition. In addition, because the system processor needs to send an image signal to the display screen to display an icon indicating the location where the fingerprint signal is received, more power consumption is required to achieve this display operation.

[0052] Please refer to Figure 2 , Figure 2 FIG. 1 is a schematic diagram of a screen unlocking method based on fingerprint recognition according to an embodiment of the present invention. Figure 2 As shown, the mobile phone was originally in a dark screen, and the system processor did not transmit any image to the fingerprint touch display integrated circuit to drive the panel to display the image. Therefore, a display part of the system processor can be in a sleep state. When the panel is awakened by detecting a finger touch, fingerprint sensing and identification can be started to achieve fingerprint unlocking. The fingerprint sensing function of the panel allows the user to place a finger on any position of the touch screen, and the fingerprint sensor set at the touch position can start fingerprint sensing. When the fingerprint recognition is successfully completed, the panel can be lit to display the information of successful recognition or successful unlocking, and then enter the home page or any appropriate user interface according to the design requirements. In other words, when the recognition is successful, the display part of the system processor will no longer be in a sleep state. Conversely, if the recognition fails, the panel can display information about the unlocking failure, or remain in a dark screen state.

[0053] The embodiment of the present invention adopts a dark screen fingerprint unlocking operation, and the fingerprint touch display integrated circuit can use the internal clock for display (i.e., internal frequency display) to maintain the dark screen and display at least one light spot when the display part of the system processor is maintained in a sleep state. At least one light spot can be used as a light source for optical fingerprint sensing, and the fingerprint touch display integrated circuit can determine the light spot position and / or more image information according to the position of the finger touch. Therefore, during the dark screen fingerprint unlocking period, the display function of the system processor can be disabled or turned off. In other words, the operation of sweeping black and light spot display can be controlled by the fingerprint touch display integrated circuit without the intervention of the system processor. Then, based on the fingerprint image from the fingerprint touch display integrated circuit, the system processor can start fingerprint recognition. It should be noted that in different embodiments, the fingerprint part of the system processor can be awakened or notified by the fingerprint touch display integrated circuit before the fingerprint sensing starts, after the fingerprint sensing is completed, or before the fingerprint sensing is completed.

[0054] In the above dark screen fingerprint unlocking process, the fingerprint touch display integrated circuit does not require the finger to leave the screen to sense the finger touch, which is different from the bright screen fingerprint unlocking process, which requires the finger to leave the screen to detect fingerprint and touch events. Figure 1 For the optical fingerprint unlocking solution under the bright screen, the overall fingerprint sensing and recognition process in the dark screen fingerprint unlocking process is faster and more convenient, and can achieve a better user experience.

[0055] Figure 3 A comparison of the timing relationship between a bright screen fingerprint unlocking process and a dark screen fingerprint unlocking process in an embodiment of the present invention is shown.

[0056] Figure 3 The upper part shows the process of unlocking the fingerprint with the screen on. First, the control circuit operates in a low power wakeup gesture (LPWG) mode, in which a touch control circuit in the control circuit periodically performs touch sensing operations, and the display control and fingerprint sensing functions of the control circuit are disabled. At this time, no image is displayed to achieve the purpose of saving power. When a finger touch is detected on the screen and the touch is judged to be valid, the touch control circuit can wake up a system processor and send the position information of the finger touch to the system processor. At the same time, the control circuit also starts a display resume sequence (meaning a reset and sleep exit procedure) as a recovery, restart or power-on procedure for entering the normal display mode. In the normal display mode, the display screen can be displayed normally according to the image information from the system processor (such as received through the Mobile Industry Processor Interface (MIPI)). At this time, the display part of the system processor will no longer be in a sleep state.

[0057] It is worth noting that in the display recovery procedure, the touch control circuit can perform baseline correction for touch operations. Therefore, the finger needs to leave the screen briefly to avoid the finger position information being filtered out during the correction process, so that the fingerprint and touch events can be detected. Next, the finger can return to the screen, and the touch control circuit detects the finger touch (that is, correctly obtains the finger position information (such as coordinate information)), thereby notifying the fingerprint control circuit to start fingerprint sensing according to the touch position. Then, based on the image data obtained by the fingerprint control circuit through fingerprint sensing, the system processor can start fingerprint recognition. When the system processor determines that the fingerprint recognition is successful through the relevant algorithm, it can control the display screen to unlock the screen and display appropriate information (such as displaying the home page).

[0058] Figure 3The lower part shows the dark screen fingerprint unlocking process of some embodiments of the present invention, which is simpler than the bright screen process. In the low-power wake-up gesture mode, the panel does not display any image, and only touch sensing is performed periodically in the dark screen. When a finger touch is detected on the touch screen and the touch is determined to be valid, the touch control circuit in the fingerprint touch display integrated circuit can notify the fingerprint control circuit in the fingerprint touch display integrated circuit to perform fingerprint sensing, and transmit relevant information such as the coordinate (position) information of the finger to the fingerprint control circuit in the fingerprint touch display integrated circuit. After the fingerprint control circuit in the fingerprint touch display integrated circuit completes the fingerprint sensing, it can send the fingerprint image data to the system processor, and the system processor can perform fingerprint recognition based on the received fingerprint image data through relevant algorithms. Then, if the fingerprint recognition indicates a successful result, the fingerprint touch display integrated circuit can start to execute the display recovery program to wake up the display part of the system processor, which can control the display screen to unlock and display normally (i.e. enter the bright screen mode). Therefore, during the fingerprint unlocking process of this embodiment, the finger can stay on the touch screen continuously, which can achieve a better user experience. It should be noted that the display recovery procedure may also be started earlier or even removed, and the subsequent embodiments will provide detailed descriptions.

[0059] Please refer to Figure 4 , Figure 4 4 is a flow chart of a fingerprint unlocking process 40 according to an embodiment of the present invention. The fingerprint unlocking process 40 can be implemented by a control circuit (such as a fingerprint touch display integrated circuit), which is coupled to a system processor and used to control a display screen with touch and fingerprint sensing functions. Figure 4 As shown, the fingerprint unlocking process 40 includes the following steps:

[0060] Step 400: Start.

[0061] Step 402: When the display portion of the system processor remains in the sleep state, detect a finger touch on the display screen.

[0062] Step 404: When the display portion of the system processor is maintained in a sleep state, control the display screen to display at least one light spot, the at least one light spot indicating the position touched by the finger. Step 406: When the display portion of the system processor is maintained in a sleep state, perform fingerprint sensing through at least one fingerprint sensor corresponding to the position touched by the finger.

[0063] Step 408: When the display portion of the system processor is maintained in the sleep state, send fingerprint image data to the system processor, wherein the fingerprint image data corresponds to the sensing signal received from at least one fingerprint sensor.

[0064] Step 410: End.

[0065] According to the fingerprint unlocking process 40, the touch control circuit may first detect the finger touch on the display screen, which may be achieved through the aforementioned low-power wake-up gesture operation, wherein the finger touch may be detected in the dark screen mode without displaying any image to save power consumption. After the touch control circuit detects the finger touch, the fingerprint control circuit and the display control circuit in the fingerprint touch display integrated circuit may be awakened. The display control circuit thus controls the display screen to display a light spot to indicate the position of the finger touch, and the light spot may be used to provide the light source required for exposure, and the light emitted by the light spot is reflected by the finger to realize optical fingerprint sensing. The fingerprint control circuit thus performs fingerprint sensing through at least one fingerprint sensor at the corresponding position of the finger touch, wherein the fingerprint sensor disposed below the touch position may be enabled to sense the reflected light. After receiving the sensing signal from the fingerprint sensor, the fingerprint control circuit may convert the sensing signal into corresponding digital data and transmit it to the system processor. It should be noted that each of the above steps may be performed by the fingerprint touch display integrated circuit while the display portion of the system processor is maintained in a sleep state. That is to say, before the fingerprint control circuit completes fingerprint sensing, the display part of the system processor can be maintained in a sleep state, that is, during the fingerprint unlocking process, the fingerprint touch display integrated circuit does not need to receive any image information related to the light spot or other displayed images from the system processor. The image information related to at least one light spot may include the location information of at least one light spot. The image information related to at least one light spot may also include other image information, such as the size, brightness, shape, pattern, etc. of at least one light spot. The image information related to at least one light spot can be determined by the fingerprint touch display integrated circuit, for example, by the touch control circuit and / or the display control circuit.

[0066] Figure 5 The details of the implementation and operation of the fingerprint touch display integrated circuit according to the embodiment of the present invention are shown. Figure 5As shown, a display system 50 includes a system processor 500, a fingerprint touch display integrated circuit 502 and a display screen 504. The system processor 500 can be used to provide image data to be displayed on the display screen 504, and provide fingerprint recognition function. More specifically, the system processor 500 includes a display part 512 and a fingerprint part 514. The display part 512 can be used to provide image data to the fingerprint touch display integrated circuit 502 to control the fingerprint touch display integrated circuit 502 to display according to the image data; the fingerprint part 514 performs fingerprint recognition based on the fingerprint image data from the fingerprint touch display integrated circuit 502 (such as through a trust zone). The display part 512 can send image data to the fingerprint touch display integrated circuit 502 through a mobile industry processor interface. The fingerprint part 514 can communicate with the fingerprint touch display integrated circuit 502 through another interface (such as a serial peripheral interface (SPI)).

[0067] The fingerprint touch display integrated circuit 502 is coupled between the system processor 500 and the display screen 504, and can be used to control the touch sensing, fingerprint sensing and image display functions of the display screen 504. More specifically, the fingerprint touch display integrated circuit 502 includes a touch control circuit 522, a display control circuit 524 and a fingerprint control circuit 526. The touch control circuit 522 can be used to perform touch sensing on the display screen 504, and this display screen 504 can be a touch display screen with fingerprint sensing function. In one embodiment, the touch control circuit 522 has the aforementioned low-power wake-up gesture function, which can be used to detect finger touch in dark screen mode to wake up the display screen 504 and related display functions. The display control circuit 524 can control the display operation on the display screen 504 by outputting image signals and scanning gate lines. The fingerprint control circuit 526 can be used to perform fingerprint sensing on the display screen 504. The fingerprint control circuit 526 may receive a sensing signal through at least one fingerprint sensor disposed inside or below the display screen 504 (or disposed together with the display screen 504 in any manner), and correspondingly send fingerprint image data to the fingerprint portion 514 of the system processor 500 for fingerprint recognition.

[0068] In this example, the display screen 504 may be a liquid crystal display (LCD), which includes a backlight source 530 for generating the backlight required for display. The backlight source 530 may be controlled by the display control circuit 524 in the fingerprint touch display integrated circuit 502. In the dark screen fingerprint unlocking process of the present invention, the display control circuit 524 may control the operation of the backlight source 530 without receiving the instruction of the system processor 500 (especially the display portion 512 of the system processor 500). More specifically, unlike the display function on the existing liquid crystal display screen that can only be enabled and controlled by the system processor, in the embodiment of the present invention, the display control circuit 524 in the fingerprint touch display integrated circuit 502 may control and enable the backlight source 530 for display operation. Therefore, in the display screen 504, a light spot may be displayed when the display portion 512 of the system processor 500 is not enabled. Since the display portion 512 of the system processor 500 is maintained in a sleep and power saving state, the fingerprint unlocking process may be regarded as being performed in a dark screen mode, and is therefore referred to as dark screen fingerprint unlocking.

[0069] Please continue to refer to Figure 5 , the touch control circuit 522 can be set to have several detection modes, including 1-dimensional (1D) scanning mode, 2-dimensional (2D) scanning mode, and validity detection. The 1D scanning mode and the 2D scanning mode can be regarded as low-power wake-up gesture modes. In the 1D scanning mode, a 1D touch scan can be performed to determine whether a finger touch exists. If no finger touch is detected on the touch screen, the 1D touch scan can be continuously performed periodically. The 1D touch scan represents a scan used to detect whether there is a touch on the touch screen of the display screen 504 without obtaining detailed information about the finger touch (such as coordinate points). Therefore, since the system only detects whether there is a finger touch and does not consume power to calculate the detailed information of the finger touch, lower power consumption can be achieved. For example, multiple touch sensors within a larger range can be used for simultaneous sensing to detect whether a finger touch exists, regardless of the location of the finger touch.

[0070] When the touch control circuit 522 detects a finger touch on the display screen 504, it can start to perform a 2D touch scan to detect and determine more detailed information, such as the location of the finger touch (such as a coordinate point). In the 2D scanning mode, the coordinates and / or radius of the finger touch can be determined. For example, under the capacitive touch sensing scheme, the capacitance values ​​of several sensing electrodes near the finger touch area can be obtained to calculate the radius of the touch area and the coordinates of the finger touch. Compared with the 1D scanning mode that only detects whether a touch occurs on the screen, the determination of detailed information about the finger touch in the 2D scanning mode requires more power consumption.

[0071] According to the image information of the finger touch, the touch control circuit 522 can determine whether the finger touch is valid, and thus determine whether the fingerprint control circuit 526 should be notified to start fingerprint sensing. In one embodiment, whether the touch is valid can be determined based on the touch sensing area and / or touch signal strength of the finger touch. For example, if the radius, area and / or range of the touch sensing area is greater than a predetermined critical value, the finger touch can be determined as a valid touch event; and / or if the maximum touch sensing signal, overall sense measurement and / or finger contact time is greater than a predetermined critical value, the finger touch can be determined as a valid touch event.

[0072] Alternatively or additionally, the touch control circuit 522 may also determine the validity of the finger touch according to a predetermined touch gesture. Figure 6 , Figure 6 Schematic diagram of determining the validity of a finger touch according to a touch gesture according to an embodiment of the present invention. The touch control circuit 522 can be configured to use one or more touch gestures to trigger the dark screen fingerprint unlocking process to notify the display control circuit 524 to display the light spot and notify the fingerprint control circuit 526 to start fingerprint sensing. Figure 6 When the Z-shaped touch gesture shown in the figure matches, the finger touch can be judged to be valid. The validity detection related to the specific touch gesture can avoid the wrong start of the dark screen fingerprint unlocking due to the accidental touch. Figure 6 In the illustrated embodiment, if the finger touch matches the Z-shaped touch gesture, the touch control circuit 522 may decide to start the dark screen fingerprint unlocking process. At this time, the display control circuit 524 and the fingerprint control circuit 526 may start operations such as light spot display and fingerprint sensing at the coordinate point of the finger's last position.

[0073] In the embodiment of the present invention, the touch control circuit 522 may determine the validity of the finger touch based on various touch behaviors, which shall not limit the scope of the present invention.

[0074] If the finger touch passes the validity detection, the touch control circuit 522 can wake up or notify the display control circuit 524 to display the light spot, and wake up or notify the fingerprint control circuit 526 to perform fingerprint sensing. On the other hand, if the finger touch fails the validity detection, the touch control circuit 522 can return to the 1D or 2D scanning mode for touch detection.

[0075] Figure 7 FIG. 1 shows a timing diagram during dark screen fingerprint sensing in an embodiment of the present invention. Figure 7 Can be matched Figure 4 Also refer to. Figure 7As shown, the dark screen fingerprint sensing period may start with a sleep out sequence (used to exit the sleep mode) and end with a sleep in sequence (used to enter the sleep mode). When the fingerprint touch display integration circuit 502 determines that the finger touch is valid, the sleep exit sequence may be executed to wake up the display control circuit 524 and the fingerprint control circuit 526. Therefore, the display control circuit 524 may first clear the screen image and then start to display at least one light spot. In detail, the display control circuit 524 may receive image information such as the coordinate point and / or radius of the finger touch from the touch control circuit 522 to control the display screen 504 to display the light spot at an appropriate position, or even control the light spot to have an appropriate size, and other areas on the screen are scanned as black patterns.

[0076] It is worth noting that the display control circuit 524 can control the display screen 504 to display the light spot without receiving instructions from the system processor 500. Therefore, the display screen 504 only displays the light spot according to the image information from the display control circuit 524, wherein the image information may include the light spot position information determined according to the touch sensing result of the touch control circuit 522 and / or the light spot image information predefined by the fingerprint touch display integration circuit 502. In the absence of intervention by the system processor 500, the display control circuit 524 can control the light spot display and black scanning through an internal clock of the fingerprint touch display integration circuit 502. The internal clock can be used to coordinate and synchronize the operations of the touch control circuit 522, the display control circuit 524 and the fingerprint control circuit 526 to achieve time-sharing control between the display, touch and fingerprint sensing functions, such as Figure 7 As shown, in this way, the display portion 512 of the system processor 500 can be maintained in the sleep state.

[0077] In this example, the display screen 504 may be a liquid crystal display screen, which may display images according to the light emitted by the backlight source 530. In some embodiments, the display control circuit 524 may control the backlight source 530 to display at least one appropriate light spot. Specifically, the display control circuit 524 may send a backlight enable signal BL_EN to enable the backlight source 530, wherein the backlight enable signal BL_EN may be implemented using a two-state control port, such as Figure 7As shown. In order to enable optical fingerprint sensing based on light spot exposure to proceed smoothly, the display control circuit 524 can also send a brightness control signal BR_PWM to the backlight source 530 to fully turn on the backlight source 530 to display the maximum brightness. The maximum brightness can maximize the fingerprint peak to valley information carried by the sensing signal. It should be noted that the setting of the maximum brightness is only one of the many embodiments of the present invention, and the brightness can be flexibly controlled according to system requirements. For example, in order to improve the visual effect during fingerprint sensing, the light emission of the backlight source 530 can be slowly turned on / off by dimming. In an embodiment of the present invention, the display control circuit 524 should be able to control the operation of the backlight source 530 without the intervention of the system processor 500. In this way, the display portion 512 of the system processor 500 can be maintained in a sleep state.

[0078] During the light spot display period, the touch control circuit 522 can selectively perform touch sensing to determine whether the finger is still on the touch screen. In addition, one or more skip frames can be inserted during the display period for fingerprint sensing, that is, the display and fingerprint sensing operations can be performed in time to avoid mutual interference. In general, the fingerprint sensing operation can be divided into reset and selection steps (also including exposure steps), which can be allocated to each skip frame in an appropriate manner. The detailed operation of fingerprint sensing should be well known to those skilled in the art and will not be repeated here. The timing relationship between the display period and the fingerprint sensing period can be well controlled by the internal clock of the fingerprint touch display integration circuit 502.

[0079] As described above, the touch control circuit 522 can provide finger touch information to the display control circuit 524 so that the display control circuit 524 can control the display of the light spot. The touch control circuit 522 can also provide finger touch information to the fingerprint control circuit 526 so that the fingerprint control circuit 526 can perform fingerprint sensing. Figure 8 An embodiment in which the display control circuit 524 and the fingerprint control circuit 526 operate according to the image information from the touch control circuit 522 is shown. In this example, the fingerprint sensor disposed inside or below the display screen 504 or disposed together with the display screen 504 in any manner can be defined as having multiple areas. The image information provided by the touch control circuit 522 can indicate that the fingerprint sensor corresponding to one or more areas covered by the finger touch position should be turned on, started, or notified to perform fingerprint sensing and generate a fingerprint sensing signal. Correspondingly, the display control circuit 524 can control the display screen 504 to display a light spot at the touch position for exposure. Furthermore, the size of the light spot can also correspond to the radius or area of ​​the finger touch detected by the touch control circuit 522. At the same time, the display control circuit 524 can sweep black (i.e., display a black image) in other areas on the screen where no touch event is detected.

[0080] Fig. 9 The state of the fingerprint touch display integration circuit 502 during the dark screen fingerprint sensing period of an embodiment of the present invention is shown. When the touch control circuit 522 detects a finger touch and determines that the finger touch is valid, that is, when the dark screen fingerprint sensing period begins, the display control circuit 524 and the fingerprint control circuit 526 in the fingerprint touch display integration circuit 502 both execute the exit sleep program to leave the sleep mode. Then, during the display period, the display control circuit 524 can perform display operations such as display spots and black-out of other areas on the screen through the internal clock, and can preferably set the luminous intensity of the backlight source 530 to the maximum, and selectively adopt a dimming mechanism. The fingerprint control circuit 526 can perform fingerprint sensing in the frame skipping. In another embodiment, more frame skipping can also be set during the dark screen fingerprint sensing period, and dimming can be flexibly performed on each display frame. The frame skipping can be distributed between each display frame during the dark screen fingerprint sensing period or concentrated at any time point. The operation of the fingerprint control circuit 526 can be synchronized with the operation of the display control circuit 524 to perform fingerprint sensing on the allocated frame skipping during the dark screen fingerprint sensing period. After the fingerprint control circuit 526 completes the fingerprint sensing, it may send the fingerprint image data to the system processor 500 .

[0081] In some embodiments, the fingerprint control circuit 526 in the fingerprint touch display integrated circuit 502 can provide an interrupt signal to the system processor 500 to wake up the system processor 500 to perform fingerprint recognition and execute corresponding steps. For example, the fingerprint control circuit 526 can provide an interrupt signal to wake up the fingerprint part 514 of the system processor 500 after the fingerprint sensing is completed. Alternatively, the fingerprint control circuit 526 can also provide an interrupt signal to wake up the fingerprint part 514 of the system processor 500 before the end time of the fingerprint sensing. Therefore, the fingerprint part 514 can start to receive fingerprint image data from the fingerprint control circuit 526 when the fingerprint sensing is completed, and the fingerprint part 514 can then start fingerprint recognition on the received fingerprint image data. In one embodiment, the fingerprint control circuit 526 can even provide an interrupt signal to wake up the fingerprint part 514 before the start time of the fingerprint sensing. For example, if Fig. 9 As shown, before the fingerprint control circuit 526 starts to perform fingerprint sensing, an interrupt signal may be sent to wake up the fingerprint part 514 when executing the exit sleep procedure.

[0082] It is worth noting that in the embodiment where the fingerprint control circuit 526 sends an interrupt signal to wake up the fingerprint part 514 before the fingerprint sensing starts, the fingerprint control circuit 526 can perform fingerprint sensing according to the instruction of the system processor 500. That is, after the trust zone of the fingerprint part 514 is awakened, the fingerprint part 514 can send a command to the fingerprint touch display integrated circuit 502 to instruct the fingerprint control circuit 526 whether to start fingerprint sensing. In this way, the system processor 500 can be used to determine whether to enable the fingerprint sensing function of the fingerprint touch display integrated circuit 502. In this way, the fingerprint control circuit 526 starts to perform fingerprint sensing through the fingerprint sensor only after receiving the permission of the system processor 500. In other words, when the permission of the system processor 500 is not received, the fingerprint touch display integrated circuit 502 is not allowed to automatically capture the fingerprint image, which can improve the security of the display system 50.

[0083] Alternatively, in an embodiment where the fingerprint control circuit 526 sends an interrupt signal to wake up the fingerprint portion 514 before fingerprint sensing begins, the fingerprint control circuit 526 may also perform fingerprint sensing after receiving a notification from the touch control circuit 522 but without receiving permission from the system processor 500.

[0084] It is worth noting that the interrupt signal transmitted when executing the exit sleep program is only used to wake up the fingerprint part 514 of the system processor 500, such as the trust zone and its related identification module. At this time, the display part 512 of the system processor 500 is still not awakened and remains in the sleep state, and the related display interface (such as the mobile industry processor interface) does not transmit any display data. Therefore, the fingerprint touch display integrated circuit 502 can use the internal clock to control the display screen 504 to display the light spot without the intervention of the system processor 500.

[0085] Please continue to refer to Fig. 9 After the fingerprint control circuit 526 completes the fingerprint sensing and sends the fingerprint image data to the system processor 500, the fingerprint control circuit 526 and the display control circuit 524 can execute the sleep procedure and return to the sleep mode. Then, after the fingerprint recognition is completed, the display part 512 of the system processor 500 can be awakened to take over the display control of the display screen 504, such as displaying the success or failure of the fingerprint recognition.

[0086] Fig.10 Another timing diagram showing the operation of the display system 50 according to an embodiment of the present invention is shown. This timing diagram is a Chinese patent application 202010717624.0. Figure 7 An alternative to the timing diagram shown in Fig.10As shown, the fingerprint touch display integrated circuit 502 can send an interrupt signal to the system processor (AP) 500 at the start time of the fingerprint sensing operation to wake up the fingerprint part 514 of the system processor 500, which is earlier than the Chinese patent application No. 202010717624.0 Figure 7 The time of delivery is shown. Fig.10 For other implementations and operation methods, please refer to the description of Chinese patent application 202010717624.0, which will not be described in detail here.

[0087] In an alternative embodiment, after the fingerprint sensing is completed and the fingerprint image data is to be transmitted to the system processor 500, an interrupt signal may be sent or provided to the system processor 500, similar to the embodiment described in Chinese Patent Application No. 202010717624.0. In other words, in Chinese Patent Application No. 202010717624.0 Figure 7 The embodiment can also be used to implement the dark screen fingerprint unlocking process. In this case, the interrupt signal can be used to wake up the fingerprint part 514 of the system processor 500 to receive the upcoming fingerprint image data. In addition, the display part 512 of the system processor 500 can also be awakened to enter an awake state after the fingerprint sensing is completed. For example, the interrupt signal used to notify the system processor 500 to start performing fingerprint recognition based on fingerprint image data can also be used to wake up the display part 512 of the system processor 500. In this case, the fingerprint control circuit 526 can start to perform fingerprint sensing through the fingerprint sensor without receiving permission from the system processor 500.

[0088] It is worth noting that the above embodiments are used to illustrate the implementation methods of dark screen fingerprint unlocking operations that can be used for liquid crystal displays. However, the present invention can be applied to various types of display screens. For example, in another embodiment, the dark screen fingerprint unlocking operation can also be applied to another type of display screen, such as an organic light-emitting diode (OLED) display screen. Since the organic light-emitting diode display screen has the characteristic of self-luminescence, it does not require any backlight source. Therefore, the display control circuit 524 in the fingerprint touch display integration circuit 502 does not need to output any control signal to control the backlight source. Fig.11 The implementation and operation of the fingerprint touch display integrated circuit 502 for an organic light emitting diode display screen 504 according to an embodiment of the present invention are shown. Fig.11 As shown, since the display screen 504 does not include a backlight module, the fingerprint touch display integrated circuit 502 does not need to send a signal for controlling the backlight module. In addition, the fingerprint touch display integrated circuit 502 can send a brightness control signal (not shown) to the display screen 504 to control the brightness of the display screen 504. Fig.11 For other operations, please refer to the above Figure 5 The operating instructions are not repeated here.

[0089] Various embodiments of the present invention are described below using timing diagrams.

[0090] Please refer to Fig.12 , Fig.12 This is a timing diagram during dark screen fingerprint unlocking according to Embodiment 1 of the present invention. Fig.12 Used to illustrate the situation where fingerprint unlocking fails due to certain factors, it shows the operation of the fingerprint touch display integrated circuit (FTDI) 502 and the system processor (AP) 500. First, in the fingerprint touch display integrated circuit 502, the touch control circuit 522 first performs a 1D touch scan to detect whether there is a finger touch. At this time, the display control circuit 524 and the fingerprint control circuit 526 are both in sleep mode. When a touch is detected on the display screen 504, the touch control circuit 522 starts to perform a 2D touch scan to detect more information about the finger touch (such as touch position information). 1D and 2D touch scans can be performed in a low-power wake-up gesture mode. In some embodiments, a wake-up gesture can also be detected in a low-power sleep mode to determine whether the touch is valid, thereby starting fingerprint sensing. If the touch control circuit 522 determines that the finger touch is valid, the display control circuit 524 and the fingerprint control circuit 526 can be awakened to start dark screen fingerprint sensing. In different embodiments, the fingerprint control circuit 526 may send an interrupt signal to the system processor 500 at the beginning or end of the dark screen fingerprint sensing period to wake up the fingerprint part 514 of the system processor 500. Then, the fingerprint image data generated by the dark screen fingerprint sensing may be transmitted to the system processor 500, and the system processor 500 may perform fingerprint recognition on the received fingerprint image data.

[0091] In this case, the fingerprint recognition of the system processor 500 may indicate a failed result. In some embodiments, the system processor 500 does not enable its display portion 512, so that the display portion 512 remains in a sleep state. In this case, the display function may remain off, and the display screen 504 does not display the recognition failure result or any other image, and the display portion 512 of the system processor 500 may remain in a sleep state. At the same time, the display control circuit 524 and the fingerprint control circuit 526 in the fingerprint touch display integrated circuit 502 return to sleep mode, and the touch control circuit 522 may return to 1D or 2D scanning mode, and restart the low-power touch detection on the display screen 504.

[0092] As described above, during the dark screen fingerprint sensing period, the touch control circuit 522 can continuously and periodically monitor and determine whether the finger touch remains on the touch screen of the display screen 504. In one embodiment, when the touch control circuit 522 detects that the finger leaves the display screen 504, it can control the display control circuit 524 and the fingerprint control circuit 526 to return to the sleep mode. In this case, the display function also remains off, and the display screen 504 does not display any image.

[0093] Fig.13 Detailed description of the situation in which the finger touches and leaves the display screen 504 during the fingerprint sensing period according to the embodiment of the present invention is shown. Fig.13 As shown, the display control circuit 524 can control the display screen 504 to display a light spot for exposure, and the fingerprint control circuit 526 can perform fingerprint sensing (including reset and selection / writing) within a jump frame. While the display screen 504 displays the light spot, the touch control circuit 522 can periodically perform touch sensing. When the touch control circuit 522 detects that the finger leaves the touch screen of the display screen 504, the fingerprint control circuit 526 can stop performing dark screen fingerprint sensing and return to sleep mode or idle mode. At the same time, the display control circuit 524 can also stop displaying the light spot and execute a sleep program to enter sleep mode or idle mode. The touch control circuit 522 can also enter a 1D (or 2D) scanning mode. In this way, when the finger is removed from the touch screen, the fingerprint touch display integration circuit 502 does not need to perform unnecessary fingerprint sensing, and the system processor 500 does not need to perform unnecessary fingerprint recognition.

[0094] Please refer to Fig.14 , Fig.14 This is a timing diagram during dark screen fingerprint unlocking according to Embodiment 1 of the present invention. Fig.14 It is shown that after the fingerprint recognition is completed, the display screen 504 displays the fingerprint recognition result. Fig.14 As shown, no matter whether the fingerprint recognition succeeds or fails, the system processor 500 can wake up the display part 512 to start the normal display operation so as to perform normal display on the display screen 504 .

[0095] In this example, after the system processor 500 completes the fingerprint recognition based on the fingerprint image data from the fingerprint touch display integrated circuit 502, the display portion 512 can be awakened to enter an awake state, thereby controlling the display control circuit 524 and the display screen 504 to display the fingerprint recognition result. In detail, if the fingerprint recognition fails, the display screen 504 can display the recognition failure information; if the fingerprint recognition is successful, the display screen 504 can be successfully unlocked (such as displaying the home page). After the fingerprint touch display integrated circuit 502 completes the fingerprint sensing, it can execute the sleep program to return to the sleep mode or idle mode. Then, when the display portion 512 of the system processor 500 is transformed into the awake state, it can instruct the fingerprint touch display integrated circuit 502 to execute a display recovery program to start the normal display function. In this example, the display recovery program can be started after the fingerprint touch display integrated circuit 502 receives the notification of the system processor 500, and the fingerprint touch display integrated circuit 502 displays the corresponding fingerprint recognition result on the display screen 504.

[0096] Please refer to Fig.15 , Fig.15 This is a timing diagram of the dark screen fingerprint unlocking period in the first embodiment of the present invention. In order to shorten the time required for dark screen fingerprint sensing, the display recovery procedure can be started before the system processor 500 generates a fingerprint recognition result (success or failure), such as Fig.15 As shown. Preferably, the system processor 500 can be controlled to complete fingerprint recognition at the same time as the display recovery program is completed, so that after the system processor 500 completes the fingerprint recognition and generates the recognition result, it can immediately control the display control circuit 524 to output an image to display the fingerprint recognition result. In addition, in some embodiments, the fingerprint touch display integration circuit 502 can predict the time required to execute the display recovery program and the time required for the system processor 500 to complete the fingerprint recognition, and start the display recovery program in advance accordingly, that is, start a predetermined time before receiving the fingerprint recognition result. In this way, when the fingerprint touch display integration circuit 502 receives the fingerprint recognition result, the display recovery program can also be executed and completed at the same time.

[0097] In this example, while the system processor 500 calculates the fingerprint image data and performs matching related to fingerprint identification, the fingerprint touch display integrated circuit 502 also executes the display recovery program, and the display recovery program can be completed when the system processor 500 generates the fingerprint identification result and sends the fingerprint identification result to the fingerprint touch display integrated circuit 502. The simultaneous operation of the fingerprint touch display integrated circuit 502 and the system processor 500 can further save the time spent on dark screen fingerprint unlocking.

[0098] Please refer to Fig.16 , Fig.16 This is a timing diagram during dark screen fingerprint unlocking according to Embodiment 1 of the present invention. Fig.16 FIG. 5 shows a case where the fingerprint recognition performed based on the fingerprint image data of the dark screen fingerprint sensing indicates that the recognition fails. In this example, after the dark screen fingerprint sensing operation, the display part 512 of the system processor 500 can be awakened (i.e., enter the awake state), which can control the fingerprint touch display integration circuit 502 to start the display recovery procedure, thereby enabling normal display operation, similar to FIG. Fig.15 The situation shown. Then, after determining that the fingerprint recognition has failed, the fingerprint control circuit 526 in the fingerprint touch display integrated circuit 502 can also restart the fingerprint sensing (i.e., bright screen fingerprint sensing) when the display portion 512 is in the awake state. In this case, the display portion 512 can control the display operation to display light spots and black sweeps on the display screen 504. The fingerprint control circuit 526 can perform fingerprint sensing again and send fingerprint image data to the system processor 500. The fingerprint portion 514 of the system processor 500 can receive an interrupt signal from the fingerprint control circuit 526 and receive fingerprint image data accordingly, perform fingerprint recognition to determine the recognition result. Then, the display screen 504 can display the fingerprint recognition result (success or failure).

[0099] Please refer to Fig.17 , Fig.17 This is a timing diagram of the dark screen fingerprint unlocking period in the first embodiment of the present invention. Fig.17 As shown, after the first dark screen fingerprint sensing is completed and the fingerprint recognition indicates the result of recognition failure, the fingerprint touch display integrated circuit 502 returns to the sleep mode, and the touch control circuit 522 restarts to perform 1D touch scanning to detect whether there is a touch on the screen of the display screen 504. In this example, the touch control circuit 522 can detect that the finger is still placed on the screen, thereby entering a 2D scanning mode to detect the position of the finger touch on the display screen 504. If the touch control circuit 522 determines that the finger touch is valid, the fingerprint touch display integrated circuit 502 can restart the dark screen fingerprint sensing. If the fingerprint recognition is successful, the system processor 500 can instruct the fingerprint touch display integrated circuit 502 to start the display recovery program, so that the display screen 504 can enable normal display operation, such as displaying the home page after unlocking. In this example, the system processor 500 does not enable normal display operation before the fingerprint recognition is successful. Alternatively or additionally, when the recognition fails for more than a preset number of times, the display screen 504 can still enable normal display operation and display a user interface for the user to enter a password to unlock the screen.

[0100] When a general display system is powered on, a display recovery program can be executed to reset the system to start display operation. Figures 12 to 17In the embodiment of , after the fingerprint touch display integrated circuit 502 completes the dark screen fingerprint sensing operation, it can execute a sleep process to return to the sleep mode (for example, pull the working voltage to the ground potential), and then execute a display recovery process (for example, increase the working voltage to an appropriate potential) before the normal display operation. In this case, the sleep process plus the display recovery process wastes a lot of time. Fig.18 In the illustrated embodiment, the system does not need to execute the sleep procedure and the display recovery procedure, thereby saving at least hundreds of milliseconds of time.

[0101] Please refer to Fig.18 , Fig.18 This is a timing diagram of the dark screen fingerprint unlocking period in the first embodiment of the present invention. Fig.18 As shown, after the dark screen fingerprint sensing is completed, the fingerprint touch display integrated circuit 502 does not execute the sleep procedure to enter the sleep mode, and therefore does not need to execute the display recovery procedure. In this example, the display part 512 of the system processor 500 can be awakened after the fingerprint recognition is successful, and then the display part 512 can control the display control circuit 524 in the fingerprint touch display integrated circuit 502 to display the fingerprint recognition result without executing any display recovery procedure. Since the fingerprint touch display integrated circuit 502 is in the state of exiting the sleep mode during the dark screen fingerprint sensing period, its operating voltage (such as the gate voltage VGH / VGL) can be the same as the operating voltage in the bright screen display mode (i.e., the mode of receiving image data from the system processor 500 for display), therefore, the internal frequency display of the fingerprint touch display integrated circuit 502 can be seamlessly switched to the external frequency display processed by the system processor 500. In the external frequency display, the system processor 500 can send image data to the display control circuit 524 in the fingerprint touch display integrated circuit 502 through, for example, a mobile industry processor interface to display the image data on the display screen 504.

[0102] As described above, after the system processor 500 completes fingerprint recognition and obtains the corresponding recognition result, it should control the fingerprint touch display integrated circuit 502 to start the display recovery program. The display recovery program should be executed after the fingerprint touch display integrated circuit 502 completes the dark screen fingerprint sensing process and returns to the sleep mode. To achieve this purpose, the fingerprint touch display integrated circuit 502 can send an indication signal to the system processor 500 to indicate whether the fingerprint touch display integrated circuit 502 is in the sleep mode or the start mode.

[0103] Please refer to Fig.19 , Fig.19 FIG. 5 is a schematic diagram of the state of the fingerprint touch display integrated circuit 502 during the dark screen fingerprint unlocking period according to an embodiment of the present invention. Fig.19As shown, when a valid finger touch is detected, the fingerprint touch display integrated circuit 502 can initiate a dark screen fingerprint sensing operation, and at the same time, the fingerprint touch display integrated circuit 502 can send an interrupt signal to wake up the fingerprint part 514 of the system processor 500. Then, the fingerprint part 514 can start fingerprint recognition after the fingerprint sensing is completed and the fingerprint image data from the fingerprint touch display integrated circuit 502 is received. Subsequently, the fingerprint touch display integrated circuit 502 can execute a sleep program to enter the sleep mode, and then execute a display recovery program when receiving the fingerprint recognition result from the system processor 500. Accordingly, the system processor 500 can wake up the display part 512 to enable normal display operation. In normal display operation, the system processor 500 can send a video stream through the mobile industry processor interface between the display part 512 of the system processor 500 and the display control circuit 524 of the fingerprint touch display integrated circuit 502.

[0104] In order to perform a handshake between the system processor 500 and the fingerprint touch display integrated circuit 502, a status signal port can be set between the two. In detail, when the fingerprint touch display integrated circuit 502 is activated to perform dark screen fingerprint sensing or start normal display, the status signal port can be pulled to a specific state (such as a high voltage); when the dark screen fingerprint sensing process is completed and the display control circuit 524 and the fingerprint control circuit 526 enter the sleep mode, the status signal port can be pulled to another state (such as a low voltage). Before the system processor 500 wants to control the fingerprint touch display integrated circuit 502 to start the display recovery program to perform normal display operations, the system processor 500 needs to determine whether the status signal port is in a low voltage state to ensure that the fingerprint touch display integrated circuit 502 operates normally and safely.

[0105] The above-mentioned operation mode of dark screen fingerprint unlocking can be summarized as a dark screen fingerprint unlocking process 200 of an embodiment of the present invention, such as Fig. 20 The dark screen fingerprint unlocking process 200 can be implemented in a display system (such as Figure 5 The display system 50) comprises the following steps:

[0106] Step 2002: The touch control circuit 522 executes a low-power wake-up gesture operation.

[0107] Step 2004: The touch control circuit 522 determines whether there is a finger touch on the display screen 504. If yes, step 2010 is executed for the operation of the fingerprint touch display integrated circuit 502 and step 2020 is executed for the operation of the system processor 500; if no, step 2002 is executed.

[0108] Step 2010 : The touch control circuit 522 wakes up the display control circuit 524 and the fingerprint control circuit 526 .

[0109] Step 2012: The fingerprint control circuit 526 performs fingerprint sensing, and the display control circuit 524 displays the light spot through the internal clock.

[0110] Step 2014 : The fingerprint control circuit 526 sends the fingerprint image data to the system processor 500 .

[0111] Step 2016: The display control circuit 524 and the fingerprint control circuit 526 enter the sleep mode.

[0112] Step 2020: The fingerprint portion 514 of the system processor 500 is awakened.

[0113] Step 2022: The fingerprint portion 514 receives fingerprint image data.

[0114] Step 2024: The fingerprint part 514 performs fingerprint recognition.

[0115] Step 2026: The display portion 512 of the system processor 500 is awakened to control the display screen 504 to display the fingerprint recognition result.

[0116] In another embodiment, the fingerprint control circuit 526 in the fingerprint touch display integrated circuit 502 can start to perform fingerprint sensing under the permission of the system processor 500 to improve the security of the display system 50. In this case, the dark screen fingerprint unlocking process can be modified as follows Fig.21 According to one embodiment of the present invention, Fig.21 Another dark screen fingerprint unlocking process 210 is shown, which includes the following steps:

[0117] Step 2102: The touch control circuit 522 performs a low power consumption wake-up gesture operation.

[0118] Step 2104: The touch control circuit 522 determines whether there is a finger touch on the display screen 504. If yes, step 2110 is executed for the operation of the fingerprint touch display integrated circuit 502 and step 2120 is executed for the operation of the system processor 500; if no, step 2102 is executed.

[0119] Step 2110 : The touch control circuit 522 wakes up the display control circuit 524 and the fingerprint control circuit 526 .

[0120] Step 2111 : The fingerprint control circuit 526 receives permission for fingerprint sensing from the system processor 500 .

[0121] Step 2112: The fingerprint control circuit 526 performs fingerprint sensing, and the display control circuit 524 displays the light spot through the internal clock.

[0122] Step 2114 : The fingerprint control circuit 526 sends the fingerprint image data to the system processor 500 .

[0123] Step 2116: The display control circuit 524 and the fingerprint control circuit 526 enter the sleep mode.

[0124] Step 2120: The fingerprint portion 514 of the system processor 500 is awakened.

[0125] Step 2121: The fingerprint section 514 decides to enable fingerprint sensing.

[0126] Step 2122: The fingerprint portion 514 receives fingerprint image data.

[0127] Step 2124: The fingerprint part 514 performs fingerprint recognition.

[0128] Step 2126: The display portion 512 of the system processor 500 is awakened to control the display screen 504 to display the fingerprint recognition result.

[0129] For the detailed operation and changes of the dark screen fingerprint unlocking processes 200 and 210, please refer to the description in the above paragraphs and will not be repeated here.

[0130] In another embodiment, the touch control circuit 522 can determine the validity of the finger touch according to the touch sensing area, the touch signal strength and / or the predetermined touch gesture. In this case, the dark screen fingerprint unlocking process can be modified as follows: Fig. 22 According to one embodiment of the present invention, Fig. 22 Another dark screen fingerprint unlocking process 220 is shown, which includes the following steps:

[0131] Step 2202: The touch control circuit 522 performs a low power consumption wake-up gesture operation.

[0132] Step 2204: The touch control circuit 522 determines whether there is a finger touching the display screen 504. If yes, execute step 2206; if no, execute step 2202.

[0133] Step 2206: The touch control circuit 522 determines whether the finger touch is valid. If yes, step 2210 is executed for the operation of the fingerprint touch display integrated circuit 502 and step 2220 is executed for the operation of the system processor 500; if no, step 2202 is executed.

[0134] Step 2210 : The touch control circuit 522 wakes up the display control circuit 524 and the fingerprint control circuit 526 .

[0135] Step 2212: The fingerprint control circuit 526 performs fingerprint sensing, and the display control circuit 524 displays the light spot through the internal clock.

[0136] Step 2214 : The fingerprint control circuit 526 sends the fingerprint image data to the system processor 500 .

[0137] Step 2216: The display control circuit 524 and the fingerprint control circuit 526 enter the sleep mode.

[0138] Step 2220: The fingerprint portion 514 of the system processor 500 is awakened.

[0139] Step 2222: The fingerprint portion 514 receives fingerprint image data.

[0140] Step 2224: The fingerprint part 514 performs fingerprint recognition.

[0141] Step 2226: The display portion 512 of the system processor 500 is awakened to control the display screen 504 to display the fingerprint recognition result.

[0142] In the above embodiment, the fingerprint part 514 of the system processor 500 is awakened when the fingerprint control circuit 526 starts to perform fingerprint sensing. In an alternative embodiment, the display part 512 and the fingerprint part 514 of the system processor 500 can be awakened after the fingerprint sensing is completed and the fingerprint touch display integration circuit 502 is ready to send fingerprint image data to the system processor 500. In this case, the dark screen fingerprint unlocking process can be modified as follows Fig.23 According to one embodiment of the present invention, Fig.23 Another dark screen fingerprint unlocking process 230 is shown, which includes the following steps:

[0143] Step 2302: The touch control circuit 522 performs a low power consumption wake-up gesture operation.

[0144] Step 2304: The touch control circuit 522 determines whether there is a finger touching the display screen 504. If yes, execute step 2310; if no, execute step 2302.

[0145] Step 2310 : The touch control circuit 522 wakes up the display control circuit 524 and the fingerprint control circuit 526 .

[0146] Step 2312: The fingerprint control circuit 526 ends fingerprint sensing.

[0147] Step 2314 : The fingerprint control circuit 526 sends the fingerprint image data to the system processor 500 .

[0148] Step 2316: The display control circuit 524 and the fingerprint control circuit 526 enter the sleep mode.

[0149] Step 2320: The fingerprint portion 514 of the system processor 500 is awakened.

[0150] Step 2322: The fingerprint portion 514 receives fingerprint image data.

[0151] Step 2324: The fingerprint part 514 performs fingerprint recognition.

[0152] Step 2326: The display portion 512 of the system processor 500 is awakened to control the display screen 504 to display the fingerprint recognition result.

[0153] For the detailed operation and changes of the dark screen fingerprint unlocking processes 220 and 230, please refer to the description in the above paragraphs and will not be repeated here.

[0154] It is worth noting that in other alternative embodiments, when performing the steps of detecting finger touch, displaying at least one light spot, fingerprint sensing, and sending fingerprint image data to the system processor, the display part of the system processor does not need to be continuously maintained in sleep mode. In some embodiments, at least the step of displaying at least one light spot can be performed without the intervention of the display part of the system processor, and the display part can be in sleep mode to achieve the purpose of power saving. In another embodiment, at least one of detecting finger touch and displaying at least one light spot can be performed when the display part of the system processor is maintained in sleep state, which means that not all of the above four steps need to be performed when the display part of the system processor is maintained in sleep state. In some embodiments, at least one of detecting finger touch and displaying at least one light spot can be performed when the area on the display screen (i.e., screen) other than the display light spot is maintained in dark screen. Therefore, the control circuit can be used to be responsible for the display of the light spot without the intervention of the display part of the system processor, which means that various methods that can be used to save power or reduce the intervention of the system processor and / or display screen belong to the application of the present invention.

[0155] In summary, an embodiment of the present invention provides a control circuit (such as a fingerprint touch display integrated circuit) that can be used to perform a dark screen fingerprint unlocking function to unlock the display screen according to fingerprint recognition. During the dark screen fingerprint unlocking process, the display part of the system processor can be maintained in a sleep state. The control circuit can perform dark screen fingerprint sensing, wherein the display control circuit can control the display screen to display a light spot through an internal clock of the control circuit without the intervention of the system processor. And the fingerprint control circuit can use the light spot displayed by the display control circuit of the fingerprint touch display integrated circuit to perform optical fingerprint sensing. The touch control circuit can be used to perform low-power wake-up gesture operations to determine whether there is a valid finger touch on the display screen, and accordingly provide relevant information (such as position information) of the finger touch to the display control circuit and the fingerprint control circuit. In different embodiments, the control circuit can wake up the fingerprint part of the system processor before the fingerprint sensing process starts or after the fingerprint sensing process is completed. In different embodiments, the fingerprint control circuit can start to perform fingerprint sensing operations with the permission of the system processor, or perform fingerprint sensing operations without the permission of the system processor. Then, when the fingerprint sensing is completed, the control circuit can output the fingerprint image data to the system processor, and the fingerprint part of the system processor can perform fingerprint recognition on the received fingerprint image data. In addition, the system processor can also control the control circuit to execute a display recovery program to start normal display operation, in which the image data is received from the system processor. In different embodiments, the display recovery program can be started at any desired time point, or even the display recovery program can be removed. When the recognition fails, the screen can be lit up and the recognition result can be displayed through the normal display function, thereby executing the bright screen fingerprint unlocking process; or, when the recognition fails, the screen can be maintained in a dark screen state, thereby executing the dark screen fingerprint unlocking process. The display screen can be further used to display the fingerprint recognition results. The dark screen fingerprint unlocking process can shorten the time required for fingerprint sensing and recognition, and the finger does not need to be removed from the screen during fingerprint sensing. In this way, the user experience of fingerprint recognition can be effectively improved.

[0156] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0157] The words "one" and "an" and "the" and "at least one" and similar indicative words used in the text of this specification (especially the text of the claims) should be interpreted as covering the singular and the plural, unless otherwise indicated herein or the context is clearly contradictory. The wording "at least one" used to connect one or more items in a column (such as at least one of A and B) should be interpreted as selecting one item (A or B) from the listed items or any combination of two or more items in the listed items (A and B), unless otherwise indicated herein or the context is clearly contradictory. The words "comprising", "having", "including" and "comprising" should be interpreted as open terms (i.e., meaning "including but not limited to"), unless otherwise noted. The numerical ranges recorded herein are intended only to be used as a shortcut method for individually citing individual numerical values ​​falling within the range, and each individual numerical value is included in the specification, as listed in this article.

[0158] All methods described herein can be performed in any suitable order, unless otherwise indicated herein or the context is clearly contradictory. Any and all embodiments or exemplary language (such as "for example") used herein are only for better explanation of the present invention and do not limit the scope of the present invention unless otherwise stated. Any language in the specification should not be interpreted as indicating any non-requested protection element that is critical to the implementation of the present invention.

[0159] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A control circuit coupled to a system processor and a display screen, the control circuit comprising: a touch control circuit, used for detecting a finger touch on the display screen to generate finger touch position information; a display control circuit, used for controlling the display screen to display at least one light spot according to the finger touch position information transmitted to the display control circuit by the touch control circuit, wherein the position of the light spot is determined according to the finger touch position information; and A fingerprint control circuit is used to perform fingerprint sensing through at least one fingerprint sensor corresponding to the position touched by the finger according to the finger touch position information transmitted to the fingerprint control circuit by the touch control circuit, and send fingerprint image data to the system processor, wherein the fingerprint image data corresponds to the sensing signal received from the at least one fingerprint sensor; wherein each of the above steps is performed by the control circuit when a display part of the system processor is maintained in a sleep state.

2. The control circuit according to claim 1, characterized in that: The fingerprint control circuit is also used for providing an interrupt signal before the fingerprint sensing is finished to wake up a fingerprint part of the system processor.

3. The control circuit according to claim 2, characterized in that: The fingerprint control circuit is also used for providing the interrupt signal before the fingerprint sensing starts to wake up the fingerprint part of the system processor.

4. The control circuit according to claim 1, characterized in that: The fingerprint control circuit is also used for providing an interrupt signal after the fingerprint sensing is completed to wake up a fingerprint part of the system processor.

5. The control circuit according to claim 1, characterized in that: The fingerprint control circuit is awakened or notified by the touch control circuit and starts to perform the fingerprint sensing through the at least one fingerprint sensor under the permission of the system processor.

6. The control circuit according to claim 1, characterized in that: The fingerprint control circuit is awakened or notified by the touch control circuit to start performing the fingerprint sensing through the at least one fingerprint sensor without permission from the system processor.

7. The control circuit according to claim 1, characterized in that: In the sleep state, the control circuit does not receive image information related to the at least one light spot from the system processor.

8. The control circuit according to claim 7, characterized in that: The image information related to the at least one light spot includes position information of the at least one light spot.

9. The control circuit according to claim 1, characterized in that: The display control circuit is used for controlling a backlight source and / or a brightness of the display screen to display the at least one light spot without receiving the instruction of the display part of the system processor.

10. The control circuit according to claim 1, characterized in that: When the touch control circuit determines that the finger touch is valid, the touch control circuit is used to wake up or notify the display control circuit to display the at least one light spot.

11. The control circuit according to claim 10, characterized in that: The touch control circuit determines whether the finger touch is valid according to at least one of a touch sensing area, a touch signal strength and a predetermined touch gesture.

12. The control circuit according to claim 1, characterized in that: The touch control circuit is used to detect the finger touch under a low power consumption wake-up gesture operation.

13. The control circuit according to claim 1, characterized in that: The touch control circuit is used in a first touch detection mode to detect whether there is a touch on the display screen, and after detecting the presence of a touch on the display screen, it is used in a second touch detection mode to determine the position of the finger touch, wherein the second touch detection mode consumes more power than the first touch detection mode.

14. The control circuit according to claim 1, characterized in that: When the fingerprint recognition of the system processor indicates a failure result, the display part of the system processor is maintained in the sleep state, so that the display control circuit is not used to drive the display screen to display the failure result, and the touch control circuit is used to restart detecting a finger touch on the display screen.

15. The control circuit according to claim 14, characterized in that: The touch control circuit restarts the detection by detecting whether there is a touch on the display screen.

16. The control circuit according to claim 15, characterized in that: The touch control circuit restarts the detection by detecting a touch position of the touch on the display screen.

17. The control circuit according to claim 1, characterized in that: After the system processor completes the fingerprint identification based on the fingerprint image data, the display part of the system processor is changed to a wake-up state, so that the display control circuit is used to drive the display screen to display a fingerprint identification result.

18. The control circuit according to claim 17, characterized in that: When the fingerprint identification indicates a failure result, the fingerprint control circuit restarts fingerprint sensing when the display portion of the system processor is in the awake state.

19. The control circuit according to claim 17, characterized in that: When the display portion of the system processor is transferred to the awake state, a display recovery procedure is executed.

20. The control circuit according to claim 19, characterized in that: After the display control circuit receives the fingerprint identification result from the system processor, the control circuit starts to execute the display recovery program.

21. The control circuit according to claim 19, characterized in that: Before the display control circuit receives the fingerprint identification result from the system processor, the control circuit starts to execute the display recovery program.

22. The control circuit according to claim 21, characterized in that The display recovery program is executed and completed at the same time when the control circuit receives the fingerprint recognition result.

23. The control circuit according to claim 17, characterized in that: After the fingerprint control circuit completes the step of executing fingerprint sensing, the display control circuit is used to drive the display screen to display the fingerprint recognition result without executing a display recovery program.

24. The control circuit according to claim 1, characterized in that: In the step of performing fingerprint sensing, the touch control circuit is used to determine whether the finger touch remains on the display screen.

25. The control circuit according to claim 24, characterized in that: When the touch control circuit detects that the finger touches and leaves the display screen, the fingerprint control circuit is used to stop executing the fingerprint sensing.

26. A method for controlling a display screen, for a control circuit, the control circuit being coupled to a system processor, the method comprising: A touch control circuit of the control circuit detects a finger touch on the display screen to generate finger touch position information; A display control circuit of the control circuit controls the display screen to display at least one light spot according to the finger touch position information transmitted to the display control circuit by the touch control circuit, wherein the position of the light spot is determined according to the finger touch position information; A fingerprint control circuit of the control circuit performs fingerprint sensing through at least one fingerprint sensor corresponding to the position touched by the finger according to the finger touch position information transmitted to the fingerprint control circuit by the touch control circuit; and The fingerprint control circuit sends fingerprint image data to the system processor, wherein the fingerprint image data corresponds to the sensing signal received from the at least one fingerprint sensor; Each of the above steps is executed by the control circuit when a display part of the system processor is maintained in a sleep state.

27. The method of claim 26, wherein: Also includes: The fingerprint control circuit provides an interrupt signal to wake up a fingerprint part of the system processor before the fingerprint sensing ends.

28. The method of claim 27, wherein: The step of providing the interrupt signal by the fingerprint control circuit to wake up the fingerprint part of the system processor before the fingerprint sensing ends includes: The fingerprint control circuit provides the interrupt signal to wake up the fingerprint part of the system processor before the fingerprint sensing starts.

29. The method of claim 26, wherein: Also includes: The fingerprint control circuit provides an interrupt signal to wake up a fingerprint part of the system processor after the fingerprint sensing is completed.

30. The method of claim 26, wherein: Also includes: The touch control circuit wakes up or notifies the fingerprint control circuit, wherein the fingerprint control circuit starts to perform the fingerprint sensing through the at least one fingerprint sensor under the permission of the system processor.

31. The method of claim 26, wherein: Also includes: The touch control circuit wakes up or notifies the fingerprint control circuit, wherein the fingerprint control circuit starts to perform the fingerprint sensing through the at least one fingerprint sensor without permission from the system processor.

32. The method of claim 26, wherein: Also includes: In the sleep state, the control circuit does not receive image information related to the at least one light spot from the system processor.

33. The method of claim 32, wherein: The image information related to the at least one light spot includes position information of the at least one light spot.

34. The method of claim 26, wherein: Also includes: The display control circuit controls a backlight source and / or a brightness of the display screen to display the at least one light spot without receiving an instruction from the display part of the system processor.

35. The method of claim 26, wherein: Also includes: When the touch control circuit determines that the finger touch is valid, the touch control circuit wakes up or notifies the display control circuit to display the at least one light spot.

36. The method of claim 35, wherein: The step of the touch control circuit detecting the finger touch on the display screen comprises: The touch control circuit determines whether the finger touch is valid according to at least one of a touch sensing area, a touch signal strength and a predetermined touch gesture.

37. The method of claim 26, wherein: The step of the touch control circuit detecting the finger touch on the display screen comprises: The touch control circuit detects the finger touch under a low power consumption wake-up gesture operation.

38. The method of claim 26, wherein: The step of the touch control circuit detecting the finger touch on the display screen comprises: The touch control circuit detects whether there is a touch on the display screen in a first touch detection mode; and After detecting a touch on the display screen, the touch control circuit determines the position of the finger touch in a second touch detection mode; The second touch detection mode consumes more power than the first touch detection mode.

39. The method of claim 26, wherein: When the fingerprint recognition of the system processor indicates a failure result, the display part of the system processor is maintained in the sleep state, so that the display control circuit is not used to drive the display screen to display the failure result, and the method also includes: the touch control circuit restarts to detect a finger touch on the display screen.

40. The method of claim 39, wherein: The step of the touch control circuit restarting to detect the finger touch on the display screen comprises: The touch control circuit restarts the detection by detecting whether there is a touch on the display screen.

41. The method of claim 40, wherein: The step of the touch control circuit restarting to detect the finger touch on the display screen also includes: The touch control circuit restarts the detection by detecting a touch position of the touch on the display screen.

42. The method of claim 26, wherein: After the system processor completes the fingerprint identification based on the fingerprint image data, the display part of the system processor is changed to a wake-up state, so that the display control circuit is used to drive the display screen to display a fingerprint identification result.

43. The method of claim 42, wherein: Also includes: When the fingerprint identification indicates a failure result, the fingerprint control circuit restarts fingerprint sensing when the display portion of the system processor is in the awake state.

44. The method of claim 42, wherein: When the display portion of the system processor is transferred to the awake state, a display recovery procedure is executed.

45. The method of claim 44, wherein: Also includes: After the display control circuit receives the fingerprint identification result from the system processor, the control circuit starts to execute the display recovery program.

46. ​​The method of claim 44, wherein: Also includes: Before the display control circuit receives the fingerprint identification result from the system processor, the control circuit starts to execute the display recovery program.

47. The method of claim 46, wherein: The display recovery program is executed and completed at the same time when the control circuit receives the fingerprint recognition result.

48. The method of claim 42, wherein: Also includes: After the fingerprint control circuit completes the step of performing fingerprint sensing, the display control circuit drives the display screen to display the fingerprint recognition result without performing a display recovery procedure.

49. The method of claim 26, wherein: Also includes: In the step of performing fingerprint sensing, the touch control circuit determines whether the finger touch remains on the display screen.

50. The method of claim 49, wherein: Also includes: When the touch control circuit detects that the finger touches and leaves the display screen, the fingerprint control circuit stops executing the fingerprint sensing.

51. A display system comprising: A display screen; A system processor; as well as A control circuit coupled to the system processor and used to control the display screen, the control circuit comprising: a touch control circuit, used for detecting a finger touch on the display screen to generate finger touch position information; a display control circuit, used for controlling the display screen to display at least one light spot according to the finger touch position information transmitted to the display control circuit by the touch control circuit, wherein the position of the light spot is determined according to the finger touch position information; and a fingerprint control circuit, configured to perform fingerprint sensing through at least one fingerprint sensor corresponding to the position touched by the finger according to the finger touch position information transmitted to the fingerprint control circuit by the touch control circuit, and send fingerprint image data to the system processor, wherein the fingerprint image data corresponds to the sensing signal received from the at least one fingerprint sensor; Each of the above steps is executed by the control circuit when a display part of the system processor is maintained in a sleep state.

52. The display system of claim 51, wherein: The fingerprint control circuit is also used for providing an interrupt signal before the fingerprint sensing is finished to wake up a fingerprint part of the system processor.

53. The display system of claim 52, wherein: The fingerprint control circuit is also used for providing the interrupt signal before the fingerprint sensing starts to wake up the fingerprint part of the system processor.

54. The display system of claim 51, wherein: The fingerprint control circuit is also used for providing an interrupt signal after the fingerprint sensing is completed to wake up a fingerprint part of the system processor.

55. The display system of claim 51, wherein: The fingerprint control circuit is awakened or notified by the touch control circuit and starts to perform the fingerprint sensing through the at least one fingerprint sensor under the permission of the system processor.

56. The display system of claim 51, wherein: The fingerprint control circuit is awakened or notified by the touch control circuit to start performing the fingerprint sensing through the at least one fingerprint sensor without permission from the system processor.

57. The display system of claim 51, wherein: In the sleep state, the control circuit does not receive image information related to the at least one light spot from the system processor.

58. The display system of claim 57, wherein: The image information related to the at least one light spot includes position information of the at least one light spot.

59. The display system of claim 51, wherein: The display control circuit is used for controlling a backlight source and / or a brightness of the display screen to display the at least one light spot without receiving the instruction of the display part of the system processor.

60. The display system of claim 51, wherein: When the touch control circuit determines that the finger touch is valid, the touch control circuit is used to wake up or notify the display control circuit to display the at least one light spot.

61. The display system of claim 60, wherein: The touch control circuit determines whether the finger touch is valid according to at least one of a touch sensing area, a touch signal strength and a predetermined touch gesture.

62. The display system of claim 51, wherein: The touch control circuit is used to detect the finger touch under a low power consumption wake-up gesture operation.

63. The display system of claim 51, wherein: The touch control circuit is used in a first touch detection mode to detect whether there is a touch on the display screen, and after detecting the presence of a touch on the display screen, it is used in a second touch detection mode to determine the position of the finger touch, wherein the second touch detection mode consumes more power than the first touch detection mode.

64. The display system of claim 51, wherein: When the fingerprint recognition of the system processor indicates a failure result, the display part of the system processor is maintained in the sleep state, so that the display control circuit is not used to drive the display screen to display the failure result, and the touch control circuit is used to restart detecting a finger touch on the display screen.

65. The display system of claim 64, wherein: The touch control circuit restarts the detection by detecting whether there is a touch on the display screen.

66. The display system of claim 65, wherein: The touch control circuit restarts the detection by detecting a touch position of the touch on the display screen.

67. The display system of claim 51, wherein: After the system processor completes the fingerprint identification based on the fingerprint image data, the display part of the system processor is changed to a wake-up state, so that the display control circuit is used to drive the display screen to display a fingerprint identification result.

68. The display system of claim 67, wherein: When the fingerprint identification indicates a failure result, the fingerprint control circuit restarts fingerprint sensing when the display portion of the system processor is in the awake state.

69. The display system of claim 67, wherein: When the display portion of the system processor is transferred to the awake state, a display recovery procedure is executed.

70. The display system of claim 69, wherein: After the display control circuit receives the fingerprint identification result from the system processor, the control circuit starts to execute the display recovery program.

71. The display system of claim 69, wherein: Before the display control circuit receives the fingerprint identification result from the system processor, the control circuit starts to execute the display recovery program.

72. The display system of claim 71, wherein: The display recovery program is executed and completed at the same time when the control circuit receives the fingerprint recognition result.

73. The display system of claim 67, wherein: After the fingerprint control circuit completes the step of executing fingerprint sensing, the display control circuit is used to drive the display screen to display the fingerprint recognition result without executing a display recovery program.

74. The display system of claim 51, wherein: In the step of performing fingerprint sensing, the touch control circuit is used to determine whether the finger touch remains on the display screen.

75. The display system of claim 74, wherein: When the touch control circuit detects that the finger touches and leaves the display screen, the fingerprint control circuit is used to stop executing the fingerprint sensing.

76. A control circuit coupled to a system processor and a display screen, the control circuit comprising: a touch control circuit, used for detecting a finger touch on the display screen to generate finger touch position information; a display control circuit, for controlling the display screen to display at least one light spot according to the finger touch position information transmitted to the display control circuit by the touch control circuit without the intervention of a display portion of the system processor, wherein the position of the light spot is determined according to the finger touch position information; and A fingerprint control circuit is used to perform fingerprint sensing through at least one fingerprint sensor corresponding to the position touched by the finger according to the finger touch position information transmitted to the fingerprint control circuit by the touch control circuit, and send fingerprint image data to the system processor, wherein the fingerprint image data corresponds to the sensing signal received from the at least one fingerprint sensor.

77. The control circuit of claim 76, wherein: When the display part of the system processor is in a sleep state, the touch control circuit is used to detect the finger touch, and the display control circuit is used to control the display screen to display the at least one light spot.

78. The control circuit of claim 76, wherein: When the area on the display screen other than the area displaying the at least one light spot is continuously kept dark, the touch control circuit is used to detect the finger touch, and the display control circuit is used to control the display screen to display the at least one light spot.

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