Patent Publication Number: US-2019180664-A1

Title: Display device and privacy protecting method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 106142917, filed on Dec. 7, 2017. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a display device, and particularly relates to a display device capable of adjusting a viewing angle of a part of a display image and a privacy protecting method thereof. 
     Description of Related Art 
     Generally, a screen of a display device generally has a wide viewing angle display effect, though in some cases, for example, in case that personal data or other classified data is processed in public places, the wide viewing angle display effect is easy to make the processed data to be peeped by others to cause private data leakage. A conventional privacy protecting method is to add a privacy protecting film on the screen of the display device to achieve a function of reducing the viewing angle of the full display image. However, besides that the privacy protecting film is easy to influence display quality, viewing angle adjustment of a part of the display image cannot be implemented. 
     Therefore, it is necessary to provide a display device and a privacy protecting method thereof to dynamically adjust a viewing angle of a part of the display image according to a usage requirement. 
     SUMMARY OF THE INVENTION 
     The invention is directed to a display device and a privacy protecting method thereof, which are adapted to dynamically adjust a viewing angle of a part of a display image according to a privacy information region in the display image. 
     An embodiment of the invention provides a privacy protecting method. The privacy protecting method includes: analyzing a display image on a display panel so as to determine at least one privacy information region in the display image; configuring at least one privacy protecting region on a privacy protecting mask according to at least one of a first area and a first position of the at least one privacy information region, so that a viewing angle of the privacy information region is limited by the privacy protecting region of the privacy protecting mask, and a viewing angle of other region in the display image is not limited; detecting whether at least one of the first area and the first position is changed; and changing at least one of a second area and a second position of the privacy protecting region of the privacy protecting mask in case that at least one of the first area and the first position of the privacy information region is changed. 
     An embodiment of the invention provides a display device including a display panel, a display image analyzing module, a privacy protecting mask and a control module. The display panel is configured to display a display image. The display image analyzing module is configured to analyze the display image to determine at least one privacy information region in the display image. The privacy protecting mask is disposed on the display panel. The control module is coupled to the display panel, the display image analyzing module and the privacy protecting mask. The control module configures at least one privacy protecting region on the privacy protecting mask according to at least one of a first area and a first position of the at least one privacy information region, so that a viewing angle of the privacy information region is limited by the privacy protecting region of the privacy protecting mask, and a viewing angle of other region in the display image is not limited. The control module detects whether at least one of the first area and the first position is changed. If it is detected that at least one of the first area and the first position of the privacy information region is changed, the control module accordingly changes at least one of a second area and a second position of the privacy protecting region of the privacy protecting mask. 
     An embodiment of the invention provides a privacy protecting method. The privacy protecting method includes: detecting a position of a display device; and determining whether to activate a privacy protecting mask to limit a viewing angle of at least one privacy information region in a display image of a display panel according to the position of the display device. 
     An embodiment of the invention provides a display device including a display panel, a privacy protecting mask, a position detecting circuit and a control module. The display panel is configured to display a display image. The privacy protecting mask is disposed on the display panel. The position detecting circuit is configured to detect a position of the display device. The control module is coupled to the display panel, the privacy protecting mask and the position detecting circuit. The control module determines whether to activate the privacy protecting mask to limit a viewing angle of at least one privacy information region in the display image of the display panel according to the position of the display device. 
     According to the above description, the display device and the privacy protecting method thereof are adapted to automatically detect whether an application executed by a user has privacy information, so as to adjust a viewing angle of a part of region of the display image to implement privacy protection. 
     In order to make the aforementioned and other features and advantages of the invention comprehensible, several exemplary embodiments accompanied with figures are described in detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  is a circuit block schematic diagram of a display device according to an embodiment of the invention. 
         FIG. 2  is a schematic diagram of a driving structure of a display panel according to an embodiment of the invention. 
         FIG. 3  is a schematic diagram of adjusting a viewing angle according to an embodiment of the invention. 
         FIGS. 4A-4E  are flowcharts illustrating privacy protecting methods according to different embodiments of the invention. 
         FIGS. 5A-5C  are schematic diagrams of shift and change of a privacy information region according to an embodiment of the invention. 
         FIG. 6  is a flowchart illustrating a privacy protecting method according to another embodiment of the invention. 
         FIGS. 7A-7B  are schematic diagrams of adjusting a viewing angle according to another embodiment of the invention. 
         FIG. 8  is a schematic diagram of a privacy protecting strategy of a mask database according to an embodiment of the invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Wherever possible, components/members/steps using the same referential numbers in the drawings and description refer to the same or like parts. Components/members/steps using the same referential numbers or using the same terms in different embodiments may cross-refer related descriptions. 
       FIG. 1  is a circuit block schematic diagram of a display device according to an embodiment of the invention. The display device  1  includes a position detecting circuit  11 , a display image analyzing module  12 , a control module  13 , a privacy protecting mask  14  and a display panel  15 . The display panel  15  may present a display image. The display image analyzing module  12  may analyze the display image to determine a position in the display image required to configure a privacy information region. The position detecting circuit  11  may detect a position of the display device  1 . The control module  13  is coupled to the position detecting circuit  11 , the display image analyzing module  12 , the privacy protecting module  14  and the display panel  15 . The privacy protecting module  14  is disposed on the display panel  15 . By controlling a privacy protecting region configured on the privacy protecting mask  14 , viewing angle adjustment is performed to a partial region of the display image, for example, to limit a viewing angle of the privacy information region without limiting a viewing angle of other region in the display image, so as to protect privacy. 
     The position detecting circuit  11  includes a positioning circuit  111 , a height detecting circuit  112  and an image sensing circuit  113 . The positioning circuit  111 , for example, detects a horizontal position (latitude and longitude) of the display device  1  through a global positioning system (GPS) device. The height detecting circuit  112 , for example, detects a height (the height of a floor where the display device  1  is located) of the display device  1  through a height detector. The image sensing circuit  113 , for example, captures an environment image of the display device  1  through a camera lens of the display device  1 , and the control module  13  captures at least one position feature from the environment image to determine the position of the display device. Therefore, the position detecting circuit  11  may be used for determining whether the display device  1  is in a private place or a public place. 
       FIG. 2  is a schematic diagram of a driving structure of a display panel according to an embodiment of the invention. Referring to  FIG. 1  and  FIG. 2 , the privacy protecting mask  14  of the present embodiment is a polymer dispersed liquid crystal (PDLC) film integrated with the display panel  15 . The PDLC film  141  is electrically connected to a control chip  131 , and is connected to a motherboard  132  of the display device  1  through an inter-integrated circuit (I 2 C) interface. The control chip  131  may be configured with a microcontroller unit (MCU) for controlling the PDLC film  141 , and transforms a region on the display panel  15  that has to be masked into a region on the PDLC film  141 . 
     For example, the region on the display panel  15  to be masked corresponds to a region on the PDLC film  141  in a proportional manner, and channels on the PDLC film  141  to be activated are selected through a voltage value applied to the PDLC film  141 . For example, if a resolution of the display panel  15  is Rx*Ry, the region to be masked is (X1,Y1) to (X2,Y2), and the number of channels of the PDLC  141  is CHx*CHy, the number of the channels of the PDLC film  141  to be activated may be represented by a following expression: 
         X  axis: from ( CHx*X 1)/ Rx  to ( CHx*X 2)/ Rx;    
         Y  axis: from ( CHy*X 1)/ Ry  to ( CHy*X 2)/ Ry.    
     Therefore, a proper number of channels of the PDLC film  141  may be activated according to the above method, and packet control is transceived through the I2C interface in order to mask an appointed region in the display image. 
       FIG. 4A  is a flowchart illustrating a privacy protecting method according to an embodiment of the invention. Referring to  FIG. 1  and  FIG. 4 , in step S 30 , the display image analyzing module  12  analyzes a display image on the display panel  15  to determine a configuration position of a privacy information region. A following table  1  lists analyzing information of the display image analyzing module  12  according to an embodiment of the invention. As shown in the table  1 , the display image probably has windows of a plurality of applications AP 1 -AP 8 . The display image analyzing module  12  may detect the application executed by the display device  1 , and transmit related analyzing data such as a name of the application, whether confidential information is contained and a location (represented by an X coordinate and a Y coordinate) of the confidential information, etc. to the control module  13 , so as to determine and area and a position of the privacy information region in the display image. The display image analyzing module  12  may further detect whether the application executed by the display device  1  contains a specific privacy information feature to obtain a detection result. According to a design requirement, the privacy information feature may include “password”, “confidential”, “secret”, “code number”, “account number”, “log in”, “sign in”, “register”, “birthday”, “name”, “ID number” (or “identification number”), “verification code” or other keywords (or text image) appeared in the display image, or a dynamic keyboard, a software keyboard or other image/object appeared in the display image. The display image analyzing module  12  may transmit the detection result to the control module  13  to determine whether an application including specific privacy information is activated. 
     
       
         
           
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Confidential information 
                 Location of confidential 
               
               
                 Name of application 
                 contained? 
                 region 
               
               
                   
               
             
            
               
                 AP1 
                 No 
                 None 
               
               
                 AP2 
                 No 
                 None 
               
               
                 AP3 
                 Yes 
                 AP3 (X1, Y1, X2, Y2) 
               
               
                 AP4 
                 No 
                 None 
               
               
                 AP5 
                 Yes 
                 AP5 (X1, Y1, X2, Y2) 
               
               
                 AP6 
                 Yes 
                 AP6 (X1, Y1, X2, Y2) 
               
               
                 AP7 
                 Yes 
                 AP7 (X1, Y1, X2, Y2) 
               
               
                 AP8 
                 No 
                 None 
               
               
                   
               
            
           
         
       
     
     After the area and the position of the privacy information region in the display image are determined, the control module  13  configures the required number of privacy protecting regions on the privacy protecting mask  14  (step S 301 ). The privacy protecting region of the privacy protecting mask  14  may limit a viewing angle of the privacy information region of the display panel  15 . For example, the viewing angle of the privacy information region may be adjusted through a voltage value applied to the privacy protecting mask  14 , as shown in  FIG. 3 , different applied voltage may influence a haze value of the privacy protecting mask  14 , for example, when a saturation voltage is 20V, the privacy protecting mask  14  is completely transparent, and the viewing angle reaches the minimum value; when the saturation voltage is 10V, the privacy protecting mask  14  is semi-hazed, and the viewing angle is expanded; and when none voltage is applied to the privacy protecting mask  14 , a wide viewing angle display effect is achieved. 
     Then, the display image analyzing module  12  continually detects whether the area or the position of the privacy information region is changed (step S 40 ), for example, whether a window containing the privacy information is shifted or enlarged/diminished. If it is detected that the area or the position of the privacy information region is changed, a step S 50  is executed, by which the control module  13  accordingly changes an area and a position of the privacy protecting region, for example, resets the area or the position of the privacy protecting region according to the shift and the size change of the window containing the privacy information, so as to correspondingly set a new privacy information region in the display image. 
       FIGS. 5A-5C  are schematic diagrams of shift and change of the privacy information region according to an embodiment of the invention. If the window containing the privacy information is shifted or a size thereof is changed, the executed application may notify the control module  13  through an application programming interface of the display device  1 , so as to synchronously change a mask range. For example, as shown in  FIG. 5A , the display image of the display panel  15  is divided into a privacy information region  151  and a non-privacy information region  152 . In  FIG. 5A , an area of the privacy information region  151  is A 1 , and a center position of the privacy information region  151  is P 1 . As shown in  FIG. 5B , when the window containing the privacy information is moved to a position P 2 , the privacy information region  151  is correspondingly moved to the position P 2 . As shown in  FIG. 5C , if the window containing the privacy information is enlarged at the position P 2 , the area of the privacy information region  151  is synchronously enlarged to an area A 2 , so as to achieve the effect of tracking the privacy information. 
       FIG. 4B  is a flowchart illustrating a privacy protecting method according to another embodiment of the invention. Referring to  FIG. 1  and  FIG. 4B , the control module  13  first determines whether to activate the privacy protecting mask  14 . If it is determined that it is unnecessary to activate the privacy protecting mask  14 , the display device  1  maintains the wide angle display state, and if it is determined that it is required to activate the privacy protecting mask  14 , a privacy information region is set in the display image and a viewing angle of the privacy information region is set (step S 31 ). Then, the display image analyzing module  12  continually detects whether the area or the position of the privacy information region is changed (step S 40 ), and if it is detected that the area or the position of the privacy information region is changed, the step S 50  is executed, by which the control module  13  accordingly changes the area and the position of the privacy protecting region, so as to correspondingly set a new privacy information region in the display image. 
     A range of the privacy information region may be set according to the area and the position of the window containing the privacy information, and the viewing angle of the privacy information region may be set according to a relative position between a stranger around the user and the display image. For example, the image sensing circuit  113  in the display device  1  may detect whether a stranger is approaching to the back of the user, and records a relative angle between the stranger behind the user and the display screen, so as to determine a viewing angle of the display image required to be switches. As shown in  FIG. 7A , it is assumed that the privacy information region  151  is located at the center position of the display image, when a stranger  16  is close to the privacy information region  151 , the display panel  15  is required to set a narrow viewing angle. When the stranger  16  is away from the privacy information region  151 , as shown in  FIG. 7B , the display panel  15  is required to set a larger viewing angle. 
       FIG. 4E  is a flowchart illustrating a privacy protecting method according to still another embodiment of the invention. In an embodiment, the image sensing circuit  113  captures an image of the user or other people around the user through a camera lens of the display device  1 , and the control module  13  detects the captured image to obtain a user position in the captured image (step S 302 ) or the control module  13  detects the captured image to obtain other people position in the captured image (step S 303 ). Then, the control module  13  controls the privacy protecting mask  14  according to the user position or other people&#39;s position in the captured image to correspondingly adjust the viewing angle of the privacy information region  151  (step S 304 ). Therefore, the control module  13  may monitor a relative position between the user and the others according to the captured image of the image sensing circuit  113 , so as to dynamically switch the viewing angle of the display device  1 . However, if it is found someone is just standing behind the user through the captured image, the control module  13  may also control the privacy protecting mask  14  to completely shield the privacy information presented by the display image, so as to prevent the privacy information from being peeped by others. 
       FIG. 4C  is a flowchart illustrating a determination flow for activating the privacy protecting mask according to an embodiment of the invention. Referring to  FIG. 1  and  FIG. 4C , the position detecting circuit  11  detects a position of the display device  1  to determine whether to activate the privacy protecting mask  14  (step S 20 ), for example, the positioning circuit  111  detects a horizontal position of the display device  1  while the height detecting circuit  112  detects a height of the display device  1  (step S 200 ) or position features of an environment image are captured (step S 202 ), for example, the image sensing circuit  113  captures the environment image of the display device  1 , and determines the position of the display device  1  according to obvious position features in the environment image, so as to determine whether to activate the privacy protecting mask  14  (step S 20 ). For example, the camera lens of the display device  1  may capture the environment image around the user, where the environment image may present position features such as a high building (for example, Taipei  101 ) or a LOGO of a specific company (for example, ACER), etc., and though the position features, it is learned whether the display device  1  is in a private or public place, so as to determine whether to activate the privacy protecting mask  14 . 
     Moreover, as shown in  FIG. 4C , the user also creates an exclusive mask database  10  in the display device  1 , and sets a specific privacy protecting strategy, and selects the privacy protecting strategy of the mask database (step S 201 ) to determine whether to activate the privacy protecting mask  14  (step S 20 ). For example, the user may sets an information list of the privacy protecting strategy in the mask database  10 , as that shown in a table  2 , the information list of the privacy protecting strategy may includes information such as an application name, a website address, a window title, whether the entire window is masked or only a sub window is masked, etc. The user may determine whether to activate the privacy protecting mask  14  according to different application types. When the user opens a website (for example, Brower in the table  2 ), the user may determine whether to activate the privacy protecting mask  14  according to the privacy protecting strategy of the website, and if the user opens a file (for example, MS word in the table  2 ), the user may determine whether to activate the privacy protecting mask  14  according to the privacy protecting strategy of the file. 
     
       
         
           
               
               
               
               
               
               
             
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 App. 
                   
                   
                 Total 
                 Sub window 
               
               
                   
                 name 
                 Website 
                 Window title 
                 mask 
                 information 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 1 
                 Brower 
                 https://salary.hq.- 
                 e-Payslip 
                 Yes 
                 None 
               
               
                   
                   
                 intra.acer.com/ 
                 System - 
               
               
                   
                   
                 UI/Common/ 
                 Internet Explorer 
               
               
                   
                   
                 Login.aspx 
               
               
                 2 
                 MS 
                 None 
                 PDLC.docx - 
                 Yes 
                 None 
               
               
                   
                 Word 
                   
                 Microsoft Word 
               
               
                   
               
            
           
         
       
     
     Moreover, a privacy protecting strategy related to privacy information features may be created in the mask database  10 . The privacy information features may include a text or an image of a password, a code number, an account number, log in, sign in, register, a birthday, a name, an ID number, a verification code, a dynamic keyboard, a software keyboard, a Password, Confidential, Secret, Sing In, etc., or other corresponding languages. If the display image only has the privacy information features, but the display image dose not has the privacy information, it is unnecessary to activate the privacy protecting mask  14 . For example, a key “log in” is generally presented on a home page of a bank website for user&#39;s inquiry, for example, to inquire transaction details of a credit card, and if the user only inquires public information of the bank, the user is unnecessary to click the key “log in”, so that the display image does not show any privacy information of the user, and now the control module  13  determines that it is unnecessary to activate the privacy protecting mask  14 . 
       FIG. 8  is a schematic diagram of a privacy protecting strategy of a mask database according to an embodiment of the invention. Since the privacy information and people have a corresponding relationship, it is required to create an identification list in the mask database  10  to serve as the privacy protecting strategy, so as to identify the corresponding relationship between each people (for example, family member, colleague, supervisor, stranger, etc.) and the privacy information. As shown in  FIG. 8 , when the mask database  10  is created for the first time, only the user may be able to view the privacy information, so that when other people is around the user, the privacy protecting mask  14  is automatically activated, and along with growing of a usage course, correspondence of a confidential state may be updated along with user&#39;s demand, for example, some information is non-confidential to family members, and when a family member is approaching the user, it is unnecessary to activate the privacy protecting mask  14 ; and some information is non-confidential to the supervisor, and when the supervisor is around the user, it is unnecessary to activate the privacy protecting mask  14 . 
       FIG. 4D  is a flowchart illustrating a determination flow for activating the privacy protecting mask according to another embodiment of the invention. Referring to  FIG. 1  and  FIG. 4D , the position detecting circuit  11  of the display device  1  may be further configured with a communication circuit  114 , and the communication circuit  114  is coupled to the control module  13 . In step S 203 , the positioning circuit  111  provides position information of the display device  1 , and the communication circuit  114  downloads at least one streetscape map from the Internet according to the position information provided by the positioning circuit  111  (step S 204 ). Then, the image sensing circuit  113  captures the environment image of the display device  1  (step S 205 ), and the control module  13  compares the environment image with the streetscape map (step S 206 ). Therefore, the control module  13  deduces an accurate position of the display device  1  according to the position information provided by the positioning circuit  111  and the comparison result, so as to determine whether to activate the privacy protecting mask  14  (step S 20 ). 
     For example, the communication circuit  14  may be a global system for mobile communication (GSM), a third generation (3G), or a fourth generation (4G) or wired or wireless network interface circuits of other mobile communication techniques. The communication circuit  14  may be connected to the Internet, and find the streetscape map of a street near the display device  1  according to address information detected by the positioning circuit  111 . The image sensing circuit  113  may determine whether clothing on characters in the environment image captured by the camera lens of the display device  1  includes a specific image or mark (for example, specific information such as an ID, a name, or a company name, etc.). The control module  13  compares the specific information with the streetscape map to seek same objects from the environment image and the streetscape map, so as to deduce the accurate position of the display device  1 . 
       FIG. 6  is a flowchart illustrating a privacy protecting method according to another embodiment of the invention. Referring to  FIG. 1  and  FIG. 6 , in step S 10 , the control module  13  first determines whether the display device  1  has the mask database  10 , and if the mask database  10  does not exist, the control module  13  creates the mask database  10  (step S 11 ). Since the display image analyzing module  12  may detect whether the display image includes a region required to be masked according to user&#39;s demand, when the display device  1  is used for the first time, the user requires to create the mask database  10  to store a privacy protecting strategy related to the mask. The user may set the types of information required to be masked in the mask database  10 , for example, booting login, a website login window, a specific application window, a game window, etc., and the windows are independent to each other. 
     It should be noted that in different application situations, related functions of the display image analyzing module  12  may be implemented as software, firmware or hardware by general programming languages (for example, C or C++), hardware description languages (for example, Verilog HDL or VHDL) or other proper programming languages. 
     If the mask database has been created by the user, the mask database may be read (step S 12 ). Then, the display image analyzing module  12  detects the application in execution (step S 13 ), and determines whether the display image contains privacy information features (step S 14 ). If the display image contains the privacy information features, positions of the user and others relative to the display image are detected (step S 21 ), so as to set a privacy protecting region according to a privacy information distribution status, and the relative relationship between the position of the user and the position of the others. 
     Then, the control module  13  sets a privacy information region in the display image and sets a viewing angle of the privacy information region (step S 31 ). For example, when a plurality of windows containing the privacy information is distributed at different positions of the display image, a plurality of privacy information regions is set in the display image. When others are close to the user, a narrow viewing angle is set. When others are away from the user, a large viewing angle is set. When the viewing angle and a range of the privacy information region are set, the display image analyzing module  12  continually detects whether an area or a position of the privacy information region is changed (step S 40 ), if it is detected that area or the position of the privacy information region is changed, a step S 50  is executed, by which the control module  13  correspondingly changes the area or the position of the privacy protecting region, so as to set a new privacy information region in the display image. 
     In summary, the display device and the privacy protecting method thereof of the embodiments of the invention may integrate the PDLC, the GPS positioning device, the height detector, the image detector, etc. in the system through software, and automatically detect whether an application has specific privacy information according to an actual environment condition, so as to adjust a viewing angle of a part of region of the display image to achieve the effect of privacy protection. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.