Patent Publication Number: US-10762871-B2

Title: Image control method and image display device

Description:
TECHNICAL FIELD 
     The present invention relates to an image display method and an image display device for displaying an image such as a display, a projector or the like. 
     BACKGROUND ART 
     When an image display apparatus displays on a display screen a video signal input from another device, the user viewing the display screen performs settings and adjustments to the display image such as the color of the display image displayed on the display screen, the position of the display image in the horizontal and vertical directions, contrast, brightness and the like in accordance with an OSD (On Screen Display) menu. 
     The OSD menu is displayed as an image superimposed on a predetermined area in the display image based on an input video signal. The user performs the aforementioned settings and adjustments to the display image by operating the image of the OSD menu in the display image with a button or knob or a touch panel or the like of the image display device main body. 
     When displaying an image of the OSD menu, the image display device performs a process of superimposing, that is, combining, the image of the OSD menu on a display image based on an input video signal for display as a composite image on the display screen. 
     Here, the resolution during display of the composite image in which the image of the OSD menu is combined is also determined based on the respective frequencies of the vertical synchronization signal and the horizontal synchronization signal of the display image based on the video signal. The frequency of each of the vertical synchronization signal and the horizontal synchronization signal is detected from the video signal supplied to the image display device. 
     For this reason, when the video signal is no longer supplied due to a sudden loss of the video signal supply source or the like, the respective frequencies of the vertical synchronization signal and the horizontal synchronization signal for displaying the display image based on the video signal cannot be obtained. Thereby, the image display device cannot determine the resolution of the display image based on the video signal, cannot generate the display image to be displayed on the display screen, and can no longer continue the process of displaying on the display screen the composite image in which the OSD menu is superimposed. 
     Therefore, even when the user is displaying the image of the OSD menu and setting and adjusting the display image of the display screen, when the supply of the video signal is lost, the image display device can no longer display the composite image, and so the display screen darkens to an all-black state. As a result, the OSD menu is not displayed either, and the usability in setting and adjusting the display image of the display screen is impaired. 
     In addition, when the respective frequencies of the vertical synchronization signal and the horizontal synchronization signal cannot be detected from the image of the image signal during startup of the image display device or when the format of the image signal has changed, since the display image cannot be normally displayed the image of the OSD menu is also not displayed. 
     In order to deal with a video signal in which the respective frequencies of the vertical synchronization signal and the horizontal synchronization signal described above cannot be detected, there is disclosed an image display device that requests a video signal for adjustment from the supply source of the video signal, detects the respective frequencies of the vertical synchronization signal and the horizontal synchronization signal from the video signal for adjustment, and displays the display image (see, for example, Patent Document 1). 
     PRIOR ART DOCUMENTS 
     Patent Documents 
     [Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2002-41010 
     SUMMARY OF THE INVENTION 
     Problem to be Solved by the Invention 
     However, the display device of Patent Document 1, by dealing with the case where the video signal supply source is not lost, cannot cope with the case in which the video signal is no longer supplied. 
     Therefore, the image of the OSD menu is not displayed during startup of the image display device and when the format of the video signal has changed. The problem of usability in the setting and adjustment of the display image in the display screen being impaired is thus not solved. 
     In view of the above-described problems, an object of the present invention is to provide an image display method and an image display device that, during setting and adjusting of a display image in a display screen by the OSD menu, displays the OSD menu on the display screen until the completion of the setting and adjustment in the OSD menu even if the video signal is no longer supplied. 
     Means for Solving the Problem 
     The present invention is an image display method for combining an image of an on-screen display (OSD) menu with a display image that is based on an input video signal, and displaying a combined composite image, the OSD menu having an OSD function and performing predetermined setting, the method including: when the video signal is not input in a state in which setting in the image of the OSD menu is performed, displaying a composite image obtained by recombining the image of the OSD menu with the composite image displayed immediately prior thereto. 
     The present invention is an image display device for combining an image of an OSD menu with a display image that is based on an input video signal, and displaying a combined composite image, the OSD menu having an OSD function and performing predetermined setting, the device including: a combining unit that combines the image of the OSD menu with the display image; an image control unit that, when the video signal is not input in a state in which setting in the image of the OSD menu is performed, displays a composite image obtained by recombining the image of the OSD menu with the composite image displayed immediately prior thereto; and an image output unit that displays the composite image. 
     Effect of the Invention 
     According to the present invention, even when the video signal is no longer supplied while setting and adjustment of the display image in the display screen are being performed from the OSD menu, since the composite image that is obtained by combining the OSD menu with the display image based on a video signal that was displayed immediately prior to the video signal no longer being supplied continues to be displayed until the end of the setting and adjustment in the OSD menu, it is possible to improve the usability compared to before due to the OSD menu being displayed in the display screen during setting and adjustment of the display image. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a drawing showing a configuration example of the image display device  1  according to an exemplary embodiment of the present invention. 
         FIG. 2  is a flowchart showing a processing example in which the image display device  1  displays in the display screen a composite image obtained by combining the display image and the image of the OSD menu. 
         FIG. 3  is a drawing for describing the concept of the exemplary embodiment of the present invention. 
     
    
    
     EMBODIMENTS FOR CARRYING OUT THE INVENTION 
     Hereinbelow, an image display device according to an exemplary embodiment of the present invention will be described with reference to the drawings.  FIG. 1  is a drawing showing a configuration example of an image display device  1  according to an exemplary embodiment of the present invention. 
     As shown in  FIG. 1 , the image display device  1  is provided with a video signal input unit  101 , an input switching unit  102 , a pixel conversion unit  103 , a menu operation unit  104 , a display image control unit  105 , an image combining unit  106 , a menu image generation unit  107 , a first storage unit  108 , a second storage unit  109 , an image output unit  110 , and an image display unit  111 . 
     The video signal input unit  101  has a video input interface (input system) that accommodates video signals (IN # 1 , IN # 2 , . . . , IN # n) of a plurality of different transmission formats in the digital format and the analog format. When the video signal is in the analog format, the video signal input unit  101  converts the video signal to a video signal in the digital format (IIN # 1 , IIN # 2 , . . . , IIN # n) and then outputs the converted signal. Here, examples of digital transmission formats include, for example, DVI (Digital Visual Interface)-D, IEEE 1394, HDMI (registered trademark, High-Definition Multimedia Interface), Ethernet (registered trademark), and SCSI (Small Computer System Interface). Examples of analog transmission formats include S terminal, D terminal, VGA (Video Graphics Array), and DVI-I. 
     The input switching unit  102  performs switching whether to output any one of the video signals (IIN # 1 , IIN # 2 , . . . , IIN # n) supplied from the video signal input unit  101  to the pixel conversion unit  103  in the subsequent stage, in other words, whether to use the video signal as a display image. Here, the input switching unit  102  performs switching of an output terminal in accordance with switching control from a control unit (not shown), and outputs any one of the video signals (IIN # 1 , IIN # 2 , . . . , IIN # n) supplied from the video signal input unit  101  to the pixel conversion unit  103 . 
     The pixel conversion unit  103  extracts data of a display image from the video signal supplied from the input switching unit  102  and outputs the data. Also, the pixel conversion unit  103  calculates the resolution and synchronization (horizontal synchronization and vertical synchronization) timing of the display image based on the synchronization signals (horizontal synchronization signal and vertical synchronization signal) included in the video signal, and outputs the data of the display image in accordance with this resolution. Here, the pixel conversion unit  103  outputs the data of the display image, and the calculated resolution and synchronization (horizontal synchronization and vertical synchronization) timing of the display image to the display image control unit  105 . 
     The display image control unit  105  determines whether the video signal is normally input from the input switching unit  102  based on the resolution supplied from the pixel conversion unit  103 . Here, the display image control unit  105  determines that the video signal is normally input when the resolution is within the normal value range. On other hand, when the resolution is not within the normal value range, the display image control unit  105  determines that the video signal is normally input. 
     In addition, when the video signal of the frame to be displayed next on the display screen has been input from the pixel conversion unit  103 , the display image control unit  105  causes a composite image that is currently displayed in the display screen and stored in the first storage unit  108  to be written to and stored in the second storage unit  109 . 
     At the point in time at which the display image control unit  105  has detected that a video signal is not input normally, when a predetermined setting process is being performed by the menu operation unit  104 , the display image control unit  105  writes to and stores in the first storage unit  108  blank data that makes all pixels black, being of the same resolution as the resolution stored in the first storage unit  108 . 
     The display image control unit  105  compares the data stored in each of the first storage unit  108  and the second storage unit  109 . When blank data is not written in the first storage unit  108 , the display image control unit  105  determines that a setting process by the OSD menu is being performed and the video signal has not been lost. When a setting process by the OSD menu is being performed and the video signal has not been lost, the display image control unit  105  outputs the data of the input display image to the image combining unit  106 , and causes the data of the composite image supplied from the image combining unit  106  to be written to and stored in the first storage unit  108 . 
     On the other hand, when blank data is written in the first storage unit  108  and a composite image is stored in the second storage unit  109 , the display image control unit  105  determines that a setting process by the OSD menu is being performed but the video signal is lost. The display image control unit  105  outputs the data of the composite image stored in the second storage unit  109  to the image combining unit  106 , and causes the data of the composite image supplied from the image combining unit  106  to be written to and stored in the second storage unit  108 . 
     Further, the display image control unit  105  causes the image combining unit  106  to generate a composite image in synchronization with the synchronization (horizontal synchronization and vertical synchronization) timing calculated by the pixel conversion unit  103 . 
     The image combining unit  106  combines (in the case of a display image) or recombines (in the case of a composite image) the image of the OSD menu supplied from the menu image generation unit  107  with a display image or a predetermined image area of a composite image supplied from the display image control unit  105  and outputs the result as a composite image to the display image control unit  105 . At this time, the image combining unit  106  generates a composite image by matching the resolution of the OSD menu image with the resolution of the display image or the composite image supplied from the display image control unit  105 . 
     The menu image generation unit  107  generates an OSD menu screen corresponding to an operation signal for performing a predetermined setting process supplied from the menu operation unit  104  and outputs the result to the image combining unit  106 . When an input video signal is displayed on the display screen, this OSD menu is used for performing setting and adjustment to the display image such as the color of the display image displayed on the display screen, the position in the horizontal and vertical directions of the display image, contrast, brightness and the like. 
     The menu operation unit  104  outputs to the menu image generation unit  107  an operation signal indicating that the OSD menu be displayed by, for example, the user pressing an OSD button for reading the OSD menu. Further, when a predetermined key operation or button operation is performed, the menu operation unit  104  outputs an operation signal corresponding to the key operation or button operation to the menu image generation unit  107 . While an operation by the OSD menu is being performed by the user, that is, until the user presses the button for clearing the OSD menu, an operation continuation signal indicating that a process of a predetermined setting by the OSD menu is being performed is output to the display image setting unit  105 . Each of the keys and buttons is provided in the main body of the image display device  1  or in a remote controller for operating the image display device  1  or the like. 
     Each of the first storage unit  108  and the second storage unit  109  is, for example, a VRAM (Video Random Access Memory), being memory for storing image data for displaying an image in the image display device. In the present exemplary embodiment, a display image or a composite image is written and stored therein. 
     The image output unit  110  outputs to the image display unit  111  one of the data of the display image or composite image stored in the first storage unit  108  and data of the composite image stored in the second storage unit  109  with a control signal from the display image control unit  105 . 
     The image display unit  111  is, for example, a liquid crystal display panel or a liquid crystal panel of a projector. 
       FIG. 2  is a flowchart showing an example of processing in which the image display device  1  displays on the display screen a composite image obtained by combining the display image and the image of the OSD menu. 
     Step S 1 : 
     The video signal input unit  101  outputs each of the video signals (IN # 1 , IN # 2 , . . . , IN # n) that have been input to the input switching unit  102  as the video signals (IIN # 1 , IIN # 2 , . . . , IIN # n), respectively. 
     Then, the input switching unit  102  supplies a video signal set by the control unit to the pixel conversion unit  103  from the video signals (IIN # 1 , IIN # 2 , . . . , IIN # n). 
     Step S 2 : 
     The pixel conversion unit  103  extracts data of the display image from the supplied video signal, and outputs the data of the extracted display image to the display image control unit  105 . Also, the pixel conversion unit  103  extracts synchronization signals (horizontal synchronization signal and vertical synchronization signal) from the video signal, and calculates the synchronization (horizontal synchronization and vertical synchronization) timing on the basis of the synchronization signals. Further, the pixel conversion unit  103  calculates (extracts) the resolution of the display image using each of the horizontal synchronization signal and the vertical synchronization signal. 
     Step S 3 : 
     The display image control unit  105  determines whether the resolution calculated by the pixel conversion unit  103  is within a predetermined numerical range, that is, whether the video signal is irregular. At this time, when the resolution is within the predetermined numerical range, the display image control unit  105  determines that the video signal is not irregular, and advances the process to Step S 5 . On the other hand, when the resolution is not within the predetermined numerical range, the display image control unit  105  determines that the video signal is irregular, and advances the process to Step S 4 . 
     Step S 4 : 
     If the display image control unit  105  determines that the video signal is irregular, the display image control unit  105  writes and stores blank data in the first storage unit  108  instead of data of a display image or a composite image. 
     Step S 5 : 
     The display image control unit  105  determines whether an operation continuation signal is supplied from the menu operation unit  104 , that is, determines whether a predetermined setting process is being performed using the OSD menu. When the operation continuation signal is being supplied, since a predetermined setting process is being performed using the OSD menu, the display image control unit  105  advances the process to Step S 6 . On the other hand, when the operation continuation signal is not being supplied, since a predetermined setting process is not being performed using the OSD menu, the display image control unit  105  advances the process to Step S 12 . 
     Step S 6 : 
     The menu image generation unit  107  generates an image of the OSD menu corresponding to the operation signal supplied from the menu operation unit  104 . Then, the menu image generation unit  107  outputs the generated image of the OSD menu to the image combining unit  106 . 
     Step S 7 : 
     The display image control unit  105  confirms each set of data of the first storage unit  108  and the second storage unit  109 , and determines whether the video signal has been lost. Here, the display image control unit  105  confirms whether the display image (or composite image) of the frame currently displayed and the display image (or composite image) of the frame displayed immediately prior thereto are stored in the first storage unit  108  and the second storage unit  109 , respectively. 
     At this time, when the display image (or composite image) of the frame currently displayed and the display image (or composite image) of the frame displayed immediately prior thereto are stored in the first storage unit  108  and the second storage unit  109 , respectively, the display image control unit  105  advances the process to Step S 8 . On the other hand, when blank data is written in the first storage unit  108  and the display image (or composite image) of the frame displayed immediately prior thereto is stored in the second storage unit  109 , the display image control unit  105  advances the process to Step S 9 . 
     Step S 8 : 
     The display image control unit  105  outputs the data of the display image supplied from the pixel conversion unit  103  to the image combining unit  106  in accordance with the synchronization timing. 
     The image combining unit  106  combines the display image supplied from the display image control unit  105  and the image of the OSD menu supplied from the menu image generation unit  107 , and outputs the combined image as a composite image to the display image control unit  105 . Then, after generating the composite image, the display image control unit  105  advances the process to Step S 12 . 
     Step S 9 : 
     The display image control unit  105 , referring to the second storage unit  109 , reads the composite image displayed in the immediately preceding frame, and outputs the data of the read-out composite image to the image combining unit  106  in accordance with the synchronization timing. 
     The image combining unit  106  recombines the image of the OSD menu supplied from the menu image generation unit  107  with the composite image displayed in the immediately preceding frame supplied from the display image control unit  105 , and outputs the recombined image as a composite image to the display image control unit  105 . Then, after generating the composite image, the display image control unit  105  advances the process to Step S 10 . 
     Step S 10 : 
     The image combining unit  106  writes to and stores in the second storage unit  109  the data of the recombined image as the composite image, and performs a data update of the second storage unit  109 . 
     Step S 11 : 
     The display image control unit  105  outputs a control signal causing the image output unit  110  to display the data of the composite image stored in the second storage unit  109 , and advances the process to Step S 1 . 
     Thereby, the image output unit  110  reads out data of the composite image from the second storage unit  109  in accordance with the synchronization timing, and outputs the data to the image display unit  111 . 
     Then, the image display unit  111  displays a composite image obtained by recombining the image of the OSD menu with the composite image on the display screen. 
     Step S 12 : 
     The image combining unit  106  combines the video signal supplied from the display image control unit  105  and the image of the OSD menu supplied from the menu image generation unit  107 , writes to and stores in the first storage unit  109  the data of the combined composite image, and updates the data in the first storage unit  108 . 
     Step S 13 : 
     The display image control unit  105  outputs to the image output unit  110  a control signal causing the display of data of a display image (when a setting by the OSD menu is not performed) or a composite image (when a setting by the OSD menu is performed) stored in the first storage unit  108 , and advances the process to Step S 14 . 
     Thereby, the image output unit  110  reads data of the display image or composite image from the first storage unit  109  in accordance with the synchronization timing, and outputs the data to the image display unit  111 . 
     The image display unit  111  displays as a predetermined frame on the display screen a composite image obtained by recombining the image of the OSD menu with the display image or the constructed image. 
     Step S 14 : 
     The display image control unit  105  writes to the second storage unit  109  the data of the display image or the composite image stored in the first storage unit  108 . That is, the display image control unit  105  copies the data of the first storage unit  108  to the second storage unit  108 . Then, display image control unit  105  advances the process to Step S 1 . 
     When a video signal is normally supplied by the above-described processing, and the processing of a predetermined setting is not performed by the OSD menu, the display image of the frame displayed in the image display unit  111  is stored in the first storage unit  108 . A display image of a frame immediately prior to the frame displayed in the image display unit  111  is stored in the second storage unit  109 . Further, when a video signal is normally supplied, and the processing of a predetermined setting is performed by the OSD menu, the composite image of the frame displayed in the image display unit  111  is stored in the first storage unit  108 . A composite image of the frame immediately prior to the frame displayed on the image display unit  111  is stored in the second storage unit  109 . 
     In addition, when a video signal is not supplied normally and the processing of a predetermined setting is not performed by the OSD menu, blank data is stored in each of the first storage unit  108  and the second storage unit  109 . Further, when a video signal is not normally supplied and the processing of a predetermined setting is performed by the OSD menu, blank data is stored in the first storage unit  108 . Further, a composite image of the frame displayed in the image display unit  111  immediately prior to detection of the fact that a video signal is not normally supplied is stored in the second storage unit  109 . 
     With the above-described configuration, according to the present exemplary embodiment, when a video signal is no longer supplied from an external device while a predetermined setting processing by the OSD menu is being performed, since a composite image in the second storage unit  109  is supplied to the image combining unit  106  as a display image combining the image of the OSD menu, and a composite image obtained by recombining the image of the OSD menu according to the resolution of this composite image is displayed in the image display unit  11 , it becomes possible to continue a predetermined setting process by the OSD menu. Also, the situation is eliminated in which the setting process by the OSD menu can no longer be performed due to the image of the OSD menu no longer being displayed in the image display unit  111  at the point at which the video signal is no longer supplied, as is conventional, and so the usability of the user setting process can be improved. 
       FIG. 3  is a drawing for describing the concept of the exemplary embodiment of the present invention. In  FIG. 3 , the image display device  1  according to the exemplary embodiment of the present invention is an image display device for combining an image of an OSD menu, which has an OSD function and which performs predetermined setting, with a display image based on an input video signal, and displaying a combined composite image, being provided with the display image control unit  105 , the image combining unit  106 , and the image output unit  110 . In the image display device  1 , when a predetermined setting processing by the OSD menu is being performed, as an image obtained by the image combining unit  106  combining the image of the OSD menu, the display image control unit  105 , when a video signal is normally supplied, outputs the display image extracted from this video signal to the image combining unit  106 , and when a video signal is not normally supplied, outputs to the image combining unit  106  a composite image of the frame stored immediately prior thereto. 
     Thereby, when the video signal is no longer normally supplied while a predetermined setting processing by the OSD menu is being performed, since the image of the OSD menu is recombined with a stored composite image, and the recombination result is output from the image output unit  110 , the OSD menu suddenly no longer being displayed in the conventional manner ceases to happen. The user can therefore continue the predetermined setting processing with the image of the OSD menu displayed on the display screen of the image display device, and so the usability for the user is enhanced. 
     The process of correcting display unevenness in the liquid crystal panel in the image display device of  FIG. 1  may be performed by an external computer system for realizing the control function of the image display device. Note that a “computer system” here includes an operating system and hardware such as peripheral devices. 
     Although exemplary embodiments of the present invention have been described in detail with reference to the drawings, specific constitutions are not limited to the present exemplary embodiments, and designs within a range that does not depart from the gist of the invention are included. 
     INDUSTRIAL APPLICABILITY 
     The image display method and the image display device described above can be applied to a device for displaying an image having an OSD function. In particular, the image display method and the image display device are suitable for applications such as a display device and projector device in which a predetermined setting process by an OSD menu is provided as a standard function, as a device whose usability is improved by continuously displaying an image of a menu even if supply of a video signal is lost during setting. 
     REFERENCE SYMBOLS 
     
         
         
           
               1 : Image display device 
               101 : Video signal input unit 
               102 : Input switching unit 
               103 : Pixel conversion unit 
               104 : Menu operation unit 
               105 : Display image control unit 
               106 : Image combining unit 
               107 : Menu image generation unit 
               108 : First storage unit 
               109 : Second storage unit 
               110 : Image output unit 
               111 : Image display unit