Patent Publication Number: US-2011050850-A1

Title: Video combining device, video display apparatus, and video combining method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2009-200812, filed on Aug. 31, 2009, the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Field 
     Embodiments described herein relate generally to a video combining device, a video display apparatus, and a video combining method for generating and displaying a graphic object such as an on-screen display image. 
     2. Description of the Related Art 
     In recent years, TV receivers and video, monitors having a function of displaying a stereographic (3D) video content have spread widely. And, many 3D video contents have come to be provided by many broadcasting companies and content servers on the Internet. In many cases, a 3D video signal of a 3D video content is different from a two-dimensional (2D) video signal of a common 2D video content. For practice use of such a 3D video signal, various techniques have been disclosed or implemented. 
     For example, JP-2007-110683-A (FIG. 1 and Paragraph 0025) discloses a technique for controlling the opening/closing timing of electronic shutters in a 3D video apparatus including a storage/overwriting-type display (such as an LCD which is commonly available on the market) and glasses having electronic shutters. 
     On the other hand, TV receivers and video monitors which display a video signal of a 2D video content and the provision of 2D video contents are still common. Therefore, it is preferable to provide a technique for displaying 3D video and 2D video in a switched manner. 
     For example, JP-2007-213081-A (FIG. 4 and Paragraphs 0036 and 0037) discloses a technique relating to a 3D image display apparatus capable of displaying 2D video and 3D video in a switched manner. This technique can attain higher display quality and switching of higher speed than before and display a 2D image and a 3D image in a mixed manner in an arbitrarily selected area. 
     However, in JP-2007-110683-A, the opening/closing times of the electronic shutters are short. As a result, the luminance of displayed video is low and hence a 3D image can be displayed only in a restricted area of the screen. In the area where the 3D image cannot be displayed, information such as a logo and an explanation text relating to the 3D image is displayed as an on-screen display (OSD) image which is a graphic object. In other words, this OSD image is displayed as a non-3D image. 
     In JP-2007-213081-A, to display a 2D image and a 3D image in a switched manner, there are provided liquid crystal lenses as a birefringent lens array and a half-wave film or a ferroelectric liquid crystal cell as a birefringent phase modulating means. The lens effect of the birefringent lens array and the birefringent phase modulating means is controlled by a voltage. A 2D image and a 3D image are displayed in a switched manner by such a complex configuration. There is no disclosure as to a graphic object to be displayed combinedly with a 2D image or a 3D image. 
     That is, conventionally, although an input video signal can be displayed as 3D video or 2D video in a switched matter depending on the type of the input video signal, a graphic object that is not included in the input video signal cannot be displayed as 3D video or 2D video in the switched matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A general architecture that implements the various feature of the present invention will now be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the present invention and not to limit the scope of the present invention. 
         FIG. 1  illustrates an example configuration of a TV receiver according to a first embodiment. 
         FIG. 2  illustrates an example system block configuration according to the first embodiment for superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal and controlling the 3D glasses. 
         FIG. 3  illustrates an example process for superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal. 
         FIG. 4  illustrates an example 3D video signal. 
         FIG. 5  illustrates another example 3D video signal. 
         FIG. 6  illustrates an example image frame groups which are generated from an input 3D video signal through frame rate conversion and image frame rearrangement and are to be output to a display unit. 
         FIG. 7  illustrates an another image frame groups that are generated from an input 3D video signal through frame rate conversion and image frame rearrangement and are to be output to the display unit. 
         FIG. 8  illustrates an example timing chart for the output control of a 3D video signal to the display unit and the opening/closing control of shutters of the 3D glasses. 
         FIG. 9  illustrates an example system block configuration according to a modification of the first embodiment for superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal and controlling the 3D glasses. 
         FIG. 10  illustrates an example system configuration according to a second embodiment for superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal and controlling the 3D glasses. 
         FIG. 11  illustrates an example process for superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments according to the present invention will be described hereinafter with reference to the accompanying drawings. In general, according to one embodiment of the present invention, there is provided a video combining device including: a frame extraction module configured to extract, from a 3D video signal including a left-eye video signal and a right-eye video signal, left-eye frames and right-eye frames; a graphic object generation module configured to generate a left-eye object to be superimposedly displayed on a screen with the left-eye frames and to generate a right-eye object to be superimposedly displayed on the screen with the right-eye frames; a combined image generation module configured to generate combined left-eye frames by synchronizedly combining the left-eye object and the left-eye frames and to generate combined right-eye frames by synchronizedly combining the right-eye object and the right-eye frames; a frame group generation module configured to generate a left-eye frame group in which the number of frames is increased and a right-eye frame group in which the number of frames is increased by performing a frame interpolation based on the combined left-eye frames and the combined right-eye frames generated by the combined image generation module; and an image output module configured to alternately output the left-eye frame group and the right-eye frame group so as to sequentially rewrite a display on the screen so that the left-eye frame group and the right-eye frame group are alternately displayed on the screen. 
     First Embodiment 
     A first embodiment of the present invention will be hereinafter described with reference to the drawings. 
       FIG. 1  illustrates the example configuration of a TV receiver  10  which is a video display apparatus incorporating a video combining device according to the first embodiment. 
     The TV receiver  10  according to the first embodiment includes a broadcast-wave processing section  20 , an external device IF (interface) section  31 , a signal processing control section  40 , a manipulation unit  51 , a light receiving unit  52 , a display unit  61 , speakers  62 , a shutter control section  81 , etc. The display unit  61  includes a liquid crystal panel  101 , a backlight  102 , etc. An antenna AT is connected to the broadcast-wave processing section  20 . The light receiving unit  52  exchanges information with a remote controller RC, and the shutter control section  81  exchanges information with 3D glasses EG. 
     The TV receiver  10  acquires a signal of stereographic video (3D video) or ordinary non-stereographic video (2D video) which is supplied via the broadcast-wave processing section  20 , the external device IF  31 , or the like. The TV receiver  10  generates an OSD image signal for displaying a 3D or 2D graphic object (a text, a figure, etc.) according to the acquired 3D or 2D video signal, superimposes the generated OSD image signal on the acquired 3D or 2D video signal, and displays a resulting signal on the display unit  61 . The TV receiver  10  controls the opening/closing of the shutters of the 3D glasses EG according to the acquired 3D or 2D video signal. 
     The broadcast-wave processing section  20  acquires signals of digital broadcast waves and analog broadcast waves received by the antenna AT, performs processing of tuning in to a signal on a particular channel of the acquired signals, performs demodulation and decoding processing on the selected signal, and outputs video data and audio data of a program, data to be used for generating an electronic program guide (EPG), and other data to the signal processing control section  40 . In the first embodiment, the broadcast-wave processing section  20  acquires signals including a 3D video signal or a 2D video signal. 
     Through the external device IF  31 , an external apparatus is connected to the TV receiver  10  via one of connection ports which comply with various standards such as the HDMI (trademark) standard, the USB standard, and the IEEE 1394 standard, acquires video data and audio data, data to be used for generating an EPG, and other data that are supplied from the connected external apparatus, and outputs the acquired data to the signal processing control section  40 . Furthermore, to the external device IF  31 , an external recording medium such as an external HDD or a memory card is connected to the TV receiver  10  via one of the connection ports which comply with the various standards such as the HDMI standard, the USB standard, and the IEEE 1394 standard and outputs or inputs video data and audio data etc. to or from the connected recording medium. Through the external device IF  31 , a signal including a 3D video signal or a 2D video signal is acquired from an external device located outside the TV receiver  10 . 
     The manipulation unit  51  receives manipulation input information to be used for manipulating the TV receiver  10  and outputs it to the signal processing control section  40 . Likewise, the light receiving section  52  optically receives the manipulation input information from the remote controller RC and outputs it to the signal processing control section  40 . 
     The signal processing control section  40  performs various kinds of processing such as expansion of compressed data and data extraction processing for generating an EPG on a signal acquired from the broadcast-wave processing section  20 , the external IF section  31 , or the like according to manipulation input information received from the manipulation unit  51  or the light receiving unit  52 . The signal processing control section  40  performs various kinds of processing such as MPEG coding/decoding processing and processing of separating a video signal and an audio signal on the received signal (data) and outputs a video signal and an audio signal to the display unit  61  and the speakers  62 , respectively. The signal processing control section  40 , which has a CPU, controls execution of plural pieces of processing using modules that are provided in or connected to the signal processing control section  40 . 
     In the first embodiment, the signal processing control section  40  performs prescribed processing on a signal including a 3D video signal or a 2D video signal acquired from the broadcast-wave processing section  20  or the external device IF  31 , or the like and displays 3D video or 2D video on the display unit  61 . The signal processing control section  40  generates a 3D or 2D OSD image signal according to the acquired 3D or 2D video signal, superimposes the generated OSD image signal on the acquired 3D or 2D video signal, and displays a resulting signal on the display unit  61 . The signal processing control section  40  outputs, to the shutter control section  81 , information for the opening/closing control of the shutters of the 3D glasses EG according to the acquired 3D or 2D video signal. 
     The display unit  61  is a display module for displaying a video signal received from the signal processing control section  40  and is, for example, a flat display such as an LCD (liquid crystal display). The display unit  62  displays a video signal received from the signal processing control section  40  on a liquid crystal panel  101 . The liquid crystal panel  101  is a light-transmission-type video display panel and turns on or off the backlight  102  according to a control signal supplied from the signal processing control section  40 . Although an LCD is exemplified as the display unit  61 , the embodiment is not limited thereto. 
     In the liquid crystal panel  101 , plural pixels are arranged in a matrix of a prescribed size. The liquid crystal panel  101  displays video by sequentially rewriting the display on the screen by performing scans along prescribed scanning lines according to a video signal received from the signal processing control section  40 . 
     The backlight  102  illuminates the liquid crystal panel  101  from its back side as a light source. A direct facing type cold cathode fluorescent tube or a direct facing type or side illumination type EL (electroluminescence) device(s) or LEDs may be used as the backlight  102 . In the first embodiment, the backlight  102  is a direct facing type or side illumination type LED light source and is turned on/off according to control information supplied from the signal processing control section  40 . 
     The speakers  62  output a sound according to an audio signal that is received from the signal processing control section  40 . 
     The shutter control section  81  outputs shutter control signals for the opening/closing control of the left-eye shutter and the right-eye shutter of the 3D glasses EG according to information received from the signal processing control section  40 . Although the shutter control section  81  is exemplified as being provided separately from the signal processing control section  40 , it may be incorporated in the signal processing control section  40 . 
     Although the TV receiver  10  is exemplified, the embodiment can also be applied to an HDD recorder, a DVD recorder, a personal computer, a cell phone, or the like including the same configuration as described in the first embodiment. The embodiment can further be applied to, for example, a set top box configured to receive not only TV broadcasts including satellite broadcasts but also radio broadcasts, cable broadcasts using the Internet or the like, and other broadcasts. 
     Having the above example configuration, the TV receiver  10  acquires a 3D or 2D video signal, generates a 3D or 2D OSD image signal according to the acquired 3D or 2D video signal, superimposes the generated OSD image signal on the acquired 3D or 2D video signal, and displays a resulting signal on the display unit  61 . The TV receiver  10  controls the opening/closing of the shutters of the 3D glasses EG according to the acquired 3D or 2D video signal. 
     The signal processing control section  40  performs the above processing, based on a video signal acquired from the broadcast-wave processing section  20 , the external device IF section  31 , or the like. 
     Next, individual blocks, which are mainly provided in the signal processing control section  40  shown in  FIG. 1 , to perform processing of superimposing a 3D or 2D OSD image signal on an input video signal depending on the type of the input video signal to display a resulting signal and processing of controlling the 3D glasses EG will be described with reference to  FIG. 2 . 
       FIG. 2  illustrates the example system block configuration according to the first embodiment for superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal and controlling the 3D glasses EG. 
     The system configuration of  FIG. 2  provides a video combining device. The video combining device may be provided separately from the signal processing control section  40 . 
     The signal processing control section  40  according to the first embodiment includes a signal judging section  201 , an OSD image generating section  211 , a left-eye OSD buffer  212 , a right-eye OSD buffer  213 , a selector  214 , a left/right image separating section  221 , blending sections  222  and  223 , a frame rate converting section  224 , a display disabling section  231 , etc. 
     The signal judging section  201  judges whether an input video signal is of 3D video or 2D video and outputs a judgment result to other blocks. For example, the judgment may be made based on information indicating a type of a video signal that is supplied from an external apparatus connected to the HDMI-compatible connection port via the external device IF section  31 . More specifically, the information referred for the judgment may be acquired through a negotiation of a connection authentication when the HDMI-compatible external apparatus is connected, in accordance with a protocol of 3D video data transfer defined in version 1.4 of the HDMI standard. 
     The signal judging section  201  can also make a judgment by detecting whether or not an input video signal supplied from the broadcast-wave processing section  20 , the external device IF section  31 , or the like has a feature of 3D video by performing one or plural ones (in a composite manner) of detection of 3D content identification information contained in information relating to coding of the input video signal, detection of an image format that is unique to 3D video of, for example, the side-by-side method which utilizes a parallax between the two eyes, and other kinds of detection. Thus, the judging method is not limited to a particular one. 
     If the signal judging section  201  judges that the input video signal is of 3D video, the OSD image generating section  211  generates a left-eye OSD image signal and a right-eye OSD image signal and outputs them to the left-eye OSD buffer  212  and the right-eye OSD buffer  213 , respectively. If the signal judging section  201  judges that the input video signal is of 2D video, the OSD image generating section  211  generates a 2D OSD image signal and outputs it to the right-eye OSD buffer  213 . 
     If the signal judging section  201  judges that the input video signal is of 3D video, the left-eye OSD buffer  212  stores the left-eye OSD image signal that is input from the 
     OSD image generating section  211  and outputs it to the selector  214  with prescribed timing. If the signal judging section  201  judges that the input video signal is of 2D video, the left-eye OSD buffer  212  stores nothing because no signal is input from the OSD image generating section  211 . 
     The right-eye OSD buffer  213  stores the right-eye OSD image signal corresponding to the 3D video or the 2D OSD image signal corresponding to the 2D video that is input from the OSD image generating section  211 , and outputs it to the selector  214  and the blending section  223  with prescribed timing. 
     If the signal judging section  201  judges that the input video signal is of 3D video, the selector  214  is set to output, to the blending section  222 , the left-eye OSD image signal that is input from the left-eye OSD buffer  212 . On the other hand, if the signal judging section  201  judges that the input video signal is of 2D video, the selector  214  is set to output, to the blending section  222 , the 2D OSD image signal that is input from the right-eye OSD buffer  213 . 
     If the signal judging section  201  judges that the input video signal is of 3D video, the left/right image separating section  221  separates the input 3D video signal into two sets of image frames by extracting a left-eye video signal (left-eye image frames) and a right-eye video signal (right-eye image frames) from the image frames of the input 3D video signal by performing prescribed processing on a frame-by-frame basis and outputs the two sets of image frames to the respective blending sections  222  and  223 . The left-eye video signal and the right-eye video signal are multiplexed according to an encoding method such as a method in which they are assigned to odd-numbered scanning lines and even-numbered scanning lines, respectively, or a method in which they are assigned to a left-hand area and a right-hand area of each image frame, respectively. Or the left-eye video signal and the right-eye video signal are multiplexed according to an encoding method such as a method in which square areas each having a prescribed number of pixels are arranged in a checkered manner or a method in which left-eye image frames and right-eye image frames are arranged alternately in a time-divisional manner. 
     On the other hand, if the signal judging section  201  judges that the input video signal is of 2D video, the left/right image separating section  221  does not separate the input 2D video signal because it does not contain a left-eye video signal and a right-eye video signal. Instead, the left/right image separating section  221  extracts 2D image frames from the input video signal and outputs them to each of the blending sections  222  and  223 . 
     If the signal judging section  201  judges that the input video signal is of 3D video, the blending section  222  generates new left-eye image frames by combining (superimposing) the left-eye OSD image signal that is input from the left-eye OSD buffer  212  via the selector  214  with (on) the left-eye video signal that is input from the left/right image separating section  221  and outputs the generated left-eye image frames to the frame rate converting section  224 . The blending section  223  generates new right-eye image frames by combining (superimposing) the right-eye OSD image signal that is input from the right-eye OSD buffer  213  with (on) the right-eye video signal that is input from the left/right image separating section  221  and outputs the generated right-eye image frames to the frame rate converting section  224 . 
     If the signal judging section  201  judges that the input video signal is of 2D video, the blending section  222  generates new 2D image frames by combining (superimposing) the 2D OSD image signal that is input from the right-eye OSD buffer  213  via the selector  214  with (on) the 2D image frames that are input from the left/right image separating section  221  and outputs the generated 2D image frames to the frame rate converting section  224 . The blending section  223  generates new 2D image frames by combining (superimposing) the 2D OSD image signal that is input from the right-eye OSD buffer  213  with (on) the 2D image frames that are input from the left/right image separating section  221  and outputs the generated 2D image frames to the frame rate converting section  224 . 
     That is, the blending section  222  and the blending section  223  operate in a similar manner for both the 3D video and the 2D video. 
     If the signal judging section  201  judges that the input video signal is of 3D video, the frame rate converting section  224  generates a left-eye image frame group from the left-eye image frames input from the blending section  222  by adding (a prescribed number of) interpolation frames. Likewise, the frame rate converting section  224  generates a right-eye image frame group from the right-eye image frames input from the blending section  223  by adding interpolation frames. 
     The left-eye image frame group and the right-eye image frame group generated by adding the interpolation frames have more image frames than the left-eye image frames that are input from the blending section  222  and the right-eye image frames that are input from the, blending section  223 , respectively. That is, the frame rate converting section  224  performs conversions so that the frame interval is shortened (i.e., the frame rate is increased). The frame rate converting section  224  outputs the image frames of the generated left-eye image frame group and right-eye image frame group to the display unit  61  in prescribed order and causes the display unit  61  to display them. 
     On the other hand, if the signal judging section  201  judges that the input video signal is of 2D video, the frame rate converting section  224  selects one of the two image frames that are input from the respective blending sections  222  and  223  and adds (a prescribed number of) interpolation frames based on the selected image frame. The frame rate converting section  224  thus generates a frame-interpolated 2D image frame group. The frame rate converting section  224  outputs the generated 2D image frames to the display unit  61  in prescribed order and causes the display unit  61  to display them. 
     If the signal judging section  201  judges that the input video signal is of 3D video, the display disabling section  231  turns off the backlight  102  with prescribed timing to not display a corresponding image frame on the display unit  61 , or send a non-display video signal to the liquid crystal panel  101  with prescribed timing so that display is not made on the display unit  61 . If the signal judging section  201  judges that the input video signal is of 2D video, basically, the display disabling section  231  controls the display unit  61  so as to enable display of an image frame. However, the display disabling section  231  may control the display unit  61  so as to disable display with prescribed timing to prevent a so-called motion blur. 
     If the signal judging section  201  judges that the input video signal is of 3D video, the shutter control section  81  outputs, to the 3D glasses EG, shutter control signals for opening the left-eye shutter and the right-eye shutter of the 3D glasses EG alternately in synchronism with the output of the left-eye and right-eye image frames from the frame rate converting section  224 . If the signal judging section  201  judges that the input video signal is of 2D video, the shutter control section  81  outputs, to the 3D glasses EG, shutter control signals for opening the left-eye shutter and the right-eye shutter of the 3D glasses EG all the time. 
     Most of the blocks shown in  FIG. 2  need to operate in synchronism with each other according to a prescribed timing scheme so that as described above the shutter control section outputs shutter control signals for opening/closing the shutters with the same timing as the frame rate converting section  224  outputs image frames. In the first embodiment, it is preferable that the individual blocks shown in  FIG. 2  operate in synchronism with each other according to a prescribed timing scheme being controlled by a prescribed sync signal which is managed by the shutter control section  81  based on a timing scheme according which the left/right image separating section  221  outputs image frames. Instead of the shutter control section  81 , another block may manage the prescribed sync signal. 
     In the system configuration of  FIG. 2 , the “left” and the “right” may be interchanged. More specifically, where an input video signal is of 3D video, opposite OSD image signals (i.e., opposite to the OSD image signals in the system configuration of  FIG. 2 ) may be stored in the (right-eye) OSD buffer  212  and the (left-eye) OSD buffer  213 . The left/right image separating section  221  may output opposite video signals to the blending sections  222  and  223 , and the frame rate converting section  224  may receive opposite sets of image frames from the blending sections  222  and  223 . The “left” and the “right” can be also interchanged for the other blocks. 
     The system configuration of  FIG. 2  may be modified so that the left/right image separating section  221  outputs an input 2D video signal to one of the blending sections  222  and  223  if the signal judging section  201  judges that the input video signal is of 2D video. In this configuration, the frame rate converting section  224  selects a signal that is input from the one of the blending sections  222  and  223  that receives the input 2D video signal. The other of the blending sections  222  and  223  need not receive the OSD image signal or output the OSD image signal even if it is received. 
     The selector  214  may be provided between the right-eye OSD buffer  213  and the blending section  223  rather than between the left-eye OSD buffer  212  and the blending section  222 . 
     With the above example system configuration, the signal processing control section  40  performs processing of superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal and processing of controlling the 3D glasses EG. 
     Next, a process which is executed by the above-described blocks to superimpose a 3D or 2D OSD image signal on an input video signal and display a resulting signal will be described with reference to  FIG. 3 . 
       FIG. 3  illustrates the example process for superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal. 
     First, at step S 301 , the signal judging section  210  judges whether an input video signal is of 3D video or 2D video. If the signal judging section  201  judges that the input video signal is of 3D video (S 301 : yes), at step S 302  the OSD signal generating section  211  generates a left-eye OSD image signal and a right-eye OSD image signal and outputs them to the left-eye OSD buffer  212  and the right-eye OSD buffer  213 , respectively. 
     At step S 303 , the, left/right image separating section  221  extracts (separates) a left-eye video signal and a right-eye video signal from the image frames of the input 3D video signal and outputs the extracted signals to the respective blending sections  222  and  223 . 
     At step S 304 , the blending section  222  generates new left-eye image frames by combining (superimposing) the left-eye OSD image signal that is input from the left-eye OSD buffer  212  via the selector  214  with (on) the extracted left-eye video signal according to a prescribed timing scheme and outputs the generated left-eye image frames to the frame rate converting section  224 . The blending section  223  generates new right-eye image frames by combining (superimposing) the right-eye OSD image signal that is input from the right-eye OSD buffer  213  with (on) the separated right-eye video signal according to a prescribed timing scheme and outputs the generated right-eye image frames to the frame rate converting section  224 . The selector  214  is set to output the left-eye OSD image signal to the blending section  222 . 
     At step S 305 , the frame rate converting section  224  alternately arrange the image frames of left-eye image frame group generated based on the left-eye image frames received from the blending section  222  and the image frames of right-eye image frame group generated based on the right-eye image frames received from the blending section  223 , and outputs resulting image frames to the display unit  61  in prescribed order to cause the display unit  61  to display those image frames. 
     On the other hand, if the signal judging section  201  judges that the input video signal is of 2D video (S 301 : no), at step S 306  the OSD image generating section  211  generates a 2D OSD image signal and outputs it to the right-eye OSG buffer  213 . At step S 307 , the left/right image separating section  221  does not separate the input video signal and outputs its 2D image frames to each of the blending sections  222  and  223 . 
     At step S 308 , the blending section  222  generates new 2D image frames by combining (superimposing) the 2D OSD image signal that is input from the right-eye OSD buffer  213  via the selector  214  with (on) the input video signal that is input from the left/right image separating section  221  according to a prescribed timing scheme and outputs the generated 2D image frames to the frame rate converting section  224 . The blending section  223  generates new 2D image frames by combining (superimposing) the 2D OSD image signal that is input from the right-eye OSD buffer  213  with (on) the input video signal that is input from the left/right image separating section  221  according to a prescribed timing scheme and outputs the generated 2D image frames to the frame rate converting section  224 . The selector  214  is set to output the right-eye OSD image signal to the blending section  222 . 
     At step S 309 , the frame rate converting section  224  outputs the image frames of 2D image frame groups generated based on one of the two sets of image frames that are input from the blending sections  222  and  223  to the display unit  61  in prescribed order to cause the display unit  61  to display those image frames. 
     In the above-described manner, the blocks provided in the signal processing control section  40  etc. according to the first embodiment generate an OSD image signal corresponding to an input video signal depending on whether the input video signal is of 3D video or 2D video, superimposes the generated 3D or 2D OSD image signal on the input video signal, and displays a resulting signal. 
     Next, a process for displaying input 3D video, which is to be executed by the above-described blocks as a base of the process for superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal, will be described with reference to  FIGS. 4-8 . 
     First, specific examples of a 3D video signal which is input to the signal judging section  201  and the left/right image separating section  221  will be described with reference to  FIGS. 4 and 5 .  FIGS. 4 and 5  show specific examples of a 3D video signal. 
     More specifically, an image frame V 1  of a 3D video signal shown in  FIG. 4  is such that a left-eye video signal and a right-eye video signal are multiplexed together according to an encoding method of alternately arranging scanning line portions of a left-eye video signal L and scanning line portions of a right-eye video signal R. The left/right image separating section  221  separates the input image frame V 1  into two image frames by extracting, from the input image frame V 1 , a left-eye image frame L 1  obtained by converting the left-eye video signal L into a non-interlaced signal and a right-eye image frame R 1  obtained by converting the right-eye video signal R into a non-interlaced signal. 
     An image frame V 2  (V 3 ) of a 3D video signal shown in  FIG. 5  is such that a left-eye video signal and a right-eye video signal are multiplexed together according to an encoding method of arranging a left-eye video signal L and a right-eye video signal R in a left-hand area and a right-hand area, respectively, of one image frame. The left/right image separating section  221  separates the input image frame V 2  (V 3 ) into two image frames by extracting, from the input image frame V 2  (V 3 ), a left-eye image frame L 2  (L 3 ) obtained by expanding the left-eye video signal L in the horizontal direction by a factor of two and a right-eye image frame R 2  (R 3 ) obtained by expanding the right-eye video signal R in the horizontal direction by a factor of two. 
     If a left-eye video signal and a right-eye video signal are multiplexed together according to an encoding method of arranging square areas each having a prescribed number of pixels in checkered manner (not shown), a left-eye image frame and a right-eye image frame are extracted by processing that is similar to the processing for the 3D video signal shown in  FIG. 5 . 
     In the case of such an encoding method as a method of arranging left-eye image frames and right-eye image frames alternately in a time-divisional manner (not shown), both of a left-eye image frame and a right-eye image frame are not extracted from one image frame. Instead, a left-eye image frame and a right-eye image frame are extracted from each set of image frames. 
     Information relating to a 3D video signal encoding method such as the encoding method of  FIG. 4  or  5  is contained in information relating to a connection authentication that is performed with an external apparatus that complies with the HDMI standard or information relating to coding of an input video signal. The signal judging section  201  can judge whether an input video signal is of 3D video or not using such information. 
     Next, specific examples of a set of image frames that are generated from a 3D video signal that is input to the signal judging section  201  and the left/right image separating section  221  (described above with reference to  FIG. 2 ) through frame rate conversion and image frame rearrangement and are to be output to the display unit  61  will be described with reference to  FIGS. 6 and 7 . 
       FIGS. 6 and 7  illustrate specific examples of a set of image frames that are generated from an input 3D video signal through frame rate conversion and image frame rearrangement and are to be output to the display unit  61 . 
     More specifically,  FIG. 6  shows a specific example of image frame groups that are generated from the 3D video signal of  FIG. 5  and are to be output to the display unit  61 . Image frames V 2  and V 3  in each of which a left-eye video signal L and a right-eye video signal R are multiplexed together as shown in  FIG. 6  are input at frame intervals of 1/60 s (frame rate: 60 f/s). 
     A left-eye image frame L 2  and a right-eye image frame R 2  that are extracted (separated) from the image frame V 2  are subjected to prescribed processing in the respective blending sections  222  and  223  and input to the frame rate conversion section  224 . The frame rate conversion section  224  generates an image frame L 2   a  (interpolation frame) based on the received left-eye image frame L 2  and thereby generates a left-eye image frame group L 2   grp  including the image frames L 2  and L 2   a . Likewise, the frame rate conversion section  224  generates an image frame R 2   a  (interpolation frame) based on the received right-eye image frame R 2  and thereby generates a right-eye image frame group R 2   grp  including the image frames R 2  and R 2   a.    
     Although in the above example one left-eye interpolation frame and one right-eye interpolation frame are generated, more interpolation frames may be generated, that is, the number of generated interpolation frames is not limited to any number. An interpolation frame may be generated either by copying an original image frame or by interpolating a frame by performing prescribed processing also using an immediately preceding or following image frame for each of a left-eye and right-eye image frames. 
     The frame rate converting section  224  arranges the left-eye image frame group L 2   grp  and the right-eye image frame group R 2   grp  alternately in a time-divisional manner, and outputs their image frames sequentially to the display unit  61  to cause the display unit  61  to display them. 
     More specifically, the frame rate converting section  224  sequentially outputs the image frames L 2 , L 2   a , R 2 , and R 2   a  to the display unit  61  in this order. The same processing is performed on the image frame V 3 , whereby a left-eye image frame group L 3   grp  including image frames L 3  and L 3   a  and the right-eye image frame group R 3   grp  including image frames R 3  and R 3   a  are generated. The frame rate converting section  224  sequentially outputs the image frames L 3 , L 3   a , R 3 , and R 3   a  to the display unit  61  in this order. 
     As described above, the frame rate converting section  224  generates a group of two left-eye image frames and a group of two right-eye image frames from each image frame of an input 3D video signal, arranges the two kinds of groups alternately in a time-divisional manner, and outputs resulting image frames to the display unit  61  sequentially. As a result, the original frame interval 1/60 s is converted into a frame interval 1/240 s (frame rate: 240 f/s). 
     In a 3D video signal shown in  FIG. 7 , left-eye image frames V 21  and V 23  (left-eye image signal) and right-eye image frames V 22  and V 24  (right-eye image signal) are input alternately at frame intervals of 1/120 s (frame rate: 120 f/s). 
     When the above 3D video signal is input, the frame rate converting section  224  generates, from the received left-eye image frame V 21 , a left-eye image frame group L 21   grp  including image frames L 21  (V 21 ) and L 21   a , and generates, from the received right-eye image frame V 22 , a right-eye image frame group R 22   grp  including image frames R 22  (V 22 ) and R 22   a . The frame rate converting section  224  outputs the image frames L 21 , L 21   a , R 22 , and R 22   a  to the display unit  61  in this order. The same processing is performed on the image frames V 23  and V 24 , whereby image frames L 23 , L 23   a , R 24 , and R 24   a  are output to the display unit  61  in this order. 
     As described above, in the case of the 3D video signal as shown in  FIG. 7  which has a frame interval of 1/120 s, the frame rate converting section  224  arranges two image frames for each of left-eye image frames and right-eye image frames that are received alternately and outputs resulting image frames sequentially to the display unit  61 . As a result, the original frame interval 1/120 s is converted into a frame interval 1/240 s. 
     Next, a timing scheme for the control of the output of a 3D video signal to the display unit  61  and the opening/closing of the shutters of the 3D glasses EG will be described with reference to  FIG. 8 . 
       FIG. 8  illustrates the example timing chart for the output control of a 3D video signal to the display unit  61  and the opening/closing control of the shutters of the 3D glasses EG. 
     As shown in  FIG. 8 , the image frames that are input from the frame rate converting section  224  are rewritten sequentially as the scanning lines of the display panel  101  are scanned downward. In synchronism with the image frame rewriting on the display panel  101 , the display disabling section  231  enable or disable the display and the shutter control section  81  controls the opening/closing of the shutters of the 3D glasses EG. As a result, the user of the TV receiver  10  can visually recognize 3D video displayed on the screen through the 3D glasses EG. 
     More specifically, in the scanning period of the left-eye image frame L 2 , the immediately preceding, right-eye frame image R is rewritten to the left-eye image frame L 2  and hence an image R+L 2  which is a mixture of the right-eye frame image R and the left-eye image frame L 2  is displayed. In this period, to disable display, the display disabling section  231  controls the backlight  102  so as to turn it off. The shutter control section  81  controls the shutters so as to close the left-eye shutter and open the right-eye shutter. Alternatively, the shutter control section  81  may control the shutters in an opposite manner so as to open the left-eye shutter and close the right-eye shutter or control the shutters so as to close both of the left-eye shutter and the right-eye shutter. 
     In the scanning period of the left-eye image frame L 2   a , the immediately preceding, left-eye frame image L 2  is rewritten to the left-eye image frame L 2   a  and hence an image L 2 +L 2   a  which is a mixture of the left-eye image frames L 2  and L 2   a  is displayed. In this period, to enable display, the display disabling section  231  controls the backlight  102  so as to turn it on. The shutter control section  81  controls the shutters so as to open the left-eye shutter and close the right-eye shutter. 
     In the scanning period of the right-eye image frame R 2 , the immediately preceding, left-eye frame image L 2   a  is rewritten to the right-eye image frame R 2  and hence an image L 2   a +R 2  which is a mixture of the left-eye frame image L 2   a  and the right-eye image frame R 2  is displayed. In this period, to disable display, the display disabling section  231  controls the backlight  102  so as to turn it off. The shutter control section  81  controls the shutters so as to open the left-eye shutter and close the right-eye shutter. Alternatively, the shutter control section  81  may control the shutters in an opposite manner so as to close the left-eye shutter and open the right-eye shutter or control the shutters so as to close both of the left-eye shutter and the right-eye shutter. 
     In the scanning period of the right-eye image frame R 2   a , the immediately preceding, right-eye frame image R 2  is rewritten to the right-eye image frame R 2   a  and hence an image R 2 +R 2   a  which is a mixture of the right-eye image frames R 2  and R 2   a  is displayed. In this period, to enable display, the display disabling section  231  controls the backlight  102  so as to turn it on. The shutter control section  81  controls the shutters so as to close the left-eye shutter and open the right-eye shutter. 
     As described above, the display disabling section  231  disables display during periods of rewriting from a left-eye image frame to a right-eye image frame or vice versa. On the other hand, the display disabling section  231  enables display during periods of rewriting from a left-eye (or right-eye) image frame to the next left-eye (or right-eye) image frame. And the shutter control section  81  controls the shutters so as to open the corresponding left-eye or right-eye shutter during periods when only left-eye or right-eye image frames are displayed on the screen (i.e., a left-eye image frame and a right-eye image frame are not displayed in mixture). This operation prevents display of video that is impaired in 3D sense. 
     (Modification) 
     Next, modified blocks which perform processing of superimposing a 3D or 2D OSD image signal on an input video signal depending on the type of the input video signal to display a resulting signal and processing of controlling the 3D glasses EG will be described with reference to  FIG. 9 . 
       FIG. 9  illustrates the example system block configuration according to a modification of the first embodiment for superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal and controlling the 3D glasses EG. 
     A signal processing control section  40  according to the modification of the first embodiment includes a signal judging section  201 , an OSD image generating section  911 , a left-eye OSD buffer  912 , a right-eye OSD buffer  913 , a left/right image separating section  221 , blending sections  922  and  223 , a frame rate converting section  224 , a display disabling section  231 , etc. 
     The system configuration of  FIG. 9  also provides a video combining device. The video combining device may be provided separately from the signal processing control section  40 . 
     Although the system according to the modification performs approximately the same processing as that of  FIG. 2 , the selector  214  is not provided and the left-eye OSD buffer  912  is directly connected to the blending section  922 . In operation, the OSD image generating section  911  outputs a prescribed OSD signal(s) to the left-eye OSD buffer  912  and the right-eye OSD buffer  913  depending on the judgment result of the signal judging section  201 . 
     Because of the above differences, the OSD image generating section  911 , the left-eye OSD buffer  912 , the right-eye OSD buffer  913 , and the blending section  922  operate differently than the OSD image generating section  211 , the left-eye OSD buffer  212 , the right-eye OSD buffer  213 , and the blending section  222  shown in  FIG. 2 . The other blocks operate in the same manners as the corresponding blocks shown in  FIG. 2 , and hence are given the same reference numerals as the latter and will not be described in detail. Therefore, in the following, the OSD image generating section  911 , the left-eye OSD buffer  912 , the right-eye OSD buffer  913 , and the blending section  922  will be described in detail. 
     If the signal judging section  201  judges that an input video signal is of 3D video, the OSD image generating section  911  generates a left-eye OSD image signal and a right-eye OSD image signal and outputs them to the left-eye OSD buffer  212  and the right-eye OSD buffer  213 , respectively. If the signal judging section  201  judges that the input video signal is of 2D video, the OSD image generating section  911  generates a 2D OSD image signal and outputs it to the left-eye OSD buffer  912  and the right-eye OSD buffer  913 . 
     The left-eye OSD buffer  912  stores the left-eye OSD image signal corresponding to the 3D video or the 2D OSD image signal corresponding to the 2D video that is input from the OSD image generating section  911 , and outputs it to the blending section  922  with prescribed timing. 
     The right-eye OSD buffer  913  stores the right-eye OSD image signal corresponding to the 3D video or the 2D OSD image signal corresponding to the 2D video that is input from the. OSD image generating section  911 , and outputs it to the blending section  923  with prescribed timing. 
     If the signal judging section  201  judges that the input video signal is of 3D video, the blending section  922  generates new left-eye image frames by combining (superimposing) the left-eye OSD image signal that is input from the left-eye OSD buffer  912  with (on) a left-eye video signal that is input from the left/right image separating section  221  and outputs the generated left-eye image frames to the frame rate converting section  224 . If the signal judging section  201  judges that the input video signal is of 2D video, the blending section  922  generates new 2D image frames by combining (superimposing) the 2D OSD image signal that is input from the left-eye OSD buffer  912  with (on) the 2D image signal that is input from the left/right image separating section  221  and outputs the generated 2D image frames to the frame rate converting section  224 . 
     In the system configuration of  FIG. 9 , the “left” and the “right” may be interchanged. More specifically, where an input video signal is of 3D video, opposite OSD image signals (i.e., opposite to the OSD image signals in the system configuration of  FIG. 9 ) are stored in the (right-eye) OSD buffer  912  and the (left-eye) OSD buffer  913 . The left/right image separating section  221  outputs opposite video signals to the blending sections  922  and  223 , and the frame rate converting section  224  receives opposite sets of image frames from the blending sections  922  and  223 . The “left” and the “right” can be also interchanged for the other blocks. 
     The system configuration of  FIG. 9  may be modified so that the left/right image separating section  221  outputs the input 2D video signal to one of the blending sections  922  and  223  if the signal judging section  201  judges that the input video signal is of 2D video. In this configuration, the frame rate converting section  224  selects a signal that is input from the one of the blending sections  922  and  223  that receives the input 2D video signal. The other of the blending sections  922  and  223  need not receive the OSD image signal or output the OSD image signal even if it is received. The left-eye OSD buffer  912  or the right-eye OSD buffer  913  that corresponds to the other of the blending sections  922  and  223  need not store the OSD image signal. 
     With the above example system configuration, as the first embodiment, the signal processing control section  40  performs processing of superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal and processing of controlling the 3D glasses EG. 
     As described above, in the first embodiment, in the process for superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal, a 3D or 2D OSD image signal is generated according to the type of an input video signal. A 3D OSD image signal is superimposed on a 3D video signal and a 2D OSD image signal is superimposed on a 2D image signal. Image frame groups each consisting of a prescribed number of image frames are generated from image frames in which OSD images corresponding to the input video signal are incorporated, and displayed on the display unit  61  in prescribed order. The opening/closing of the shutters of the 3D glasses EG is also controlled in a manner depending on the type of the input video signal. 
     Second Embodiment 
     Next, a system configuration according to a second embodiment for superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal will be described with reference to  FIG. 10 . 
       FIG. 10  illustrates the example system block configuration according to the second embodiment for superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal and controlling the 3D glasses EG. 
     A signal processing control section  40  according to the second embodiment includes a signal judging section  201 , an OSD image generating section  911 , a left-eye OSD buffer  1012 , a right-eye OSD buffer  1013 , a selector  1014 , a left/right image separating section  1021 , a frame transfer processing section  1022 , a blending sections  1023 , a frame rate converting section  1024 , a display disabling section  231 , etc. 
     The system configuration of  FIG. 10  also provides a video combining device. The video combining device may be provided separately from the signal processing control section  40 . 
     Although the system according to the embodiment operates approximately in the same manner as the systems according to the first embodiment and its modification, several blocks having corresponding blocks in  FIG. 2  or  9  operate differently than the latter. Therefore, in the following, the blocks that operate differently than the corresponding blocks in  FIG. 2  or  9  will mainly be described in detail. The other blocks that operate in the same manners as the corresponding blocks in  FIG. 2  or  9  will not be described in detail. 
     The signal judging section  201  and the OSD generating section  911  operate in the same manners as the signal judging section  201  shown in  FIG. 2  and the OSD generating section  911  shown in  FIG. 9 , respectively, and hence will not be described in detail. 
     The left-eye OSD buffer  1012  stores a left-eye OSD image signal corresponding to the 3D video that is input from the OSD generating section  911  or a 2D OSD image signal corresponding to the 2D video, and outputs the stored OSD image signal to the selector  1014  with prescribed timing., 
     The right-eye OSD buffer  1013  stores a right-eye OSD image signal corresponding to the 3D video that is input from the OSD generating section  911  or the 2D OSD image signal corresponding to the 2D video, and outputs the stored. OSD image signal to the selector  1014  with prescribed timing. 
     If the signal judging section  201  judges that an input video signal is of 3D video, the selector  1014  switches between the left-eye OSD image signal that is input from the left-eye OSD buffer  1012  and the right-eye OSD image signal that is input from the right-eye OSD buffer  1013  with a prescribed timing scheme and outputs the thus-selected OSD image signal to the blending section  1023  on a frame-by-frame basis. 
     On the other hand, if the signal judging section  201  judges that an input video signal is of 2D video, the selector  1014  switches between the 2D OSD image signal that is input from the left-eye OSD buffer  1012  and the 2D OSD image signal that is input from the right-eye OSD buffer  1013  with a prescribed timing scheme and outputs the thus-selected OSD image signal to the blending section  1023  on a frame-by-frame basis. 
     If the signal judging section  201  judges that an input video signal is of 3D video, the left/right image separating section  1021  separates the input 3D video signal into two sets of image frames by extracting a left-eye video signal (left-eye image frames) and a right-eye video signal (right-eye image frames) from image frames of the input 3D video signal by performing prescribed processing on a frame-by-frame basis and outputs the two sets of image frames to the frame transfer processing section  1022 . If the signal judging section  201  judges that an input video signal is of 2D video, the left/right image separating section  1021  does not separate the input 2D video signal because it does not contain a left-eye video signal and a right-eye video signal. Instead, the left/right image separating section  1021  extracts 2D image frames from the input video signal and outputs them to the frame transfer processing section  1022 . 
     If the signal judging section  201  judges that an input video signal is of 3D video, the frame transfer processing section  1022  transfers (outputs), to the blending section  1023 , the left-eye image frames and the right-eye image frames that are input from the left/right image separating section  1021  after arranging them alternately in a time-divisional manner. On the other hand, if the signal judging section  201  judges that an input video signal is of 2D video, the frame transfer processing section  1022  transfers (outputs) the received video signal (2D image frames) to the blending section  1023 . 
     If the signal judging section  201  judges that an input video signal is of 3D video, the blending section  1023  generates new left-eye and right-eye image frames by combining (superimposing) the image frames that are input form the frame transfer processing section  1022  and in which the left-eye image frames and the right-eye image frames are arranged alternately with (on) the left-eye OSD image frames and the right eye OSD image frames that are input from the selector  1014  in synchronism with the image frames that are output from the frame transfer processing section  1022  and outputs the generated left-eye and right-eye image frames to the frame rate converting section  1024 . On the other hand, if the signal judging section  201  judges that an input video signal is of 2D video, the blending section  1023  generates new 2D image frames by combining (superimposing) the 2D image frames that are input from the frame transfer processing section  1022  with (on) the 2D OSD image signals that are input from the selector  1014  in synchronism with the image frames that are output from the frame transfer processing section  1022  and outputs the generated 2D image frames to the frame rate converting section  1024 . 
     That is, the blending section  1023  operates in a similar manner for both the 3D video and the 2D video. 
     If the signal judging section  201  judges that the input video signal is of 3D video, the frame rate converting section  1024  adds interpolation frames (a prescribed number of image frames) based on each of the left-eye and right-eye image frames that are input from the blending section  1023 . The frame rate converting section  1024  generates a frame-interpolated left-eye image frame group and a frame-interpolated right-eye image frame group. The frame rate converting section  1024  outputs the image frames of the generated left-eye image frame group and right-eye image frame group to the display unit  61  in prescribed order and causes the display unit  61  to display them. 
     On the other hand, if the signal judging section  201  judges that the input video signal is of 2D video, the frame rate converting section  1024  adds interpolation frames (a prescribed number of image frames) based on each image frame that is input from the blending section  1023 . The frame rate converting section  1024  thus generates a frame-interpolated 2D image frame group. The frame rate converting section  1024  outputs the generated 2D image frames to the display unit  61  in prescribed order and causes the display unit  61  to display them. 
     The display disabling section  231  operates in the same manner as that shown in  FIG. 2  and hence will not be described in detail. 
     If the signal judging section  201  judges that the input video signal is of 3D video, the shutter control section  81  outputs, to the 3D glasses EG, shutter control signals for opening the left-eye shutter and the right-eye shutter of the 3D glasses EG alternately in synchronism with the output of the left-eye and right-eye image frames from the frame rate converting section  1024 . If the signal judging section  201  judges that the input video signal is of 2D video, the shutter control section  81  outputs, to the 3D glasses EG, shutter control signals for opening the left-eye shutter and the right-eye shutter of the 3D glasses EG all the time. 
     Most of the blocks shown in  FIG. 10  need to operate in synchronism with each other according to a prescribed timing scheme so that as described above the shutter control section  81  outputs shutter control signals for opening/closing the shutters with the same timing as the frame rate converting section  1024  outputs image frames. In the second embodiment, it is preferable that the individual blocks shown in  FIG. 10  operate in synchronism with each other according to a prescribed timing scheme being controlled by a prescribed sync signal which is managed by the shutter control section  81  based on a timing scheme according which the left/right image separating section  221  outputs image frames. Instead of the shutter control section  81 , another block may manage the prescribed sync signal. 
     In the system configuration of  FIG. 10 , the “left” and the “right” may be interchanged. More specifically, where an input video signal is of 3D video, opposite OSD image signals (i.e., opposite to the OSD image signals in the system configuration of  FIG. 10 ) are stored in the (right-eye) OSD buffer  1012  and the (left-eye) OSD buffer  1013 . The left/right image separating section  1021  outputs opposite video signals to the frame transfer processing section  1022 . The “left” and the “right” can be also interchanged for the other blocks. 
     The system configuration of  FIG. 10  may be modified so that the OSD generating section outputs an input 2D video signal to one of the left-eye OSD buffer  1012  and the right-eye OSD buffer  1013  if the signal judging section  201  judges that the input video signal is of 2D video. In this configuration, the selector  1014  is set to select a signal that is input from the one of the left-eye OSD buffer  1012  and the right-eye OSD buffer  1013  that receives the input 2D video signal. The other of the left-eye OSD buffer  1012  and the right-eye OSD buffer  1013  receives no input signal from the OSD image generating section  911  and hence stores nothing. 
     With the above example system configuration, the signal processing control section  40  performs processing of superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal and processing of controlling the 3D glasses EG. 
     As described above, also in the second embodiment, in the process for superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal, a 3D OSD image signal is superimposed on an input 3D video signal and a 2D OSD image signal is superimposed on an input 2D image signal. Image frame groups each consisting of a prescribed number of image frames are generated from image frames in which OSD images corresponding to the input video signal are incorporated, and displayed on the display unit  61  in prescribed order. The opening/closing of the shutters of the 3D glasses EG is also controlled in a manner depending on the type of the input video signal. 
     Next, a process which is executed by the above-described blocks to superimpose a 3D or 2D OSD image signal on an input video signal and display a resulting signal will be described with reference to  FIG. 11 . 
       FIG. 11  illustrates the example process for superimposing a 3D or 2D OSD image signal on an input video signal to display a resulting signal. 
     First, at step S 1101 , the signal judging section  210  judges whether an input video signal is of 3D video or 2D video. If the signal judging section  201  judges that the input video signal is of 3D video (S 1101 : yes), at step S 1102  the OSD signal generating section  211  generates a left-eye OSD image signal and a right-eye OSD image signal and outputs them to the left-eye OSD buffer  1012  and the right-eye OSD buffer  1013 , respectively. 
     At step S 1103 , the left/right image separating section  1021  extracts (separates) a left-eye video signal(left-eye image frames) and a right-eye video signal (right-eye image frames) from image frames of the input 3D video signal and outputs the extracted signals to the frame transfer processing section  1022 . The frame transfer processing section  1022  transfers (outputs), to the blending section  1023 , the received left-eye and right-eye image frames after arranging them alternately in a time-divisional manner. 
     At step S 1104 , the blending section  1023  generates new left-eye and right-eye image frames by combining (superimposing) the received left-eye and right-eye image frames with (on) the left-eye and right eye OSD image frames that are input from the selector  1014  in synchronism with the image frames that are output from the frame transfer processing section  1022  and outputs the generated left-eye and right-eye image frames to the frame rate converting section  1024 . That is, the selector  1014  outputs the left-eye OSD image signal that is input from the left-eye OSD buffer  1012  and the right-eye OSD image signal that is input from the right-eye OSD buffer  1013  to the blending section  1023  in a switched manner on a frame-by-frame basis in synchronism with the output of the left-eye and right-eye image frames from the frame transfer processing section  1022 . 
     At step S 1105 , the frame rate converting section  1024  output the image frames of left-eye image frame group and right-eye image frame group generated based on the received left-eye and right eye image frames to the display unit  61  in prescribed order to cause the display unit  61  to display those image frames. 
     On the other hand, if the signal judging section  201  judges that the input video signal is of 2D video (S 1101 : no), at step S 1106  the OSD image generating section  911  generates a 2D OSD image signal and outputs it to the left-eye OSD buffer  1012  and the right-eye OSG buffer  1013 . At step S 1107 , the left/right image separating section  1021  does not separate the input video signal and outputs its 2D image frames to the frame transfer processing section  1022 . The frame transfer processing section  1022  transfers (outputs) the received video signal to the blending section  1023 . 
     At step S 1108 , the blending section  1023  generates new 2D image frames by combining (superimposing) the input video signal that is input from the frame transfer processing section  1022  with (on) the 2D OSD image signal that is input from the selector  1014  in synchronism with the input video signal, and outputs the generated 2D image frames to the frame rate converting section  1024 . The selector  1014  outputs the 2D OSD image signal that is input from the left-eye OSD buffer  1013  and the 2D OSD image signal that is input from the right-eye OSD buffer  1013  to the blending section  222  in a switched manner on a frame-by-frame basis in synchronism with the output of the 2D image frames from the frame transfer processing section  1022 . 
     At step S 1109 , the frame rate converting section  1024  outputs the image frames of 2D image frame groups generated based on the image frames that are input from the blending sections  1023  to the display unit  61  in prescribed order to cause the display unit  61  to display those image frames. 
     In the above-described manner, the blocks provided in the signal processing control section  40  etc. according to the second embodiment generate an OSD image signal corresponding to an input video signal depending on whether the input video signal is of 3D video or 2D video, superimposes the generated 3D or 2D OSD image signal on the input video signal, and displays a resulting signal. 
     As described above, in the second embodiment, whether an input video signal is of 3D video or 2D video is judged. If the input video signal is of 3D video, a left-eye OSD image signal and a right-eye OSD image signal that are generated individually are synchronized and combined with a left-eye video signal and a right-eye video signal, respectively, that are separated from the input video signal, whereby an arrangement of image frames is generated. The image frames of the arrangement are output sequentially in prescribed order. If the input video signal is of 2D video, a generated 2D OSD image signal is synchronized and combined with the input video signal, whereby an arrangement of image frames is generated. The image frames of the arrangement are output sequentially in prescribed order. That is, an input video signal can be processed in the same manner irrespective of whether it is of 3D video or 2D video. As such, according to the second embodiment of the invention, video generated by combining a 3D or 2D graphic object with an input video signal depending on the type of the input video signal can be displayed. 
     The embodiments are not limited to the above configurations, and various changes, modifications, etc. are possible without departing from the spirit and scope of the invention. 
     According to an aspect of the present invention, there is provided a video combining device, a video display apparatus, and a video combining method which make it possible to display video obtained by combining a graphic object of 3D or 2D with an input video signal depending on the type of the input video signal.