Abstract:
An apparatus for implementing stereoscopic images without control programs on a CRT monitor in a computer system includes a video adapter storing the information of stereoscopic images reading out the contents of the information, and outputting them as analog image signals of red, green and blue colors, vertical synchronizing signals and horizontal synchronizing signal, an analog scan line controller operating in response to external on/off control signals, and outputting the analog image signals including left eye image information and right eye image information to the monitor in response to the vertical synchronizing signals from the video adapter, and a shuttering device being operated by at least any one of the signals from the video adapter.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an apparatus for implementing stereoscopic images in a computer system, and more particularly to an apparatus for implementing stereoscopic images that have a scan line controller positioned between a VGA(Video Graphic Adapter) card and a CRT(Cathode Ray Tube) monitor in the computer system. 
     2. Description of Prior Art 
     In general, a technical principle for implementing stereoscopic images is that a person perceives a cubic effect by providing images in different visual angles for left eye and right eye. Each of the stereoscopic images consists of an image(left eye image) photographed in left eye side and an image(right eye image) photographed in right eye side. 
     Up to now, such a technique implementing the stereoscopic images is achieved by combining left eye image with the right eye image, and displaying the combined images on a CRT monitor. As typical method displaying the stereoscopic images on the monitor, there is an interlaced scan method that the left eye images and/or the right eye images are alternately displayed on even scan lines or odd scan lines of each field on the CRT monitor. 
     In the case of displaying the stereoscopic images on the CRT monitor according to the interlaced scan method, it is necessary for embedding a control program in a computer program to implement the stereoscopic images. The control program controls the computer VGA card and displays the stereoscopic images combined with the left eye image and the right eye image on the CRT monitor. 
     However, the interlaced scan method requires individual control programs corresponding to the types of VGA cards or the resolution mode of each VGA card because the property for each VGA card and the resolution of each VGA card are different. Also, it is necessary for much times and efforts to develops the control programs. It is substantially impossible to develops the control programs corresponding to all types of VGA cards. 
     Moreover, even though the control programs corresponding to all types of VGA cards have been developed, they should be revised according to the computer type because the control programs are not compatible in the different computer types. Also, in the case that user executes the control program in his(or hers) computer system, the user should change the settings of the VGA card according to the individual resolution mode. 
     In the recent, there is a tendency to do not use the interlaced scan method in the manufacture of the VGA card due to a flicker phenomenon which is generated when the properties(e.g. refresh rate of screen etc.) of the CRT monitor are not appropriate. Accordingly, it becomes more and more difficult to implement the stereoscopic images on the CRT monitor using the control programs. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, and object of the present invention is to easily implement stereoscopic images on a CRT monitor by positioning a scan line controller between the output of a computer graphic board and an input of the monitor without using the complicated control programs. 
     To achieve the above object, the present invention provides an apparatus for implementing stereoscopic images in a computer system comprising a video adapter storing the information of stereoscopic images consisted of left eye images and right eye images and the information of characters, reading out the contents of the information, and outputting them as analog image signals of red, green and blue colors, vertical synchronizing signals and horizontal synchronizing signals, and a monitor displaying the information of stereoscopic images and the information of characters, said apparatus comprising; 
     a scan line controller being operated in respond to an external on/off control signals, and outputting said analog image signals including left eye image information and right eye image information to the monitor in respond to said vertical synchronizing signal from said video adapter, in order to display the left eye image information or the right eye image information on odd scan lines or even scan lines of the monitor; 
     a shuttering means being operated by at least any one of signals from said video adapter, shuttering the left eye image information displayed on the odd scan lines or even scan lines to prevent them having been perceived a right eye, and shuttering the right eye image information displayed on the odd scan lines or even scan lines to prevent them having been perceived a left eye. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above object, and other features and advantages of the present invention will become more apparent by describing in detail preferred embodiment thereof with reference to the attached drawings, in which; 
     FIG. 1 is a schematic block diagram of an apparatus for implementing stereoscopic images in a computer system having a CRT monitor according to an embodiment of the present invention. 
     FIG. 2 is a detailed block diagram of principal parts FIG.  1 . 
     FIG. 3 is waveform views showing signals output from principal parts shown in FIG.  2 . 
     FIG. 4 is a circuit view showing the analog switch shown in FIG.  2 . 
     FIG. 5 is a circuit view showing the phase switch of stereoscopic images shown in FIG.  2 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Hereinafter, an apparatus for implementing stereoscopic images in a computer system according to an embodiment of the present invention will be described with reference to the accompanying drawings. 
     Referring to FIG. 1., reference numeral  10  denotes multipower dividing the first voltage V 1  supplied from an external electric source or a power supply in the computer system into two voltages V 2  and V 3 , and supplying to the apparatus for implementing stereoscopic images in the computer system according to the present invention, reference numeral  20  denotes VGA card storing the information to be displayed on the monitor, reading out the contents of the information, and converting them to control signals of the monitor, reference numeral  30  denotes a scan line controller outputting left eye image signals or right eye image signals of stereoscopic image signals to the monitor in respond to the vertical synchronizing signals from the VGA card to display the left eye images or right eye images to display on odd scan lines or even scan lines of the monitor, reference numeral  40  denotes a scan line mode switch controlling the scan line controller  30  in on/off mode by a handling of the user or a programmed key input, reference numeral  50  denotes a CRT monitor, reference numeral  60  denotes an image input signal sensor detecting the input image signals from the VGA card  20 , reference numeral  70  denotes a shutter driving part outputting the shutter driving signal in respond to the image signals detected by the sensor  60  and the control signals from the scan line controller  30 , reference numeral  80  denotes a left eye shutter perceiving the left eye image displayed on the monitor  50 , and reference numeral  90  denotes a right eye shutter perceiving the right eye image displayed on the monitor  50 , said shutters  80  and  90  may be glasses type or safety goggles type. 
     Referring to the FIG. 2, there is a detailed circuit block diagram of the scan line controller  30  and the shutter driving part  70  shown in FIG.  1 . In FIG. 2, the scan line controller  30  comprises a synchronizing signal buffer  32 , a vertical ½ divider  33 , a sensor  34  detecting a vertical blanking signal, a horizontal ½ divider  35 , and a control logic circuit  36 . The shutter driving part  70  comprises a 3-states buffer  71 , a left eye shutter driver  72 , a right eye shutter driver  73  and a phase switch  74  switching the left or right stereoscopic images. 
     The operation of the apparatus according to the present invention will hereinafter be described with reference to the FIGS. 1 and 3. 
     Referring to FIG. 1., the first voltage V 1  applied to multipower  10  may be a commercial voltage level in an external type or a computer internal voltage level supplied from the computer power supply in an built-in type. When the first voltage V 1  is applied to the multipower  10 , the multipower  10  divides the first voltage V 1  into the second voltage V 2 , e.g., 5 V and the third voltage V 3 , e.g., 9˜12 V. The second voltage V 2  is applied to the scan line controller  30 , the sensor  60 , and 3-states buffer  71 (Fig,  2 ) of the shutter driving part  70  respectively, and the third voltage V 3  is applied to shutter drivers  72  and  73 (FIG. 2) of the shutter driving part  70 . 
     The VGA card  20  processing the information to be displayed on the monitor  50  outputs analog image signals R, G and B representing red, green and blue colors respectively, a vertical synchronizing signal V_Sync, and a horizontal synchronizing signal H_Sync to the scan line controller  30 . 
     The sensor  60  outputs a control signal in respond to any one of the signals output from the VGA card  20  to control the operation of the shutter driving part  70 . In FIG. 1, the vertical synchronizing signal V_Sync and the horizontal synchronous signal H_Sync is shown as input signals of the sensor  60 . However input signals of the sensor  60  are not restricted to the above signals, it is possible to use any one of signals output from the VGA card  20 . A, B and C in FIG. 3 show the waveforms of the signals output from the VGA card  20 . 
     The scan line controller  30  outputs the signals R, G, B, V_Sync and H_Sync from the VGA card  20  to the monitor  50  in respond to the control signal(on control signal or off control signal) from the scan line mode switch  40 , and outputs the shutter synchronizing signal to the shutter driving part  70  to operate the shutters  80  and  90 . From the above construction, when the scan line mode switch  40  selects the off mode to output the operation disable signal, the scan line controller  30  outputs the analog image signals R, G and B to the monitor  50  without separating them into the left eye image signal and the right eye image signal, and when the scan line mode switch  40  selects the on mode to output the operation enable signal, the scan line controller  30  separates the analog image signals R, G and B into the left eye image signal and the right eye image signal and outputs the separated image signals to the monitor  50 . 
     The scan line controller  30  applies also the shutter synchronizing signal(F and G in FIG. 3) to the shutter driving part  70 . The construction and operation of the scan line controller  30  and the shutter driving part  70  will be more detailed described with reference to the FIGS. 2 and 3. 
     The shutter driving part  70  operates the left eye shutter  80  and the right eye shutter  90  in respond to the shutter synchronizing signal. When an user puts on his shutters  80  and  90  and stares at the monitor  50 , the user can perceive the stereoscopic images. 
     Hereinafter, the operation of the apparatus according to the presents invention will be more detailed described with reference to the FIGS. 2 and 3. 
     The second voltage V 2  from the multipower  10  is applied to the analog switch  31 , the synchronizing buffer  32 , the vertical ½ divider  33 , the vertical blanking signal sensor  34 , the horizontal ½ divider  35  and the control logic circuit  36 , respectively to be used as a scan line control voltage. Also, the second voltage V 2  is applied to the sensor  60  detecting the image input signals and the 3-states buffer  71  in the shutter driving part  70  to be used as the control voltage controlling the shutters  80  and  90 . The third voltage V 3  is applied to the shutter drivers  72  and  73  in the shutter driving part  70  to be used as an operation voltage of the shutters  80  and  90 . 
     The analog image signals R, G and B(A in FIG. 3) is input to the analog switch  31 , the vertical synchronizing signal (V_Sync) (B in FIG. 3) and the horizontal synchronizing signal (H_Sync) (C in FIG. 3) are input to the synchronizing signal buffer  32  and the sensor  60 . 
     The vertical synchronizing signal V_Sync from the synchronizing signal buffer  32  is input to the monitor  50 , the vertical ½ divider  33  and the vertical blanking signal sensor respectively, and the horizontal synchronizing signal H_Sync from the synchronizing signal buffer  32  is input to the monitor  50  and the horizontal ½ divider  35  respectively. 
     The output signals V_Q and V_{overscore (Q)} from the vertical ½ divider have a 50% duty rate of the vertical synchronizing signal from the synchronizing signal buffer  32 , and the output signals H_Q and H_{overscore (Q)} from the horizontal ½ divider  35  have a 50% duty rate of the horizontal synchronizing signal from the synchronizing signal buffer  32 . 
     The vertical blanking signal sensor  34  detects whether or not the vertical synchronizing signal V_Sync has a blank, and outputs the vertical blanking signal V_blank if the V_Sync has a blank. The vertical blanking signal V_blank is input to the reset terminal of the horizontal ½ divider  35 . The horizontal vertical ½ divider  35  is initialized by the vertical blanking signal V_blank. After the initialization, when the horizontal synchronizing signal from the synchronizing signal buffer  32  is input to the horizontal ½ divider  35 , the divider  35  outputs the synchronizing signal having a 50% duty rate of the horizontal synchronizing signal from the synchronizing signal buffer  32 . 
     The output signals H_Q, H_{overscore (Q)}, V_Q and V_{overscore (Q)} are input to the control logic circuit  36 . 
     The control logic circuit  36  outputs a control signal to the analog switch  31  in respond to the on/off control signals from the scan line mode switch  40 . When the scan line mode switch  40  outputs the operation disable signal to the control logic circuit  36  by the selection of the off mode, the control logic circuit  36  outputs an off control signal to the analog switch  31 . 
     The analog switch  31  transfers the analog image signals R, G and B from the VGA card  20  to the monitor  50  according to the off control signal from the control logic circuit  36 . On the other hand, when the scan line mode switch  40  outputs the operation enable signal to the control logic circuit  36  by the selection of the on mode, the control logic circuit  36  outputs an on control signal(D in FIG. 3) to the analog switch  31 . In respond to the control signal from the control logic circuit  36 , the analog switch  31  outputs the analog image signals R, G and B as shown in E of FIG. 3 to the odd scan line and generates the blanking signal on the even scan line. Otherwise the analog switch  31  outputs the analog image signals R, G and B to the even scan line and generates the blanking signal on the odd scan line. 
     The analog switch  31  may be a usual switch as shown FIG. 4 or other electronic type switches. 
     The analog switch  31  of FIG. 4 is constructed to have two input terminals and one output terminal for each analog image input signal R, G or B. In FIG. 4, symbols a, d and g denote the input terminals receiving the each analog image input signal R, G or B from the VGA card  20  respectively, and symbols b, e and h denote the ground terminals and symbols c, f and i denote the output terminals respectively. The analog switch  31  is controlled by the control signal from the control logic circuit  36 . When the on control signal is input to the analog switch  31 , the input terminals a, d and g are connected to the output terminals c, f and i respectively to output the analog image signals R, G and B to the monitor  50 . Accordingly, the stereoscopic images can be displayed on the monitor  50 . On the other side, when the off control signal is input to the analog switch  31 , the ground terminals b, e and h are connected to the output terminals c, f and i respectively, to not output the analog image signals. Accordingly, the black is displayed on the monitor  50 . 
     The sensor  60  detects whether or not the vertical synchronizing signal or the horizontal synchronizing signal is input thereto. If the signal is detected, the sensor  60  outputs the detected signal to the 3-states buffer  71 . 
     When the detected signal is input to the 3-states buffer  71 , the buffer  71  transfers the shutter synchronizing signals(F and G in FIG. 3) from the vertical ½ divider  33  to the shutter drivers  72  and  73 . However any image signal is not detected by the sensor  60 , the buffer  71  becomes a cut-off state. 
     The shutter drivers  72  and  73  amplify the third voltage V 3  to voltage level for driving the shutter  80  and  90 , and outputs the amplified voltage to the phase switch  74  for switching the phase of the stereoscopic image. 
     If the left images and right eye images are not synchronized with the left eye shutter  80  and right eye shutter  90  respectively, the phase switch  74  has a function enabling the left eye image and right eye image to synchronize the left eye image shutter  80  and the right eye shutter  90  respectively by activating the shutters  80  and  90 . 
     The phase switch  74  may be constructed by using a usual switch as shown in FIG. 5 or other electronic type switches. In FIG. 5, when the shutter driving signals are input to the input terminals j and I of the phase switch  74 , the phase switch  74  outputs the shutter driving signals through two output terminals (k and n) to the shutter  80  and  90 . When the shutter driving signals are input to the shutters  80  and  90 , the left eye shutter  80  and the right eye shutter  90  become operable. 
     As above described according to the present invention, if the scan line mode switch  40  outputs the operation enable signal to the scan line controller  30 , it is possible to display the stereoscopic images consisted of the left eye images and the right eye images on a display device using the CRT monitor  50 . Accordingly when an user puts on his(or hers) shutters  80  and  90  and stares at the monitor  50 , the user can perceive the stereoscopic images. It is possible to easily implement the stereoscopic images in the computer system without considering the development for the individual control programs according to the types of VGA cards or the compatibility of computers. 
     While the present invention has been particularly shown and described with reference to the particular embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be effected therein without departing from the spirit and scope of the invention as defined by the appended claims.