Abstract:
An apparatus for information display for displaying not only periodic information in accordance with schedule, but also non-periodic information regardless of the schedule, to passengers and passersby in stations, airports, harbors, bus terminals and streets, and the like. The apparatus comprises an information-storing section for storing a plurality of non-periodic information to be displayed regardless of the schedule, an input circuit for receiving a plurality of input signals transmitted from an external device or a remote place and display control section for simultaneously displaying the non-periodic information and periodic information which correspond to the kind of an input signal, when the apparatus receives this input signal from the external apparatus or the remote place. The apparatus may be a multi-screen display type having a plurality of screens. In this case, a combined screen data consisting of a non-periodic information and a periodic information can be displayed, or the non-periodic information or the periodic information can be displayed, on at least one of the screens.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a technique of displaying information, particularly to an apparatus for information display to passengers and passersby in stations, airports, harbors, bus terminals, buildings and streets, and the like. More particularly, the invention relates to a technique which is useful and efficient when applied to display apparatuses and the like that can display non-reservation information alone in one screen, or reservation-based information and non-reservation information together in one screen. 
     There is information, such as advertisement, that should be displayed in time frame by some of the display devices installed in the stations and streets, said time frames and said display devices having been designated in schedule. There is other information that should be displayed for convenience and safety for the passengers and passersby. Such information is, for example, the messages of “The train is coming into the track” and “The train is now overdue” made in the stations. On the streets, such information may be special newscasts and the like. 
     Hitherto, display devices for displaying information, such as static pictures, moving pictures and the like, in desired time frame have been of the type that sequentially reproduces items of information recorded on, for example, video tape. These display devices are technically disadvantageous, because they cannot display information not designated in the schedule or display data in any order changed. 
     As disclosed in Japanese Patent Application Laid-Open No. 9-244600, a display device is known that displays recorded information reproduced from a video tape and then stored into a data storage section such as a server, in the time frame designated in schedule. However, this display device has no means for detecting any information which is other than the information designated in the schedule and which should yet be displayed. Nor is this display apparatus designed to display any data items other than those designated in the reservation schedule. 
     An object of the present invention is to provide an information-displaying technique that can display various types of information in various modes whether the information is designated by schedule or not. 
     SUMMARY OF THE INVENTION 
     An apparatus for information display according to the present invention comprises information-storing section for storing a plurality of various data that do not accord with schedule, an input circuit for receiving a plurality of input signals from an external device or a remote place, and a display control means for displaying the data corresponding to the kind of the input signal, prior to any data that accords with the schedule when an input signal is received from the external devices or the remote places. Thus, the apparatus for information display can display data generated of the schedule, such as a message “The train is coming into the track” corresponding to an input signal generated in any external devices (e.g., a train service control device) or “a special newscast” corresponding to an input signal received through a transmitting/receiving circuit. 
     The apparatus for information display comprises display control means designed not to cancel, interrupt or inhibit the displaying of data that accord with the schedule, when data that do not accord to the schedule are displayed prior to the data that accord with the schedule. The display control means perform the following functions. 
     The apparatus for information display comprises screen-combining means for combining data to be displayed in accordance with the schedule, together with data to be displayed regardless of the schedule. In this case, the display control means cause the screen-combining means to combine these data, thereby to display one combined screen data consisting of these data. Thus, the data that do not according with the schedule can be displayed on the same display unit, without interrupting the displaying of the data that accord with the schedule. 
     The display control means can start the displaying of the data that do not accord with the schedule, at a timing of switching the data that accord the schedule, when an input signal is received from the external device or the remote place. Hence, the data that do not accord with the schedule can be displayed, without interrupting the displaying of the data that accord with the schedule. 
     The apparatus for information display may be a multi-screen apparatus having a plurality of independent screens. In this case, the display control means display data that do not accord with the schedule on one or more screens, without jeopardizing the displaying on the other screens. 
     Moreover, the display control means perform some additional functions, not to jeopardize the displaying of data not according with the schedule or the displaying of data according to the schedule, if new data to be displayed have been generated regardless of the schedule. 
     First, when a new signal is received from an external device or a remote place while data that accord with the schedule are being displayed, the display control means compare, in the precedence, the data being displayed with the data corresponding to the input signal. If the priority of the data being displayed is higher, the display control means start the displaying of the data corresponding to the input signal after the data have been completely displayed. If the priority of the data being displayed is lower, the display control means immediately start the displaying of the data corresponding to the input signal. 
     Secondly, if the apparatus for information display has a plurality of screens for displaying a plurality of independent screen data at the same time, a new signal may be received from an external device or a remote place while data that do not accord with the schedule are being displayed on one or more of the screens. In this case, the display control means display the data corresponding to the input signal on one or more screens which are displaying data that accords with the schedule. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic representation of an apparatus for information display according to an embodiment of the present invention. 
     FIG. 2 is a flow chart explaining the operation of the control circuit provided in the apparatus for information display according to an embodiment of the invention; 
     FIG. 3A is a diagram showing a screen displaying the information represented by an external input signal to the apparatus for information display according to an embodiment of the invention. 
     FIG. 3B is a diagram depicting a screen displaying a special newscast, along with other information, in the apparatus for information display according to an embodiment of the invention. 
     FIG. 3C is a diagram illustrating a screen displaying a special advertisement, along with a periodic guidance, in the apparatus for information display according to an embodiment of the invention. 
     FIG. 3D is a diagram showing a screen displaying seasonal background, along with the apparatus for information display by an external input signal, in the apparatus for information display according to an embodiment of the invention. 
     FIG. 4 is a diagram depicting four screens displaying information in the apparatus for information display according to an embodiment of the invention. 
     FIG. 5 is a diagram schematically depicting the format of storing information in the information-storing section of the apparatus for information display according to an embodiment of the invention. 
     FIG. 6 is a table illustrating schedule used in a modification of the apparatus for information display according to an embodiment of the invention. 
     FIG. 7 is a schematic representation of a control mode of the apparatus for information display according to an embodiment of the invention. 
     FIG. 8 is a diagram illustrating another control mode of the apparatus for information display according to an embodiment of the invention. 
     FIG. 9 is a diagram representing another control mode of the apparatus for information display according to an embodiment of the invention. 
     FIG. 10 is a diagram explaining another control mode of the apparatus for information display according to an embodiment of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention will be described, with reference to the accompanying drawings. 
     FIG. 1 is a schematic representation of an apparatus for information display according to an embodiment of the invention. 
     A display device  1  of an apparatus for displaying information comprises n orderly arranged display units X 1  to Xn. The units X 1  to Xn have display memories Y 1  to Yn, respectively. The memories store screen data of digital information to be displayed by the units. Unless each date content of the memories is sequentially updated, each display unit of the units X 1  to Xn keeps the same picture and thereafter becomes a static picture. If each date content of the memories is sequentially updated, for example,  30  times a second, each display unit of the units X 1  to Xn shows a moving picture. 
     The units X 1  to Xn are connected to a display circuit  6  of a control device  2  by an interface line  13 . The interface line  13  transmits undated data to each of the units X 1  to Xn because of updating the memories Y 1  to Yn. The updated data consist of a display-unit number, RGB data (representing the color components of red, green, and blue of dots forming a screen), a horizontal synchronizing signal, a vertical synchronizing signal, and the like. The interface line  13  can be realized by using all purpose interface, such as an analog RGB interface, a digital RGB interface, or a USB (Universal Series Bus) interface. 
     In a case of using an analog RGB interface, the RGB data, horizontal synchronizing signal, and vertical synchronizing signal corresponding to an imaginary large screen that is composed of all screens of the units X 1  to Xn are transmitted to all the units X 1  to Xn. Screen data corresponding to the parts of the imaginary large screen are thereby taken in the units X 1  to Xn. Hence, the data are updated in each of the display memories Y 1  to Yn corresponding to each of the units X 1  to Xn. This holds true for a case of using the digital RGB interface. 
     In a case of using the USB interface, the display-unit members and RGB data corresponding thereto are transmitted to each of the units X 1  to Xn. The members Y 1  to Yn are updated because the units X 1  to Xn corresponding to the members take in the RGB data. 
     Further, in a case of using both of the analog RGB interface and the USB interface, the numbers are transmitted to the display device  1  through the latter interface, thus selecting the units X 1  to Xn. And the RGB data are transmitted to the display device  1  through the former interface, whereby the data are updated in the memories Y 1  to Yn incorporated. 
     The control device  2  comprises a control circuit  3 , an information-storing section  4 , a schedule storing section  5 , a display circuit  6 , a clock circuit  7 , an input circuit  8 , a data converting circuit  9 , a screen-data storing section  10 , a transmitting/receiving circuit  11 , and a power circuit  12 . The control circuit  3  controls operation of displaying information in the apparatus for information display according to an embodiment of the invention. The information-storing section  4  stores information for representing static pictures and moving pictures. The schedule storing section  5  stores a timetable which shows data and time frames to be displayed on the units X 1  to Xn, or determination of compound operation thereof. The display circuit  6  transmits screen data to each of the units X 1  to Xn through the interface line  13 . The clock circuit  7  holds information showing the date and time. The input circuit  8  receives an external input signal  16   a  with non-periodic display information  16   b  or information for indicating output timing and assigned priorities of the non-periodic information  16   b . The non-periodic information  16   b  is information of “The train is coming into the truck” from an external device through an input signal line  16 . The date converting circuit  9  receives a periodic display information  17   a  and changes the periodic information  17   a  into a digital information. The periodic information  17   a  is a picture signal transmitted from an external video recorder (VTR) or a tuner circuit through a picture signal line  17 . The screen-data storing section  10  stores a plurality of screen data. The transmitting/receiving circuit  11  transmits and receives an input/output signal  15   a  containing a non-periodic display information  15   b , a message and the like, from and to a remote place through a communication line  15 . The power circuit  12  supplies a DC current and the like to the other components of the control device  2  through a power line  14 . The screen-data storing section  10  has m screen areas Z 1  to Zm for storing screen data. 
     The control circuit  3  and the other circuits incorporated in the control device  2  can be realized by using electronic circuits, program control circuits having a microcomputer, semiconductor memories, and electronic parts. 
     The information-storing section  4  stores information content such as non-periodic information  16   b , the periodic information  17   a , the non-periodic display information  15   b , and the like, in a format as shown in FIG.  5 . 
     That is, the content includes a content ID  41 , a precedence  42 , a content  43 , composite flags  44 , and a composite content ID  45 . The content ID  41  distinguishes individual information. The precedence  42  represents priority order for disposing of display information. The content  43  comprises the non-periodic information  16   b , the periodic information  17   a , the non-periodic information  15   b , and the like. Each of the composite flags  44  indicates composite method (registration, vertical or horizontal division of the display screen, ratio of dividing the display screen, and the like) and determination of making the given display information synthetic. The composite content ID  45  indicates content as composite object in the storing section  4 . The precedence  42  can be set from lower level  1  to higher level  4  in priority order. 
     A timetable  50  taken in the schedule storing section  5  has, for example, a structure as shown in FIG.  6 . That is, the timetable  50  has a display-device number  50   a  in a row corresponding to the units X 1  to Xn, and a time frame  50   b  set at a prescribed regular interval (every 15 seconds in the example of FIG.  6 ), in a column. Each of entries  51  in the timetable  50  contains information comprising a content ID  51   a , a precedence  51   b , a composite flag  51   c , a composite content ID  51   d , and the like. The content ID  51   a  indicates content to be displayed at the time frame by the display device  1 . The precedence  51   b  represents the priority order of the content. 
     The operation of the apparatus for information display shown in FIG. 1 will now be described. FIG. 2 is a flow chart explaining how the control circuit  3  operates. FIGS. 3A to  3 D show example screens displayed by using the present invention. 
     Main information (content) to be displayed and the timetable  50  are stored into the information and schedule storing section  4 ,  5  through the data converting circuit  9  and transmitting/receiving circuit  11 , and are used to operate the control circuit  3  shown in FIG.  2 . 
     The operation of the control circuit  3  will be explained, with reference to the flow chart of FIG.  2 . 
     When started, the control circuit  3  is set in a waiting state at step A. In the waiting state, the control circuit  3  repeats operation determined by steps B, C, D, E and F, thereby waiting for one step thereof to occur. 
     In step B, the control circuit  3  refers to the timetable  50  and present time measured by the clock circuit  7 , and determines whether or not the present time is within starting time of the time frame  50   b  in the timetable  50 . If NO in step B, that is, if the present time is time to start displaying the periodic information  17   a  in accordance with the timetable  50 , the flow goes to step C. If YES in step B, that is, if the present time is time to start displaying the periodic information  17   a , the flow goes to step G. In step G, in accordance with information contained in the corresponding entry  51  in the timetable  50 , the control circuit  3  ( 1 ) reads the periodic information  17   a  from the information section  4 , ( 2 ) selects a screen area of the screen-data section  10 , ( 3 ) stores the screen data in each of the screen areas Z 1  to Zm, and ( 4 ) transmits the screen data to each of the units X 1  to Xn, thereby displaying the screen data. 
     Thereafter, the control circuit  3  is brought back into the waiting state again. If the corresponding periodic information  17   a  represents a static picture, the screen data represent one picture and remain the static picture until a next time frame  50   b  starts. 
     If the periodic information  17   a  represents a moving picture, the screen data are divided in a plurality of data items. The data items are sequentially transmitted to the units X 1  to Xn at regular intervals (e.g., every {fraction (1/30)} second), and therefore are displayed thereon. Thus, in step C, the control circuit  3  refers to time measured by the clock circuit  7 , thereby determining whether or not the present time is time to display a next time frame of the moving picture. If NO in step C, the flow goes to step D. If YES in step C, the flow goes to step H. In step H, the control circuit  3  ( 1 ) stores the screen data of the next time frame, in the screen area, ( 2 ) transmits the screen data to the units X 1  to Xn, thereby displaying the screen data. 
     Thereafter, the control circuit  3  is brought back into the waiting state again. Then, the sequence of these steps is repeated until the next time frame  50   b  starts. The moving picture is thereby displayed by the corresponding units X 1  to Xn. 
     Thus, it is possible to display the periodic information  17   a  which is either a static picture or a moving picture, in accordance with the schedule. 
     In step D, the control circuit  3  determines whether or not the input circuit  8  has received the external input signal  16   a  transmitted from the external apparatus. If NO in step D, the flow goes to step E. If YES in step D, the flow goes to step I. In step I, the control circuit  3  ( 1 ) reads in the non-periodic information h 6   b  corresponding to the signal  16   a  and stored in the storing section  4  in advance, ( 2 ) refers to the present time measured by the clock circuit  7  and to the timetable  50 , thereby selecting the time frame  50   b  in accordance with the first schedule set at that time, ( 3 ) selects the unit (unit number  50   a ) set in advance, and ( 4 ) alters content of the entry  51  in the timetable  50 , thereby changing the information to be displayed in the time frame  50   b  selected, from the periodic information ha in accordance with the schedule to the non-periodic information  16   b  corresponding to the input signal  16   a . Thereafter, the control circuit  3  is brought back into the waiting state. In step B, at starting time in a next time frame  50   b  selected, the flow goes to step G through step B. In step G, the control circuit  3  works in accordance with the timetable  50  that has been altered in step I. That is, the control circuit  3  ( 1 ) takes out the non-periodic information  16   b  corresponding to the external input signal  16   a , such as the message “The train is coming into the track,” from the information storing section  4 , ( 2 ) selects the screen area, ( 3 ) stores the screen data of the non-periodic information  16   b  corresponding to the external input signal  16   a , in the screen area selected, and ( 4 ) transmits the screen data to the corresponding display unit X 1  or Xn, thereby displaying the screen data. 
     Thus, the periodic information  17   a  can be switched to the non-periodic information  16   b  corresponding to the external input signal  16   a  without inerruption on switching way. The periodic information  17   a  depends on the timetable  50  in the corresponding to display unit. 
     FIG.  3 A and FIG. 7 show an example described above. 
     FIG. 3A shows an example in a state that the periodic information  17   a  in a display screen has already replaced by the displayed non-periodic information  16   b  corresponding to the input signal  16   a . The periodic information  17   a  corresponds to the previously displayed timetable  50 . In this case, if only one display unit has been selected as the above-mentioned units X 1  to Xn as shown in FIG. 1, the displaying of the periodic information  17   a  depending on the timetable  50  in remainder of the units will not be influenced by the selected one. 
     FIG. 7 is a diagram representing a control mode of updating the timetable  50  by the above-mentioned steps. The storing section  4  stores content of the non-periodic information  16   b  that corresponds to the external input signal  16   a . Wherein, assume that the content of the non-periodic information  16   b  is level  3  of precedence and means a content ID  101  that represents a character row of “The train is coming into the track.” As indicated above, contents of the entry  51  selected are altered when the entry  51  has level  1  or  2  of precedence. 
     A new external input signal  16   a ′ may be detected when the display unit X 1  . . . Xn displays the non-periodic information  16   b  corresponding to the already transmitted external input signal  16   a . If so, the control circuit  3  ( 1 ) reads the non-periodic information  16   b ′ which corresponds to the external input signal  16   a ′ and is stored in the information-storing section  4 , ( 2 ) refers to the timetable  50  and the present time measured by the clock circuit  7 , thereby selecting the time frame  50   b  that accords with the first timetable on the basis of the present time, ( 3 ) selects another display unit because the timetable  50  has already been altered so as to cause the display unit to display the non-periodic information  16   b  corresponding to another external input signal  16   a  in the previously set units, ( 4 ) alters the timetable  50  again, thereby changing the information to be displayed in the selected time frame  50   b , from the periodic information  17   a  that accords with the other schedule, to the non-periodic information  16   b ′ that corresponds to the new external input signal  16   a′.    
     Thus, the non-periodic information  16   b  corresponding to the external input signal  16   a  once received can be displayed without influence from the new external input signal  16   a′.    
     Thereafter, in step E, the control circuit  3  determines whether or not the transmitting/receiving circuit  11  has received the non-periodic information  15   b , such as a special newscast. If the transmitting/receiving circuit  11  has not received, the flow goes step F. If the transmitting/receiving circuit  11  has received, the flow goes to step J. In step J, the control circuit  3  determines whether the non-periodic information  15   b  should be displayed immediately or not. If the non-periodic information  15   b  needs to be displayed at once, the flow goes to step L. Otherwise, the flow goes to step K. 
     FIG.  3 B and FIG. 8 show an example displayed by the periodic information  17   a  combined with “special newscast” immediately (the non-periodic information  15   b ). “Special newscast” is contained in the input signal  15   a  that has been received by the transmitting/receiving circuit  11 . How the special newscast is so displayed will be explained below. 
     In step E shown in FIG. 2, when detecting the receipt of the special newscast (non-periodic information  15   b ) at the transmitting/receiving circuit  11 , the control circuit  3  determines that the non-periodic information  15   b  should be displayed in step J immediately, and then executes step L. That is, the control circuit  3  ( 1 ) stores “special newscast” (non-periodic information  15   b ) in the information-storing section  4 , ( 2 ) selects the screen area (a) that stores the screen data representing a motion picture in which “special newscast” (non-periodic information  15   b ) will be displayed, ( 3 ) selects the display unit that displays “special newscast” (non-periodic information  15   b ) after being combined thereby, ( 4 ) combines the screen of “special newscast” (non-periodic information  15   b ), with the screen data stored in the screen area (b) which is being displayed by the selected display unit, ( 5 ) stores the composite screen data in the screen area (b), and ( 6 ) transmits the combined screen data to the selected display unit, thereby displaying the composite screen data. Then, the control circuit  3  is brought back into the waiting state. 
     In this case, since “special newscast” (non-periodic information  15   b ) is a moving picture, the composite screen data must sequentially be transmitted to the display unit at regular intervals (e.g., every {fraction (1/30)} second). Thus, the composite screen data are handled in the same way as that of the moving picture described above. That is, in step C, the control circuit  3  refers to time measured by the clock circuit  7 , thereby determining whether or not the time has come to display the next time frame of the moving picture. If YES, the control circuit  3  performs step H. In step H, the control circuit  3  ( 1 ) stores the screen data for the next frame, in the screen area (b), ( 2 ) transmits the composite screen data to the display unit, thereby displaying the composite screen data. Thereafter, the control circuit  3  return the waiting state. Then, the control circuit  3  sequentially repeats these steps until “special newscast” (non-periodic information  15   b ) ends. Therefore, the selected display unit can display the moving picture combined with “special newscast” (non-periodic information  15   b ). 
     Thus, “special newscast” (non-periodic information  15   b ) received via the transmitting/receiving circuit  11  can be displayed at once while the periodic information  17   a  is displayed in accordance with the timetable  50 . Although not shown in FIG. 2, in the same way, while the periodic information  17   a  is displayed in accordance with the timetable  50 , the non-periodic  16   b  that corresponds to the external input signal  16   a  received via the input circuit  8  can be immediately displayed. 
     FIG. 8 is a diagram illustrating a control mode of updating the timetable  50  by performing the above-mentioned steps. The information-storing section  4  stores the content of the non-periodic information  15   b  that corresponds to the message (the input signal  15   a ). Assume that the content of the non-periodic information  15   b  represents a moving picture of “special newscast”. The content of the non-information  15   b  is combined with the screen data corresponding to the entry  51  selected in the timetable  50  and thereafter is displayed. 
     Without combining the screen data described above, the displaying data on the display unit may be interrupted, and the display unit may immediately display either the non-periodic information  15   b  received via the transmitting/receiving circuit  11  or the non-periodic information  16   b  corresponding to the external input signal  16   a  received via the input circuit  8 . That is, the data displayed by the selected display unit may not be, for example, the periodic information  17   a  that accords with the timetable  50 , but may be either the non-periodic information  15   b  that has been received via the transmitting/receiving circuit  11 , or the non-periodic information  16   b ′ that corresponds to another external input signal  16   a ′ received via the input circuit  8 . In this case, both of the non-periodic information  15   b ,  16   b ′ which are compared with the non-periodic information  16   b  to be displayed immediately, in order of precedent. If the latter non-periodic information  16   b  has higher priority, the displaying of the former non-periodic information  15 ,  16   b ′ are interrupted, and the displaying is switched to the latter non-periodic information  16   b  at once. Conversely, if the latter non-periodic  16   b  has lower priority, the displaying is switched to new non-periodic information  16   b  after the displaying of the former  15   b ,  16   b ′ has been finished. 
     FIG.  3 C and FIG. 9 show an example displayed by a train-transfer guidance (periodic information  17   a ) combined with the non-periodic information  15   b , such as a special advertisement, which has been received via the transmitting/receiving circuit  11 . The displaying of train-transfer guidance is on a periodic staic picture. The above-mentioned case will be described below. 
     In step E shown in FIG. 2, the control circuit  3  detects receipt of the instruction for “special advertisement” (the non-periodical information  15   b ) to be combined with the train-transfer guidance on a periodic static picture through the transmitting/receiving circuit  11 . Then, the flow goes to step J. In step J, the control circuit  3  determines whether or not the non-periodic information  15   b  need to be displayed immediately (that is, the information  15   b  has level  2  in order of precedence). If NO, the flow goes to step K. In step K, the control circuit  3  ( 1 ) stores the screen data of “special advertisement” (non-periodic information  15   b ) received, in the information-storing section  4 , and ( 2 ) changes the content (the composite flag  51   c  and composite content ID  51   d  of the entry  51  in the timetable  50 , so that “special advertisement” (the non-periodic information  15   b ) may be combined with and displayed together with periodic guidance (periodic information  17   a ) on the static picture when the periodic guidance is displayed. Then, the control circuit  3  returns the waiting state. 
     Instead of the above-mentioned method, there is also another method for changing the composite flag  44  of the static picture guidance (periodic information  17   a  or the like stored in the information -storing section  4 , and the composite content ID  45  for indicating content to be combined). 
     Then, the flow returns to step B after the above-mentioned performance. In step B, time comes to start the next time frame  50   b  in which the periodic guidance (the periodic information  17   a ) should be displayed on the static picture. The flow goes from step B to step G. In step G, in accordance with the altered timetable  50 , the control circuit  3  ( 1 ) reads the screen data for the periodical guidance (the periodic information  17   a ), from the information-storing section  4 , ( 2 ) selects the screen area, ( 3 ) stores in the screen area selected, screen data provide by combined the periodic guidance screen (the periodic information  17   a  and “the special advertisement” (the non-periodic information  15   b ) with each other, and ( 4 ) transmits the composite screen data to the corresponding display unit, thereafter displaying this composite screen data. Thus, it is possible to display the composite data shown in FIG.  3 C. Although not shown in FIG. 2, in the same way, the non-periodic information  16   b  that corresponds to the external input signal  16   a  received via the input circuit  8  can be combined with and displayed together with the periodic information ha that accords with the timetable  50 . 
     FIG. 9 is a diagram illustrating a control mode of updating the timetable  50  by performing the above-mentioned steps. The information-storing section  4  stores the content of the non-periodic information  15   b  that corresponds to the input signal  15   a . Assume that the content of the non-periodic information  15   b  is a “special advertisement”. In this case, the content of the periodic information  17   a , which represents the train-transfer guidance combined on the periodic static picture, is already stored in the information-storing section  4 . Display timing for the periodic information ha is already registered as content ID AAA in the timetable  50 . Composite display combined by the screen data of the above-mentioned steps is accomplished by changing the composite flag  51   c  and composite content ID  51   d  of the entry  51 , or by changing the composite content ID  45  and composite flag  44  of the periodic information  17   a  which is stored in the information-storing section  4  and which represents “train-transfer guidance” on the periodic static picture. 
     FIG.  3 D and FIG. 10 show an example displayed by “seasonal background” (the non-periodic information  15   b ) combined with the non-periodic information  16   b  corresponding to the external input signal  16   a . “Seasonal background” is received through the transmitting/receiving circuit  11 . The above-mentioned case will be described below. 
     In step E shown in FIG. 2, the control circuit  3  detects receipt of the instruction for “seasonal background” to be combined with an external input signal  16   a  though the transmitting/receiving circuit  11 . Then, the flow goes to step J. In step J, the control circuit  3  determines whether or not “seasonal background” (non-periodic information  15   b ) need be displayed immediately (for example, order of precedence is level  2 ), the flow goes to step K. In step K, the control circuit  3  ( 1 ) stores the received screen data of “seasonal background” (non-periodic information  15   b ) in the information-storing section  4 , and ( 2 ) changes the composite flag  44  and the content ID  45  (designating the “seasonal background”, i.e., non-periodic information  15   b ) corresponding to the content of the non-periodic information  16   b  stored in the information-storing section  4 , so that the “seasonal background” may be combined with and displayed together with the non-periodic information  16   b  corresponding to the external input signal  16   a , when the non-periodic information  16   b  is displayed. Then, the control circuit  3  gets back the waiting state. 
     Thereafter, the flow goes through step D to step I. In step I, the control circuit  3  alters the timetable  50  so as to display the non-periodic information  16   b  corresponding to the external output signal  16   a  within the selected time frame  50   b  and to display seasonal background” (the non-periodic information  15   b ) after being combined with the information  16   b . Thereafter, in step B, when starting time within the time frame  50   b  comes, the control circuit  3  displays the non-periodic information  16   b  corresponding to the external input signal  16   a . The flow goes to step G. In step G, in accordance with the timetable  50  that has been thus altered, the display unit displays the screen data that combines of the “seasonal background” (non-periodic information  15   b ) and the non-periodic information  16   b  with each other. Thereby, the combined screen data shown in FIG. 3C can be displayed. 
     FIG. 10 is a diagram illustrating a control mode of updating the timetable  50  by performing the above-mentioned steps. The information-storing section  4  and the timetable  50  already store the non-periodic information  16   b  corresponding to the external input signal  16   a . The non-periodic information  15   b  that represents “seasonal background” is stored in the information-storing section  4 . Further, after being changed by the control circuit  3 , the composite flag  44  and content ID  45  of the non-periodic information  16   b  are combined with and displayed together with the non-periodic information  15   b.    
     Next, step F shown in FIG. 2 is a step for detecting an error process of the apparatus for information display according to an embodiment of the invention. If step F detects no error process, the control circuit  3  is brought back into the waiting state again. If step F detects an error process, the flow goes to step M. In step M, the control circuit  3  transmits an error message (the input signal  15   b ) via the transmitting/receiving circuit  11  to a remote place, so that the cause of the error process may soon be eliminated. Thereafter, the control circuit  3  gets back the waiting state again. 
     Thus far, in the present invention, a case where one display unit displays one screen is described. However, it is possible to divide one screen into a plurality of regularly arranged parts (e.g., four parts arranged in two rows and two columns), whereby to display all parts as a wider screen, respectively, on a plurality of display units. FIG. 4 shows the screens of four display units X 1  to X 4  divided for displaying one magnified screen data. 
     As has been described, the apparatus for information display according to an embodiment of the invention not only displays a desired periodic data  17   a  in a desired time frame  50   b  on a desired screen in accordance with the schedule, but also can display non-periodic information  15   b  and  16   b  that have not been reserved and can display combined screen data consisting of the periodic information  17   a  and the non-periodic information  15   b  or  16   b . Thus, the apparatus for information display displays various data at desired times in accordance with the precedence of each data, enhancing the convenience and safety for the passengers and passersby who see and hear the data displayed. 
     Since the non-periodic information  15   b  and  16   b  are transmitted to the apparatus for information display from external devices, it is possible for the external devices to update, in real time, the non-periodic information  15   b  and  16   b  to be displayed. 
     Further, data, such as an error message indicating that the apparatus for information display has made an error, can be transmitted via the transmitting/receiving circuit  11  to a remote place. Hence, the error can be soon diagnosed and eliminated at the remote place. 
     The present invention made of the inventor has been described in detail, with reference to the preferred embodiments. Nevertheless, the invention is not limited to the embodiments. Needless to say, various changes can be made without departing the spirit and scope of the invention. 
     For example, order of precedence between a periodic information and a non-periodic information may be depended on the precedence assigned to the hardware ports through which the data are input and output, respectively. 
     The apparatus for information display according to the present invention can display various kinds of data in various forms, said data including those which accord with schedule and those which have been generated regardless of the schedule. This is an advantage of the present invention. 
     Moreover, the apparatus for information display can display not only data that accord with schedule, but also data generated regardless of the schedule. The apparatus for information display, therefore, serves to enhance the convenience and safety for the passengers and passersby who see and hear the data displayed. This is another advantage of the present invention.