BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to receiving apparatuses and methods, transmitting apparatuses and methods, and transmission media, and in particular, to a receiving apparatus and method, a transmitting apparatus and method, and a transmission medium which are used for receiving and transmitting an image signal with electronic program guide information (hereinafter referred to as “EPG”). 
     2. Description of the Related Art 
     Recently, a system has become known in which a television broadcast signal with, e.g., EPG is transmitted and the signal is received and displayed by domestic receiving apparatuses. 
     In this system, when program information forming the EPG is displayed, the program information can be displayed in the order of broadcasting stations designated by a user. The “StarSight” (service mark) and the “GuidePlus+” (service mark) are known examples of this system in North America. 
     In the case where a particular broadcasting station transmits EPG including program information from all broadcasting stations, a receiving end treats program information from the particular broadcasting station as equivalent to program information from the other broadcasting stations. Thus, the particular broadcasting station cannot benefit by providing the information on all the programs. 
     In addition, when the user, who is watching a program from a predetermined broadcasting station, recognizes a program to be broadcast after the present program, program information is displayed in the order of broadcasting stations initially designated by the user, which requires the user to spend time finding a program from the desired broadcasting station. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a receiving apparatus and method, a transmitting apparatus and method, and a transmission medium which are used to display program information so as to reflect an intention of a sponsor for the program information and be easily usable by a user. 
     To this end, according to a first aspect of the present invention, the foregoing object has been achieved through provision of a receiving apparatus for receiving an image signal transmitted from a transmitting end, the receiving apparatus including: receiving means for receiving the image signal; first output means for outputting the image signal received by the receiving means to a display; extracting means for extracting EPG added to the image signal received by the receiving means; alteration means for altering the display format of the EPG when the EPG is displayed on the display, in accordance with predetermined information; and second output means for outputting the EPG altered by the alteration means to the display. 
     According to a second aspect of the present invention, the foregoing object has been achieved through provision of a receiving method for receiving an image signal transmitted from a transmitting end, the receiving method including: a receiving step for receiving the image signal; a first output step for outputting the image signal received in the receiving step to a display; an extracting step for extracting EPG added to the image signal received in the receiving step; an alteration step for altering the display format of the EPG when the EPG is displayed on the display, in accordance with predetermined information; and a second output step for outputting the EPG altered in the alteration step to the display. 
     According to a third aspect of the present invention, the foregoing object has been achieved through provision of a transmission medium for transmitting a computer program used in a receiving apparatus for receiving an image signal transmitted from a transmitting end, in which the computer program includes: a receiving step for receiving the image signal; a first output step for outputting the image signal received by the receiving step to a display; an extracting step for extracting EPG added to the image signal received in the receiving step; an alteration step for altering the display format of the EPG when the EPG is displayed on the display, in accordance with predetermined information; and a second output step for outputting the EPG altered in the alteration step to the display. 
     According to a fourth aspect of the present invention, the foregoing object has been achieved through provision of a transmitting apparatus for transmitting an image signal to a receiving end, the transmitting apparatus including: first generating means for generating the image signal; second generating means for generating EPG; third generating means for generating information representing a broadcasting station providing the EPG; adding means for adding the EPG generated by the second generating means and the information representing the broadcasting station, which is generated by the third generating means to the image signal generated by the first generating means; and transmitting means for transmitting to the receiving end the signal obtained by adding the EPG and the information representing the broadcasting station to the image signal. 
     According to a fifth aspect of the present invention, the foregoing object has been achieved through provision of a transmitting method for transmitting an image signal to a receiving end, the transmitting method including: a first generating step for generating the image signal; a second generating step for generating EPG; a third generating step for generating information representing a broadcasting station providing the EPG; an adding step for adding the EPG generated in the second generating step and the information representing the broadcasting station, which is generated in the third generating step, to the image signal generated in the first generating step; and a transmitting step for transmitting to the receiving end the signal obtained in the adding step by adding the EPG and the information representing the broadcasting station to the image signal. 
     According to a sixth aspect of the present invention, the foregoing object has been achieved through provision of a transmission medium for transmitting a computer program used in a transmitting apparatus for transmitting an image signal to a receiving end, wherein the computer program includes: a first generating step for generating the image signal; a second generating step for generating EPG; a third generating step for generating information representing a broadcasting station providing the EPG; an adding step for adding the EPG generated in the second generating step and the information representing the broadcasting station, which is generated in the third generating step, to the image signal generated in the first generating step; and a transmitting step for transmitting to the receiving end the signal obtained in the adding step by adding the EPG and the information representing the broadcasting station to the image signal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram showing a first embodiment of a transmitting apparatus according to the present invention. 
         FIG. 2  is a flowchart illustrating a process executed in the transmitting apparatus shown in  FIG. 1 . 
         FIG. 3  is EPG with provider information. 
         FIG. 4  is a block diagram showing a receiving apparatus according to one embodiment of the present invention. 
         FIG. 5  is a flowchart illustrating a process executed in the receiving apparatus shown in  FIG. 4 . 
         FIG. 6  is an example of an image displayed on a cathode ray tube, which is obtained by executing the process shown in  FIG. 5 . 
         FIG. 7  is a normally displayed EPG image. 
         FIG. 8  is an image displayed on a cathode ray tube, which is obtained by executing the process shown in  FIG. 5 . 
         FIG. 9  is a block diagram showing a second embodiment of a receiving apparatus according to the present invention. 
         FIG. 10  is a flowchart illustrating a process executed in the receiving apparatus shown in  FIG. 9 . 
         FIG. 11  is a table showing the correspondence between receiving frequencies and channel Ids which are stored in the ROM shown in  FIG. 9 . 
         FIG. 12  is an image displayed on a cathode ray tube, which is obtained by executing the process shown in  FIG. 10 . 
         FIG. 13  is a block diagram showing a third embodiment of a receiving apparatus according to the present invention. 
         FIG. 14  is a flowchart illustrating a process executed in the receiving apparatus shown in  FIG. 13 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows a block diagram of an embodiment of a transmitting apparatus according to the present invention. 
     In  FIG. 1 , an optical image and sound of a subject is input to a television camera  1 , and the television camera  1  generates and outputs the corresponding image signal and sound signal. A signal to which a sound signal has been added will be simply referred to as an “image signal” below. 
     An editor  2  records the image signal output from the television camera  1 , and properly combines a plurality of recorded image signals to generate an image signal constituting one program. 
     An EPG generator  4  generates and outputs EPG (whose details will be described below) composed of program information from a plurality of broadcasting stations. 
     A provider information generator  5  generates information on broadcasting stations as EPG providers, such as “ASAHI”. 
     A combining unit  3  adds the EPG output from the EPG generator  4  and the provider information output from the provider information generator  5  to the image signal output from the editor  2 , and outputs it. 
     The combining unit  3  superposes, for example, the EPG and the provider information on each other in a vertical retrace blanking period of the image signal, and outputs it. 
     A transmitter  6  modulates a carrier in accordance with the image signal output from the combining unit  3 , and amplifies the power of the carrier. 
     An antenna  7  transmits the carrier output from the transmitter  6  to domestic receivers. 
     Next, the operation of the above-described embodiment will be described with reference to the flowchart shown in  FIG. 2 . 
       FIG. 2  shows a flowchart illustrating one process executed by the transmitting apparatus shown in  FIG. 1 . 
     In step S 1  of this process, an image signal output from the television camera  1  is supplied to the editor  2 , in which it is once recorded and the image is subsequently edited so as to form a program having a predetermined length. The edited image signal is output to the combining unit  3 . 
     In step S 2 , the EPG generator  4  generates and supplies EPG to the combining unit  3 . 
     In step S 3 , the provider information generator  5  generates and supplies provider information to the combining unit  3 . 
     In step S 4 , the EPG supplied from the EPG generator  4  and the provider information supplied from the provider information generator  5  are added to the image signal supplied from the editor  2 . In other words, the combining unit  3  initially adds the provider information supplied from the provider information generator  5  to the EPG supplied from the EPG generator  4 . 
       FIG. 3  shows one example of the EPG, to which the provider information (provider tag) has been added. In this example, at the start of the EPG, “ASAHI” as a provider tag is disposed between two pairs of brackets indicating the type of information. In other words, just after &lt;PROVIDER TAG&gt; indicating the start and type of information, provider tag “ASAHI” is disposed, and &lt;/PROVIDER TAG&gt; indicating the end of information is disposed. 
     Subsequently, &lt;BROADCAST FILE  1 &gt; to &lt;BROADCAST FILE  6 &gt; representing programs are disposed. For example, concerning broadcast file  1 , &lt;BROADCAST FILE  1 &gt; indicating the type and start of information is displayed. Next, subsequently to &lt;BROADCAST DATE&gt; indicating a broadcast date, the date on which the broadcast file  1  is broadcast: Dec. 24, 1997, 16:00-16:10; and &lt;/BROADCAST DATE&gt; representing the end of information are disposed. Subsequently, “SOGO” indicating a broadcasting station is disposed between &lt;BROADCASTING STATION&gt; and &lt;/BROADCASTING STATION&gt;, and “NEWS” indicating a program name is disposed between &lt;PROGRAM NAME&gt; and &lt;/PROGRAM NAME&gt;. In the same manner, the broadcast files  2 - 6  are disposed. 
     The EPG to which the provider tag has been added is superposed on the image signal, for example, its vertical retrace blanking period, by the combining unit  3 . The superposed image signal is output to the transmitter  6 . 
     In step S 5 , the transmitter  6  modulates a carrier in accordance with the image signal, and amplifies and supplies its power to the antenna  7  for transmission. After that, it ends processing. 
     The structure of a receiving apparatus for receiving the image signal transmitted by the above-described transmitting apparatus will be described below. 
       FIG. 4  shows a block diagram of an embodiment of a receiving apparatus according to the present invention. 
     In  FIG. 4 , an antenna  20  is used to receive electric waves transmitted by the antenna  7  at the transmitting end. A television (TV) tuner  21  extracts an image signal by extracting a predetermined frequency (broadcasting station) signal from the electric waves received by the antenna  20  and demodulating it, and the TV tuner  21  extracts EPG included in the image signal. 
     A provider-information extractor  22  extracts provider information (provider tag) included in the EPG extracted by the TV tuner  21 , and outputs the obtained provider tag and EPG. 
     A frame memory  23  combines the image signal from the TV tuner  21  and the EPG output from a controller  25 , or selects either one, and outputs it to a cathode-ray tube (CRT)  24  for display. 
     The CRT  24  displays the image signal output from the frame memory  23 . 
     The controller  25  includes: a central processing unit (CPU)  25   a  for controlling other units; a read only memory (ROM)  25   b  in which predetermined programs to be executed by the CPU  25   a  and data are stored; a random access memory (RAM)  25   c  in which, when the CPU  25   a  performs predetermined computation, data and programs which are being used for the computation are stored; and an interface (IF)  25   d  for converting the format of data when the data is transmitted to or received from an external apparatus. 
     An input unit  26  is operated when a user provides a predetermined input (for example, input for selecting a receiving channel). 
     In the above-described embodiment, an amplifier, a speaker, etc. for reproducing a sound signal included in the image signal received by the TV tuner  21  are omitted for a simplified description. 
     The operation of the above-described embodiment will be described below with reference to the flowchart shown in  FIG. 5 . 
       FIG. 5  shows the flowchart, which illustrates a process executed in the controller  25  shown in  FIG. 4 . 
     When the process shown in  FIG. 5  is executed, in step S 10 , the CPU  25   a  in the controller  25  determines whether or not a predetermined input for displaying EPG has been provided from the input unit  26 . If it is determined that the predetermined input has not been provided (NO), the process returns to step S 10 , in which the same processing is repeatedly performed until the predetermined input is provided. If it is determined that the predetermined input has been provided (YES), the process proceeds to step S 11 . 
     In step S 11 , the CPU  25   a  specifies a broadcasting station that provides EPG by referring to the provider tag (e.g., “ASAHI” etc.) extracted by the provider-information extractor  22 . The process proceeds to step S 12 . 
     In step S 12 , the CPU  25   a  extracts from the EPG supplied from the provider-information extractor  22 , program information from the broadcasting station corresponding to the provider tag. 
     It is assumed that the provider tag is “ASAHI”, the broadcast file  6  shown in  FIG. 3  is extracted as extractive program information. Such program information is transmitted for a one day requirement. Accordingly, in step S 12 , a plurality of broadcast files are extracted in addition to the broadcast file  6 . 
     In step S 13 , the CPU  25   a  sets the program information (broadcast file) from the broadcasting station corresponding to the provider tag extracted in step S 12  in the frame memory  23  in its top row in the order of time. 
     In step S 14 , the CPU  25   a  sets other program information (program information from broadcasting stations excluding the broadcasting station corresponding to the provider tag) in the frame memory  23  in the order of channels. 
       FIG. 6  shows an example of an image displayed on the CRT  25  as a result of processing in steps S 13  and S 14 . In this example, the programs corresponding to the provider tag “ASAHI”, namely, “SUIYO SUSPENSE”, “RYORI”, and “SASURAI KEIJI KANJO-HEN” are displayed in the top row, with them magnified and the background color changed. Under the programs, “NE (NEWS)” and “ASAGA MAIRIMASHITA” are displayed. Under them, programs from broadcasters “KYOIKU” and “NIPPON” are displayed in a format identical to that in the above case. 
     In the case where the above-described processing (display alteration in accordance with the provider tag) is not performed, an image as shown in  FIG. 7  is displayed. In this image, program information from broadcasting stations is displayed in the order of the following channels: “SOGO” (channel 1), “KYOIKU” (channel 3), “NIPPON” (channel 4), “TOKYO” (channel 6), “FUJI” (channel 8), and “ASAHI” (channel 10). In the same format, information on all broadcasting stations is displayed. 
     Returning to the flowchart shown in  FIG. 5 , in step S 15 , the CPU  25   a  determines whether or not a predetermined input for ending EPG display is provided from the input unit  26 . If it is determined that the predetermined input has not been provided (No), the process returns to step S 15 , in which the same processing is repeatedly performed. If it is determined that the predetermined input has been provided (YES), the process ends. 
     According to the above-described embodiment, a transmitting apparatus adds to an image signal, provider information indicating broadcast stations that provide EPG, and a receiving apparatus displays in a top row, program information from the broadcast station corresponding to the provider information so that the program information is emphasized. Thus, a possibility in which a user watches the programs from the broadcasting station can be increased. 
     According to the above-described embodiment, part of the program information is displayed as shown in  FIG. 6 . However, needless to say, similarly to the case shown in  FIG. 7 , information on the whole of the program information may be displayed. 
     In the case where the number of broadcasting stations providing EPG is two, two type of provider information are transmitted. In this case, for example, as shown in  FIG. 8 , program information corresponding to the two broadcasting stations may be displayed in top rows. 
       FIG. 9  shows a block diagram of a second embodiment of a receiving apparatus according to the present invention. In  FIG. 9 , components corresponding to those shown in  FIG. 4  are denoted by identical reference numerals for omitting descriptions. 
     Compared with the embodiment shown in  FIG. 4 , the provider-information extractor  22  is excluded in the second embodiment. In a ROM  25   b  in a controller  25 , a table on the correspondence between frequencies and channel identifications (Ids) is stored as shown in  FIG. 11 . The structures of other components are identical to those shown in  FIG. 4 . 
     The operation of the receiving apparatus shown in  FIG. 9  will be described below, with reference to the flowchart shown in  FIG. 10 . 
       FIG. 10  shows a flowchart illustrating a process executed in the controller  25  shown in  FIG. 9 . 
     When the process is executed, in step S 20 , a CPU  25   a  determines whether or not a predetermined input for displaying EPG has been provided from an input unit  26 . If it is determined that the predetermined input has not been provided (NO), the process returns to step S 20 , in which the same processing is repeatedly performed until the predetermined input is provided. If it is determined that the predetermined input has been input (YES), the process proceeds to step S 21 . 
     In step S 21 , the CPU  25   a  acquires the frequency of a signal that is being received by a TV tuner  21 . The process proceeds to step S 22 , in which the broadcasting station ID corresponding to the acquired frequency is retrieved from the ROM  25   b.    
       FIG. 11  shows the table indicating the correspondence between frequencies and broadcasting station (channel) Ids. In the table, a frequency of 90 to 96 MHz corresponds to broadcaster “SOGO”, a frequency of 102 to 108 MHz corresponds to broadcaster “KYOIKU”, a frequency of 170 to 176 MHz corresponds to broadcaster “NIPPON”, a frequency of 192 to 198 MHz corresponds to broadcaster “FUJI”, and a frequency of 204 to 210 MHz corresponds to broadcaster “ASAHI”. 
     In the case where the receiving frequency of the TV tuner  21  is, for example, 207 MHz, the CPU  25   a  acquires “ASAHI” as a broadcasting station (channel) ID. 
     In step S 23 , the CPU  25   a  extracts the program information corresponding to the broadcasting station ID acquired in step S 22  from EPG data supplied from the TV tuner  21 . The process proceeds to step S 24 . 
     In step S 24 , the CPU  25   a  enlarges the program information extracted in step S 23 , and writes it in a predetermined region of a frame memory  23 , whereby it can be displayed in the top row on a CRT  24 . The process proceeds to step S 25 . 
     In step S 25 , the CPU  25   a  causes the CRT  24  to display additional information (not shown) included in the EPG extracted by the TV tuner  21  in the second top row on the CRT  24 . The additional information relates to a program title, program contents, or a cast. 
     The process proceeds to step S 26 , in which information on other programs (program information from broadcasting stations excluding the broadcasting station being received) is displayed on the CRT  24  in the order of channels. 
       FIG. 12  shows an example of an image displayed on the CRT  24  as a result of processing in steps S 24  to S 26 . In this example the program information corresponding to broadcaster “ASAHI”, which is program information corresponding to the broadcasting station being received, is displayed in the top row on the screen. In addition, under program names (“SUIYO SUSPENSE”, “RYORI”, and “SASURAI KEIJI KANJO-HEN”), program titles (“MIKKAINO SATSUJIN JIKEN” and “SHISANKA KIETA”), program contents (“KANINO MUSHI”), a cast (NAKAO KIYO, MORIMOTO REO, MATSUSHIMA SHIN-ICHI, YOSHIDA KAZUKO, NISHIDA MAKOTO), and so forth, are displayed. Under broadcaster “ASAHI”, program information from other broadcasters (or channels): “SOGO”, “KYOIKU”, and “NIPPON” are sequentially displayed. 
     According to the above-described embodiment, program information from one broadcasting station being received is displayed in the top row, which enables the user to instantly refer to other programs from the broadcasting station. 
       FIG. 13  shows a block diagram of a third embodiment of a receiving apparatus according to the present invention. Components in  FIG. 3  corresponding to those shown in  FIG. 4  are denoted by identical reference numerals for omitting descriptions. 
     Compared with the first embodiment shown in  FIG. 4 , in the third embodiment shown in  FIG. 13 , the provider-information extractor  22  is excluded and a priority-station information generator  30  is additionally provided. The structures of other components are identical to those shown in  FIG. 4 . 
     The priority-station information generator  30  is used to generate a tag (e.g., “ASAHI”) indicating a broadcasting station in cooperation with a manufacturer that produces or sells the receiving apparatus. 
     The operation of the receiving apparatus according to the third embodiment will be described below, with reference to the flowchart shown in  FIG. 14 . 
     When the process is executed, in step S 40 , a CPU  25   a  in a controller  25  determines whether or not a predetermined input for displaying EPG has been provided from an input unit  26 . If it is determined that the predetermined input has not been provided (NO), the process returns to step S 40 , in which the same processing is repeatedly performed. If it is determined that the predetermined input has been provided (YES), the process proceeds to step S 41 . 
     In step S 41 , the CPU  25   a  acquires the priority station tag output from the priority-station information generator  30 . The process proceeds to step S 42 , in which the CPU  25   a  extracts program information corresponding to the priority station tag from EPG data output from the TV tuner  21 . 
     In step S 43 , the CPU  25   a  enlarges the program information extracted in step S 42  and writes it in a predetermined region of a frame memory  23 , whereby it can be emphatically displayed in the top row on a CRT  24 . In step S 44 , the CPU  25   a  uses the CRT  24  to display other program information in the order of channels. 
     Here, when it is assumed that broadcaster “ASAHI” is in cooperation with the manufacturer producing the receiving apparatus and that the priority-station information generator  30  generates “ASAHI” as a priority station tag, the image shown in  FIG. 6  is displayed on the CRT  24  as a result of display processing in steps S 43  and S 44 . Accordingly, a possibility in which programs from the broadcasting station in cooperation with the manufacturer producing the receiving apparatus are watched can be increased. 
     In the foregoing embodiments, an example of analog terrestrial broadcasting has been described. However, the present invention is not limited to such a case but, needless to say, it may be applied to, for example, satellite broadcasting, digital broadcasting, or cable television. 
     In this specification types of the transmission medium include not only information recording media such as a floppy disc and a CD-ROM but also network transmission media such as the Internet and a digital broadcasting satellite.
A receiving apparatus receives an image signal transmitted from a transmitting end. In the receiving apparatus, the received image signal is output to a display. Electronic program guide information (EPG) added to the received image signal is extracted. The display format of the EPG is altered in accordance with predetermined information. And, the altered EPG is output to the display. A transmitting apparatus transmits an image signal to a receiving end. In the transmitting apparatus, the image signal, EPG, information representing a broadcasting station providing the EPG are generated. The EPG and the information representing the broadcasting station are added to the image signal. And, a signal formed by adding the EPG and the information representing the broadcasting station to the image signal is transmitted to the receiving end.