EP1032146A2

EP1032146A2 - Broadcast system and terminal for receiving and reproducing broadcast signals, comprising a download unit

Info

Publication number: EP1032146A2
Application number: EP20000301401
Authority: EP
Inventors: Eiji Kawai
Original assignee: Sony Computer Entertainment Inc
Current assignee: Sony Interactive Entertainment Inc
Priority date: 1999-02-24
Filing date: 2000-02-23
Publication date: 2000-08-30
Also published as: EP1032146A3; JP2000244426A

Abstract

A broadcast system for allowing a receiving/reproducing terminal to reproduce moving pictures in real time even if utilizing a communication infrastructure having a low transmission data rate is disclosed. Background data or outline data is stored in a data memory of the receiving/reproducing terminal in advance by a download system. Then, by utilizing a communication infrastructure having a low transmission data rate, such as a beeper system, a plurality of parts data are sequentially sent. The receiving/reproducing terminal receives the parts data, and simultaneously reads the background data or the outline data from the data memory in real time. Parts images represented by the parts data are sequentially superimposed on a background image or an outline image corresponding to the background data or the outline data, respectively, and the resulting superimposed image is displayed as an overall moving picture.

Description

BACKGROUND OF THE INVENTION

1. FIELD OF THE INVENTION

The present invention relates generally to a broadcast system, and more specifically to a receiving/reproducing terminal which utilizes a transmission system having a relatively low data transmission rate.

2. DESCRIPTION OF RELATED ART

Broadcast systems for transmitting high-quality images and sound to viewers in real time, such as, terrestrial television broadcast systems, satellite broadcast systems implemented by broadcasting satellite (BS) or communications satellite (CS), cable television (CATV) systems implemented by cable networks, and so on, have been put into widespread practical use.
However, in the above types of broadcast systems, the cost for starting a broadcast business and producing content and broadcasting programs is typically quite high. Furthermore, a large-scale transmitting system is usually required. This imposes a heavy restriction on the implementation of broadcast business, and often requires obtaining legal authorization. Additionally, a relatively large antenna and hardware are typically required for selectively receiving high-quality images and sound, and for reproducing them by using a display unit and a sound output unit. It is very difficult to integrate such a large antenna and hardware into a portable receiving/reproducing terminal. Accordingly, in general, receiving/reproducing apparatuses for receiving and reproducing high-quality images and sound must be installed indoors.
Portable machines, such as cellular telephones, personal handyphone system (PHS) terminals, and portable information communication devices (i.e., personal digital assistants (PDA), which may sometimes include cellular telephones and PHS terminals), are coming into widespread use. Additionally, information other than sound, such as electronic mail, is actively communicated by utilizing the infrastructure of the above-mentioned portable machines. Machines that can be used as a broadcasting infrastructure (system), such as beepers, are also available.
In the machines that exhibit advantageous portability, such as the beeper system described above, the data rate is typically too low to receive and reproduce high quality images with sound. Apart from sound data, such portable machines are generally used only for transmitting and receiving character-based (textual) information.
In the following description, the term "content" means various information, such as pictures, images (both moving pictures and still images), sound, characters, numerical data, and so on, and includes programs reproduced by television receivers and radio receivers, commercials (CM), magazines, and newspapers.

SUMMARY OF THE INVENTION

In view of the above background, it is an object of embodiments of the present invention to provide a broadcast system and a receiving/reproducing terminal that cyclically or non-cyclically reproduces content (for example, images) in real time for a certain period of time by utilizing a system (infrastructure) having a relatively low data rate.
In order to achieve the above object, according to one aspect of the present invention, there is provided a broadcast system for transmitting and receiving content as data in real time. The broadcast system includes a download unit, a transmitting apparatus, and a receiving/reproducing terminal. The download unit transmits time-invariant content data in advance, and the transmitting apparatus transmits time-varying content data as radio waves. The receiving/reproducing terminal includes a storage device, and the time-invariant content data transmitted from the download unit is stored in the storage device in advance. Upon receiving the time-varying content data from the transmitting apparatus, the receiving/reproducing terminal reproduces the content in real time from the time-invariant content data and the time-varying content data.
With this arrangement, when the time-varying content data is received from the transmitting apparatus, the content (for example, a high-quality image and sound) can be reproduced in real time for a certain period of time from the time-invariant content data and the time-varying content data.
According to another aspect of the present invention, there is provided a broadcast system for transmitting and receiving content as data in real time. The broadcast system includes a download unit, a transmitting apparatus, and a receiving/reproducing terminal. The download unit transmits content data in advance, and the transmitting apparatus transmits reproducing command data as radio waves. The receiving/reproducing terminal includes a storage device, and the content data transmitted from the download unit is stored in the storage device in advance. Upon receiving the reproducing command data from the transmitting apparatus, the receiving/reproducing terminal reproduces the content in real time from the downloaded content data based on the reproducing command data.
With this configuration, when the reproducing command data is received from the transmitting apparatus, the content (for example, a high-quality image and sound) can be reproduced in real time from the downloaded content data based on the reproducing command data. In this case, the content data to be downloaded in advance may include time-varying content data and time-invariant content data.
According to still another aspect of the present invention, there is provided a broadcast system for transmitting and receiving content as data in real time. The broadcast system includes a transmitting apparatus, and a receiving/reproducing terminal. The transmitting apparatus first transmits time-invariant content data as radio waves in advance, and then transmits time-varying content data as radio waves later. The receiving/reproducing terminal includes a storage device, and the time-invariant content data transmitted from the transmitting apparatus is stored in the storage device in advance. Upon receiving the time-varying content data as the radio waves from the transmitting apparatus, the receiving/reproducing terminal reproduces the content in real time by combining the time-invariant content data and the time-varying content data.
With this configuration, when the time-varying content data is received from the transmitting apparatus, the content (for example, a high-quality image and sound) can be reproduced in real time from the time-invariant content data and the time-varying content data without the need for a download unit.
According to a further aspect of the present invention, there is provided a broadcast system for transmitting and receiving content as data in real time. The broadcast system includes a transmitting apparatus and a receiving/reproducing terminal. The transmitting apparatus transmits time-invariant content data and time-varying content data as radio waves in advance, and also transmits reproducing command data. The receiving/reproducing terminal includes a storage device. The time-invariant content data and the time-varying content data transmitted from the transmitting apparatus are stored in the storage device in advance. Upon receiving the reproducing command data from the transmitting apparatus, the receiving/reproducing terminal reproduces the content in real time from the time-invariant content data and the time-varying content data based on the reproducing command data.
With this arrangement, when the reproducing command data is received from the transmitting apparatus, the content (for example, a high-quality image and sound) can be reproduced in real time from the time-invariant content data and the time-varying content data without the need for a download unit.
According to any one of the aspects of the present invention, the time-invariant content data may be background image data or outline image data, and the time-varying content data may be image data of an image to be superimposed on a background image corresponding to the background image data or an outline image corresponding to the outline image data. It is thus possible to reproduce high data-rate images, such as moving pictures, on the receiving/reproducing terminal, for example, for a certain period of time.
According to a yet further aspect of the present invention, there is provided a receiving/reproducing terminal including a data input unit for inputting content data, a data storage unit for storing the content data, a data reproduction unit for reproducing the content data, and a control unit for controlling the data input unit, the data storage unit, and the data reproduction unit. The control unit stores time-invariant content data supplied from an external source via the data input unit in the data storage unit in advance. Upon receiving time-varying content data from the external source via the data input unit, the control unit reproduces the content from the time-varying content data and the time-invariant content data in real time by using the data reproduction unit.
With this configuration, when the time-varying content data is received from an external source, the content (for example, a high-quality image and sound) can be reproduced in real time from the time-invariant content data and the time-varying content data.
According to a further aspect of the present invention, there is provided a receiving/reproducing terminal including a data input unit for inputting content data, a data storage unit for storing the content data, a data reproduction unit for reproducing the content data, and a control unit for controlling the data input unit, the data storage unit, and the data reproduction unit. The control unit stores time-invariant content data and time-varying content data supplied from an external source via the data input unit in the data storage unit in advance. Upon receiving reproducing command data from the external source via the data input unit, the control unit reproduces the content from the time-varying content data and the time-invariant content data in real time based on the reproducing command data by using the data reproduction unit.
With the above arrangement, when the reproducing command data is received from an external source, the content (for example, a high-quality image and sound) can be reproduced in real time from the time-invariant content data and the time-varying content data. The time-invariant content data may be background image data or outline image data, and the time-varying content data may be image data of an image to be superimposed on a background image corresponding to the background image data or an outline image corresponding to the outline image data. Thus, high data-rate images, such as moving pictures, can be reproduced on the receiving/reproducing terminal, for a certain period of time.
Other objects, features, and advantages of the present invention will be apparent from the accompanying drawings and from the detailed description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which:
Figure 1 is a diagram illustrating the configuration of a broadcast system incorporating an embodiment of the present invention;
Figure 2 is a plan view illustrating the external configuration of a receiving/reproducing terminal, according to one embodiment of the present invention;
Figure 3 is a block diagram illustrating the electrical configuration of a receiving/reproducing terminal, according to one embodiment of the present invention;
Figure 4 is a perspective view illustrating a download system, according to one embodiment of the present invention;
Figure 5 is a block diagram illustrating the electrical configuration of the download system, according to one embodiment of the present invention;
Figure 6 is a block diagram illustrating the electrical configuration of an operation unit, according to one embodiment of the present invention;
Figure 7 is a flow chart illustrating the operation of processing received data, according to an embodiment of the present invention;
Figure 8 illustrates an example of a time-invariant image corresponding to outline data;
Figure 9 is a time chart diagram illustrating an example of time-varying images corresponding to data representing certain parts of a human face;
Figure 10 illustrates the reproduction of a superimposed image as a moving picture for an exemplary image;
Figure 11 illustrates a second example of a time-invariant image corresponding to outline data;
Figure 12 illustrates an example of time-varying images corresponding to data representing weather symbols;
Figure 13 illustrates the reproduction of a superimposed image for a second exemplary image;
Figure 14 illustrates an example of modifications made to the broadcast system, for an alternative embodiment of the present invention;
Figure 15 illustrates another example of modifications made to the broadcast system, for an alternative embodiment of the present invention;
Figure 16 is a diagram illustrating an example of a program schedule with divided data rates according to another embodiment of the present invention;
Figure 17 is a flow chart illustrating the receiving and reproducing process performed by a receiving/reproducing terminal, according to one embodiment of the present invention; and
Figure 18 is a diagram illustrating a sequence of outputting high data-rate data, such as images, in real time for a certain period of time by utilizing a low data-rate transmitting infrastructure.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A broadcast system and a receiving/reproducing terminal for reproducing broadcast content in real time is described. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be evident, however, to one of ordinary skill in the art, that the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form to facilitate explanation. The description of preferred embodiments is not intended to limit the scope of the claims appended hereto.
Referring to the configuration of a broadcast system 10 according to an embodiment of the present invention shown in Figure 1, a known public-line network 12 and a beeper system 14 are used as communication infrastructures. Although, in practice, the beeper system 14 includes a central station and a base station, a transmitting apparatus (also referred to as the "transmitting station") 18 having a transmitting antenna 16 serves as both the central station and the base station for simple representation.
One or more portable receiving/reproducing terminals 20A, 20B, and 20C (indicated as element 20 when referring to each terminal individually) having different addresses are distributed within the zone or area in which radio waves emitted from the transmitting antenna 16 extend. If the receiving/reproducing terminals 20A, 20B, and 20C are used in a manner similar to a television receiver or a radio receiver, the provision of different addresses is not necessary.
The beeper system 14 for use in this embodiment is basically a character-based communication infrastructure having a comparatively low data rate (transmission capacity), such as 6.4 kbps (the FLEX time diversity (FLEX-TD) method). In this embodiment, however, by utilizing the beeper system 14, a system is constructed in which image information including moving pictures are reproducible in real time by the receiving/reproducing terminal 20, which is configured very simply and exhibits advantageous portability.
The transmitting apparatus 18 for use in the beeper system 14 is connected to the public-line network 12. A terminal (computer terminal) 22 of a content provider for producing information-type content, and a terminal (computer terminal) 24 of another content provider for producing entertainment-type content are also connected to the public-line network 12.
The information-type content may include content such as, news, weather forecasts, stock broadcasting, messages, and similar content. The entertainment-type content could include various different types of entertainment such as, talk shows and games, such as Igo (Japanese game), Shogi (Japanese chess), and other such content.
Content data transmitted from the content-provider terminal 22 is supplied to an editing terminal (also referred to as a "program editing terminal" or an "editing computer") 26 disposed within the transmitting apparatus 18 via the public-line network 12. Content data transmitted from the content-provider terminal 24 is also supplied to the program editing terminal 26 via the public-line network 12.
Such content data is edited by the program editing terminal 26 and is transmitted as radio waves via a transmitter 28 and the transmitting antenna 16. In this embodiment, as stated above, the transmission data rate is 6.4 kbps according to the FLEX-TD method, which is typically employed for beepers. The term "data rate" is also referred to as the "transmission capacity" or the "bandwidth".
Figure 2 is a plan view illustrating the receiving/reproducing terminal 20. Although various types of beeper receivers may be used as the receiving/reproducing terminal 20, a specific terminal is illustrated for this embodiment.
Figure 3 is a block diagram illustrating the basic configuration of the electrical circuit of the receiving/reproducing terminal 20 for use in the broadcast system 10.
The external configuration of the receiving/reproducing terminal 20 for one embodiment of the present invention, is illustrated in Figure 2. A lid member 79 having operation keys 78 formed of a canceling key 78Ca, a cross key 78Cr, a setting key 78D, and a mode switching key 78M (which are discussed in detail later), a liquid crystal display (LCD) device 74, and a flexible antenna 50 are attached to a casing 75 having a flat bottom and formed generally in an oval shape. The receiving/reproducing terminal 20 is flat and thin-walled, and is approximately the same size or smaller than the palm of a person's hand as viewed from the front side.
The receiving/reproducing terminal 20 includes, as shown in Figure 3, a control unit 40, such as a microcomputer. A central processing unit (CPU) 44 for use in the control unit 40 controls the entire system of the receiving/reproducing terminal 20. The individual blocks are connected to a system bus 46, which is managed by the CPU 44. The CPU 44 includes a read only memory (ROM) for storing a control program (such as a kernel), a random access memory (RAM) serving as a temporary storage device and used for a work area, and a timer (real time clock) which serves as a counting device.
The receiving/reproducing terminal 20 has two communication input paths. A first communication input path is formed of a receiving antenna 50, a radio frequency (RF) processor 52, a decoder 54, and a serial-to-parallel interface (SPI) 56 for converting serial signals into parallel signals. In this case, radio waves including content data transmitted as broadcast waves from the transmitting apparatus 18 shown in Figure 1 are received by the receiving antenna 50. After the RF signal is converted into an intermediate frequency (IF) signal by the RF processor 52, the IF signal is demodulated and is decoded into serial data by the decoder 54. The serial data is then converted into parallel data by the serial-to-parallel interface 56 and is output to the system bus 46.
A second communication input path enables the receiving/reproducing terminal 20 to communicate with external systems, and is formed of a physical connector 58 for connecting the receiving/reproducing terminal 20 to an entertainment machine, which serves as a main unit (as described later), and a serial-to-parallel interface 59. In this case, serial data is transmitted from the entertainment machine and is converted into parallel data by the serial-to-parallel interface 59, and the parallel data is then output to the system bus 46.
A data memory (storage device) 62 having, for example, a 16 MB capacity, which serves as an external storage device, is connected to the system bus 46 via a corresponding memory interface 60.
A digital-to-analog converter (DAC) 64 for converting a digital sound signal into an analog signal is also connected to the system bus 46, and the converted analog signal is output from a speaker 68, which serves as a sound output device, via an amplifier 66.
A graphic display controller (GDC)/decoder 70, which serves as both an image processor and a decoder, is connected to the system bus 46. Further, a liquid crystal display (LCD) 74, such as a thin-film transistor (TFT) color liquid crystal display device, is connected to the system bus 46 via a liquid crystal display controller (LCDC) 72. The operation keys 78 are also connected to the system bus 46 via a switch interface 76.
As stated above with reference to Figure 2, the operation keys 78 are formed of the cross key 78Cr for selecting a received broadcast channel and selecting characters, the setting key 78D, the canceling key 78Ca, and the mode switching key 78M for switching between a broadcast receiving mode and a beeper mode. The above-mentioned keys may have complex functions, and one may also serve as a power key (on/off key). However, the power key is preferably provided separately from the above keys.
Although a specific configuration and schematic of a receiving/reproducing terminal was illustrated in Figures 2 and 3, it should be noted that various different configurations of receiving/reproducing terminals may be utilized in accordance with embodiments of the present invention.
Figure 4 is a perspective view illustrating a download system 100 to which the receiving/reproducing terminal 20 is connected when downloading is performed. In one embodiment of the present invention, the download system 100 is formed of the several elements. An entertainment machine 102 serves as a main unit of the receiving/reproducing terminal 20. An operation unit (controller) 108 is detachably attached to a lower inserting portion 106A or 106B provided for a slot 104A or 104B, respectively. The receiving/reproducing terminal 20 is detachably attached to an upper inserting portion 110A or 110B provided for the slot 104A or 104B, respectively, by opening the lid member 79. A monitor 164, such as a television receiver, receives video output signals and sound output signals from the entertainment machine 102. A memory card for recording certain information, such as a current setting of a game, may be inserted into the upper inserting portion 110A or 110B of the entertainment machine 102. Such a memory card is not shown to avoid obscuring the illustration.
The entertainment machine 102 is formed of a disc loading portion 114 for loading an optical disc, such as a compact disc-read only memory (CD-ROM) that serves as a recording medium, a reset switch 116, a power switch 118, a disc operating switch 120 for operating the loading of the optical disc, and two slots 104A and 104B.
The operation unit 108 to be attached to the entertainment machine 102 includes first and second operating portions 121 and 122, a left button 123L, a right button 123R, a start button 124, a selection button 125, analog operating portions 131 and 132 (which can be manually operated), a mode-selecting switch 133 for selecting the operation modes of the analog operating portions 131 and 132, and an indicator 134 for indicating the selected operation mode. For convenience, the elements other than the indicator 134 will be referred to as an "operating key unit" 135.
In the entertainment machine 102, a program recorded on an optical disc is read by using the disc loading portion 114. A program, such as a game, can be executed according to the image display and the sound output of the monitor 164 in response to an instruction from a user (for example, a game player) through the operation unit 108.
Desired content data is selected by using the operation unit 108 while reproducing content (image) 200 recorded on an optical disc corresponding to time-invariant content data. The selected content data is then read by using the disc loading portion 114 and is stored (downloaded) in the data memory 62, which serves as a storage device of the receiving/reproducing terminal 20. The time-invariant content data is a still image, which does not change for a certain period of time on the monitor 164. Such time-invariant data could be data having a relatively large capacity, such as background image data or outline image data.
Desired content data to be downloaded into the data memory 62 of the receiving/reproducing terminal 20 may include not only time-invariant content data, but also time-varying content data. Time-varying content data may be data such as a sprite image to be superimposed on a background image or an outline image corresponding to the time-invariant content data, such as background image data or outline image data. The resulting superimposed image may then be displayed as a moving picture. That is, the time-varying content data is image data that is independent of the background image or the outline image. By continuously superimposing sprite images on the background image or the outline image, moving pictures can be reproduced. Specific examples of the individual images are discussed in detail later.
Although a specific configuration of a download unit was illustrated in Figure 4, it should be noted that various different configurations of download units and specific implementations may be utilized in accordance with embodiments of the present invention.
Figure 5 is a schematic block diagram illustrating the electrical configuration of the download system 100. Figure 6 is a schematic block diagram illustrating the electrical configuration of the operation unit 108.
Referring to Figure 5, the entertainment machine 102 for use in the download system 100 is formed of several elements. A control system 150 includes a central processing unit (CPU) 151 and peripheral devices. A graphic system 152 has a graphic processing unit (GPU) for drawing images in a frame buffer (not shown). A sound system 154 has a sound processing unit (SPU) for generating music and surround sound effects. An optical disc controller 158 controls optical discs on which application programs and data are recorded. A communication controller 160 controls the input and output of data into and from the receiving/reproducing terminal 20 and a memory card (not shown), which stores instructions from a user through the operation unit 108 and the current setting of a game. The above-described elements are connected to a bus 162.
For the embodiment illustrated in Figure 5, the control system 150 includes CPU 151, a peripheral-device controller for performing interrupt control and direct memory access (DMA) control. The control system 150 also includes a main memory (main storage device) formed of RAM, and ROM for storing an operating system that manages the main memory, the graphic system 152, the sound system 154, and other elements. When the entertainment machine 102 is powered on, the CPU 151 of the control system 150 runs the operating system stored in the ROM so as to control the graphic system 152, the sound system 154, and so on.
For example, by running a program, such as a game, the CPU 151 controls the graphic system 152 and sound system 154 in response to an input operation from the user, thereby displaying images on the monitor 164 and generating music and surround sound effects.
In one embodiment of the present invention, the graphic system 152 has a geometry transfer engine (GTE) for performing coordinate transforms, a graphic processing unit for drawing an image according to a drawing command from the CPU 151, a frame buffer for storing the image drawn by the graphic processing unit, and an image decoder for decoding the compressed and coded image data by orthogonal transforms (such as a discrete cosine transforms).
The sound system 154 includes a sound processing unit for generating music and surround sound effects in response to an instruction from the CPU 151, a sound buffer for recording waveform data generated by using the sound processing unit. Also included is a speaker for outputting the music and surround sound effects generated by the sound processing unit.
A video output signal of the graphic system 152 and a sound output signal of the sound system 154 are supplied to the monitor 164. The image is reproduced on the screen of the monitor 164, and the sound is reproduced from the speaker of the monitor 164.
The optical disc controller 158 has an optical disc device for reading a program or data recorded on an optical disc 156, a decoder for decoding the program or data recorded with error correction code (ECC). The optical disc controller 158 also includes a buffer for speeding up the read operation of data from the optical disc 156 by temporarily storing the data from the optical disc. A sub-CPU may be connected to the decoder. The communication controller 160 controls communications between the receiving/reproducing terminal 20 and the operation unit 108, and the CPU 151, via the bus 162.
Referring to Figure 6, in one embodiment of the present invention, the operation unit 108 has a microcomputer 170 including a CPU, a ROM, and a RAM, which serves as an overall control unit. The microcomputer 170 is connected to the operation key unit 135 through an interface 172. The microcomputer 170 is also connected to a connector 176 through another interface 174 and a cable. For the system illustrated in Figure 4, the connector 176 is coupled to the slot 104B.
The operation of the broadcast system 10 and the download system 100 basically constructed as described above, is discussed below with reference to the flowchart of Figure 7.
In step 701, time-invariant content data is downloaded from the entertainment machine 102 to the receiving/reproducing terminal 20. To execute the processing in step 701, the receiving/reproducing terminal 20 is first attached to the entertainment machine 102 (as shown in Figures 4 and 5) before receiving and reproducing a broadcast in real time through radio waves transmitted from the transmitting apparatus 18. Then, the optical disc 156 for storing the above-described time-invariant content data having a comparatively large capacity is loaded into the entertainment machine 102, thereby reproducing the content (image) 200 on the screen of the monitor 164.
Figure 8 illustrates the image 200 based on human outline data Da1 as an example of the time-invariant content data displayed on the monitor 164. For this embodiment, the ID code may be indicated by ID1.
By selecting the desired human outline data Da1 from the various images 200 displayed on the monitor 164 by using the operation unit 108, the outline data Da1 representing the image 200 is stored together with the ID code (e.g., ID1) in the data memory 62. This data is provided via the optical disc controller 158, the bus 162, the communication controller 160 of the entertainment machine 102, the connector 58, the SPI 59, the system bus 46, and the memory interface 60 of the receiving/reproducing terminal 20.
In the example illustrated in Figure 8, the human outline data Da1 may be two-dimensional graphic data, three-dimensional graphic data, data representing a person's upper body, or a natural-image data, such as a portrait picture. The human outline data Da1 to be stored in the data memory 62 may include only one person or many people. If the human outline data Da1 includes many people, ID codes are separately provided. The outline data Da is not limited to humans, and many objects can be represented.
Next, the receiving/reproducing terminal 20 loaded with the outline data Da1 corresponding to the ID code ID1 in the data memory 62 is detached from the entertainment machine 102. By turning on the power switch, the receiving/reproducing terminal 20 is ready to receive broadcasts.
Referring back to Figure 7, in step 702, the receiving/reproducing terminal 20 is ready to receive broadcasts while being carried or used indoors separately from the entertainment machine 102, as shown in Figure 1. Time-varying content data with an appropriate ID code output from the program editing terminal 26 based on a program schedule of the transmitting apparatus 18 is transmitted as radio waves via the transmitter 28 and the transmitting antenna 16. This data is then received by the receiving/reproducing terminal 20 via the receiving antenna 50.
Figure 9 illustrates several examples of time-varying content data Db1 (which is also referred to as "parts data") with ID code ID1. This may be data that is edited in the program editing terminal 26 and is output from the terminal 26. As shown in Figure 9, at time t1 corresponding to time Ta, a pair of image data E1 and M1 representing eye and mouth shapes for image and sound data indicating the shape of a mouth saying "a", are sent as the content data Db1. The image and sound data M1 contains sound data synchronized with the image data.
After time t1, parts data Db1 (E2, M2), Db1 (E3, M3), Db1 (E4, M4), Db1 (E5, M5), and so on, are transmitted at times t2, t3, t4, t5, etc., respectively. The data M2, M3, M4, and M5 represent the shapes of the mouth issuing sounds "i", "u", "e" ,and "o".
The radio wave including the time-varying content data with the ID code is received by the receiving antenna 50 of the receiving/reproducing terminal 20. After the RF signal is converted into an IF signal by the RF processor 52, the IF signal is demodulated and is decoded into serial data by the decoder 54, and is converted into parallel data by the SPI 56. The parallel data is then output to the system bus 46.
In this case, in step 703 of Figure 7, the type of ID code of the time-varying content data Db is decoded by the decoder 54. Also in step 703, the CPU 44 determines whether the decoded ID code matches the desired ID code (e.g., ID code ID1) of the image 200 stored in the data memory 62. If the outcome is no, steps 702 and 703 are repeated until the desired ID code ID 1 is detected (i.e., the ID code decoded by the decoder 54 matches the desired ID code ID1).
If the result of step 703 is yes, the data reading processing is executed in step 704, and the data synthesizing (superimposing)/reproducing processing is executed in step 705. The ID code may be decoded by the CPU 44 rather than the decoder 54. According to the process of steps 704 and 705, the program of the content data Db1 corresponding to the ID code ID1 is reproduced in real time.
More specifically, in step 704, the human outline data Da1 representing the image 200 illustrated in Figure 8 is read from the data memory 62 and is sent to the GDC/decoder 70 via the memory interface 60 and the system bus 46. The GDC/decoder 70 performs image processing by superimposing (combining) the time-varying content data Db with the ID code ID1, which is received in real time at times t1, t2, t3, t4, and t5 illustrated in Figure 9, on (with) the human outline data Da1. The GDC/decoder 70 then displays a moving picture, which reflects the graphic display and the high-efficiency encoding technique, in real time on the LCD 74 via the LCDC 72. In other words, the GDC/decoder 70 displays the moving picture on the LCD 74 in synchronization with the receiving of the parts data Db1. Sound is also reproduced and output via the DAC 64, the amplifier 66, and the speaker 68 in synchronization with the receiving of the parts data Db1.
For example, at time t1, the parts data Db1 (E1, M1) is combined with the outline data Da1 corresponding to the ID code ID1. In this manner, the image corresponding to the parts data Db1 (E1, M1) is superimposed on the predetermined position of the outline image corresponding to the outline data Da1. As a result, the human character issuing sound "a" is reproduced on the LCD 74. Subsequently, at times t2 to t5, the eye expression of the human character is changed, and the shape of the mouth is also changed in the order of "i", "u", "e", and "o", respectively.
Figure 10 illustrates a reproduced image 202 as the reproduced content at time t3. More specifically, the parts data Db1 (E3, M3) is combined with the outline data Da1 corresponding to the ID code ID1. In other words, parts images 203 and 205 corresponding to the parts data Db1 (E3, M3) are superimposed on predetermined positions of the outline image 200 corresponding to the outline data Da1. As a consequence, the human character 202 issuing sound "u" is reproduced on the LCD 74. The image corresponding to the data E3 is a right-eye image, and by mirror-inverting the data E3 by the GDC/decoder 70, a left-eye image 203A is created. An image including both eyes may be transmitted as the data E, and the data E1 (for example, the right eye) and the data E4 (for example, the left eye) may be combined to make the character wink. In this case, data indicating the positions at which the parts data E (E = E1, E2, and so on) and the parts data M (M = M1, M2, and so on) are to be superimposed on the outline data 200 may be downloaded together with the outline data Da1. Alternatively, the position indicating data may be sent every time the parts data Db1 is transmitted, i.e., every time each of data Db1 (E1, M1), Db1 (E2, M2), Db1 (E3, M3), Db1 (E4, M4), and Db1 (E5, M5) is transmitted. Normally, the position data is sent every time the parts data Db1 is transmitted.
In this manner, by reproducing the image in synchronization with the sound, the reproduced character image 202 on the LCD 74 appears to speak while changing its expression. Instead of outputting the sound in synchronization with the shape of the mouth, characters (letters) may be output, which is referred to as the "superimpose" technique. This enables the user to operate the receiving/reproducing terminal 20 even when the user is not by himself/herself, such as in a train.
Thereafter, the process from steps 702 to 705 is repeated. That is, the parts data Db1 corresponding to the ID code ID1 is transmitted from the transmitting apparatus 18 to the receiving/reproducing terminal 20 periodically, for example, every hour. Thus, information-type content, such as news, weather forecasts, traffic information, and meteorological information, can be reproduced in real time on the LCD 74 according to the image 200. In this case, the image 200 may be a character 202 represented by the synthesized data (data Da1 + Db1).
Such a technique can also be used to reproduce other content, such as weather reports. To reproduce an image of a weather forecast on its own, or together with the character image 202 on the LCD 74, background data (time-invariant content data) Da 2 (for which the ID code may be ID2) is first downloaded into the data memory 62 of the receiving/reproducing terminal 20 by using the download system 100. Figure 11 illustrates an example of time invariant content data 204 of a background (outline) for a weather report. For this background, time-varying content data (denoted parts data Db2 for which the ID code may be ID2), such as weather symbols w1 through w6, barometric pressure symbols p1 and p2, and a wind-strength symbol p3 is produced. Examples of such symbols are illustrated in Figure 12. This time-varying content data is produced by the program editing terminal 26 by combining the parts in accordance with time parameters. The parts data Db2 is then transmitted from the transmitter 28 and is received and reproduced in the receiving/reproducing terminal 20.
In this case, image 204 of Figure 11, corresponding to the background data Da2 and representing a map of Japan and surrounding regions with latitude and longitude lines, is combined with the parts data Db2 representing the meteorological symbols. The resulting synthesized data is then reproduced on the LCD 74 as an image 206, as shown in Figure 13. In this case, sound information may also be transmitted and received in synchronization with the image data. In this manner, a change in the weather map can be displayed in a short period of time, and the weather forecasts can be obtained in real time.
Concerning the information-type content, such as news, weather forecasts, traffic information, meteorological information, stock broadcasting, messages, and so on, the time-invariant outline data (outline data) Da having a relatively large data capacity is first downloaded into the receiving/reproducing terminal 20 as a fixed image. Then, the time-varying parts data Db is transmitted from the transmitter 28 in real time, thereby enabling the reproduction of moving pictures in real time on the LCD 74. Note that only the time-varying data need be transmitted in real time, thus minimizing transmission system bandwidth requirements.
In the present invention, information-type content as well as entertainment-type content, which may be content data having relatively small motion requirements, such as talk shows and games, may be used. For board games (such as chess), for example, a chess board may be used as time-invariant background data Da, and the chess pieces may be time-varying parts data Db.
As discussed above, even by utilizing a small data-rate (transmission capacity) sound- or character-based communication infrastructure, such as the beeper system 14 shown in Figure 1, the data Db (Db1, Db2), which is time-varying content data having a small data capacity, can be transmitted in real time. It is thus possible to receive the data Db and to easily reproduce the resulting moving pictures and animation on the LCD 74 and from the speaker 68 of the receiving/reproducing terminal 20.
According to the broadcast system 10 implemented by utilizing the receiving/reproducing terminal 20, the convenience, entertainment characteristics, and commercial characteristics for the user are significantly enhanced. Additionally, since the data capacity handled in the program editing terminal 26 is very small, the program production cost is considerably reduced.
Although in the foregoing embodiment the beeper system 14 is used as a communication infrastructure, other systems, such as a cellular telephone system or PHS systems may be employed.
In the foregoing embodiment, the time-invariant content data Da is first downloaded into the data memory 62 of the receiving/reproducing terminal 20 by using the download system 100 including the entertainment machine 102 shown in Figure 4. Alternatively, the time-varying content data Db (or data for varying content) may be first downloaded, as illustrated in Figure 14, together with the time-invariant content data Da, from the entertainment machine 102 into the data memory 62 of the receiving/reproducing terminal 20.
In this case, as illustrated in Figure 15, command data Dc for reproducing the content data may be transmitted from the transmitter 28 at set time periods, for example, every hour, and may be received by the receiving/reproducing terminal 20.
The reproducing command data Dc contains the order of combining the outline data (background data) Da and the parts data Db, thereby allowing a moving picture similar to that shown in Figures 10 or 13 to be displayed on the LCD 74.
For this embodiment, the download system 100 is used for downloading the time-invariant content data Da and the time-varying content data Db into the data memory 62 of the receiving/reproducing terminal 20. Alternatively, a radio communication system, such as the broadcast system 10 shown in Figure 1, may be used for downloading the above described data.
According to another embodiment of the present invention, by utilizing the broadcast system 10, the time-invariant data Da having a comparatively large data capacity is first transmitted to the receiving/reproducing terminal 20. Thereafter, moving pictures are reproduced in real time on the receiving/reproducing terminal 20. Additionally, character-based images can be reproduced in real time even while the time-invariant content data Da is being transmitted.
According to this embodiment, a program schedule repeating the following broadcast cycle may be used. Figure 16 illustrates an example of a program schedule 300 using a time unit (TU) of 15 minutes. As illustrated in Figure 16, a character-based program Pc is broadcast in real time for 14 minutes and 45 seconds. A moving-picture based program Pm is then broadcast in real time for 15 seconds.
Content data, such as a character-based program Pc produced by a content provider using the terminal 22 (referred to as the "program Pc data Dp") is transmitted to the program editing terminal 26 of the transmitting apparatus 18 via the public-line network 12. Content data, such as image data, produced by another content provider using the terminal 24 (referred to as the "program Pm data Dcm1") is also transmitted to the program editing terminal 26 via the public-line network 12.
By using the program Pc data Dp and the program Pm data Dcm1 as broadcast material, the program editing terminal 26 produces, as shown in Figure 16, a program schedule 300 by using 15 minutes as a time unit (TU). The program editing terminal 26 divides the program schedule 300 into time units (TU) and continuously transmits the content data via the transmitter 28 and the transmitting antenna 16.
As shown in the enlarged diagram at the lower part of Figure 16, each time unit (TU) is formed of a comparatively long first period Tp and a relatively short second period Tf after the first period Tp. In this embodiment, the first period Tp lasts 14 minutes and 45 seconds, and the second period Tf lasts 15 seconds. The receiving/reproducing terminal 20 receives characters or very simple graphics information in real time and displays them on the LCD 74 during the first period Tp, and displays images including moving pictures in real time on the LCD 74 during the second period Tf.
The enlarged diagram in Figure 16 also illustrates a detailed configuration of the content data Dtu included in the time unit TU. In the first period Tp, program Pc data Dp, which is the first-period content data, and the program Pm data Dcm1, which is second-period first content data, are sent. In the second period Tf, program Pm command data Dcm2, which is the second-period second content data, is sent.
An ID code for identifying the program Pc data Dp is inserted at the head of the program Pc data Dp in the first period Tp. Another ID code for identifying the program Pm command data Dcm2 is inserted at the head of the program Pm command data Dcm2 in the second period Tf.
The program Pm data Dcm1, which is the second-period first content data, contains the above-described outline data Da and the parts data Db. The program Pm command data Dcm2, which is the second-period second content data, includes the above-described reproducing command data Dc. Alternatively, the second-period first content data (i.e., the program Pm data Dcm1) may be the outline data Da, while the second-period second content data (i.e., the program Pm command data Dcm2) may be the parts data Db.
In the first period Tp, the total data rate (the entire bandwidth) of 6.4 kbps, is divided. More specifically, three quarters of the total data rate, i.e., 4.8 kbps, is assigned to the program Pc data Dp to be reproduced in real time in the first period Tp. The remaining one fourth of the total data rate, i.e., 1.6 kbps, is allocated to the program Pm data Dcm1 to be reproduced in the second period Tf. In the second period Tf, the total data rate, i.e., 6.4 kbps, is assigned to the program Pm command data Dcm2 for the second period Tf.
Figure 17 is a flowchart that illustrates a receiving and reproducing process performed by the receiving/reproducing terminal 20, according to one embodiment of the present invention.
When the broadcast receiving mode is selected by the mode switching key 78M with the power on, the receiving/reproducing terminal 20 is ready to continuously receive data in step 1701. At this time, radio waves including content data sent from the transmitting apparatus 18 as broadcast waves via the transmitter 28 and the transmitting antenna 16 are received by the receiving antenna 50 for use in the receiving/reproducing terminal 20. After the RF signal is converted into an IF signal by the RF processor 52, the IF signal is demodulated and is decoded into serial data by the decoder 54. The serial data is then converted into parallel data by the SPI 56 and is output to the system bus 46.
Then, in step 1702, the ID code for identifying the program Pc data Dp and the ID code for identifying the program Pm command data Dcm2 are decoded by the decoder 54. The CPU 44 then determines, in step 1703 whether the data is the program Pc data Dp or the program Pm command data Dcm2 based on the decoded ID code. If it is determined that the data is the program Pc data Dp, the program is reproduced in step 1704, and the data is stored in step 1705. In step 1702, the ID codes may be decoded by the CPU 44.
In the program reproducing processing in step 1704, the program Pc data Dp having a data rate of 4.8 kbps is reproduced in real time. More specifically, among the program Pc data Dp, sound data is output as sound via the DAC 64, the amplifier 66, and the speaker 68, while simple image data and graphics data are displayed on the LCD 74 via the GDC/decoder 70 and the LCDC 72.
While the program Pc data Dp is being reproduced in real time in step 1704, the program Pm data Dcm1, which is the second-period first content data, having a data rate of 1.6 kbps is sequentially stored in the data memory 62 via the memory interface 60 in step 1705. The processing operation from steps 1701 to step 1705 is repeated for the first period Tp (i.e., 14 minutes and 45 seconds), during which time the program Pm command data Dcm2 is received.
After the determination is made in step 1703, that the ID code indicates program Pm command data, the process proceeds to the step 1706. In step 1706, the program Pm data Dcm1 stored in the data memory 62 is read based on the program Pm command data Dcm2 received in real time. Then, in step 1707, image processing and decoding processing (data expansion) are performed on the program Pm data Dcm1 by the GDC/decoder 70 based on the content of the program Pm command data Dcm2. As a result, a moving picture (for example, a commercial image), which reflects the graphics display and high-efficiency compression encoding technique, is displayed on the LCD 74 in real time via the LCDC 72. Simultaneously, sound is reproduced and output via the DAC 64, the amplifier 66, and the speaker 68, if necessary.
The processing of steps 1701, 1702, 1703, 1706, and 1707 is repeated for the second period Tf (i.e., 15 seconds). As a result, in the second period Tf, the reproduced moving picture 202 shown in Figure 10 or the image 206 shown in Figure 13 can be displayed on the LCD 74 in synchronization with sound.
Figure 18 is a diagram illustrating the reproduction data rate (reproducing bandwidth), which is partially overlapped with the program schedule 300 shown in Figure 4. In Figure 18, in the first period Tp (14 minutes and 45 seconds) of the time unit TU, the program Pc data Dp, which is the content data formed of character information and simple graphics and which is reproducible even at a relatively low data rate (i.e., 4.8 kbps), is reproduced in real time. In this case, three quarters of the total data rate (6.4 kbps), i.e., 4.8 kbps, is assigned to the program Pc data Dp. The remaining one fourth of the total data rate, i.e., 1.6 kbps, is allocated to the transmission of the program Pm data Dcm1, which is the second-period first content data to be reproduced in the second period Tf (15 seconds).
During the first period Tp (14 minutes and 45 seconds), the program Pm data Dcm1, which is the second-period first content data, is sequentially stored in the data memory 62 of the receiving/reproducing terminal 20. That is, at the start of the second period Tf, the amount of data expressed by the following equation (1) is stored. (1.6 kbps/8) × (14 × 60 seconds + 45 seconds) = 177 kbytes
Since all the data rate (6.4 kbps) can be used in the second period Tf, the data rate at the second period Tf results in 100.8 kbps (see Figure 18), as expressed by the following equation (2). Thus, data can be seemingly reproduced cyclically at a high bandwidth. (177 kbytes/15 seconds) + (6.4 kbps/8) = 12.6 kbytes/second = 100.8 kbps
The data rate 100.8 kbps obtained as described above is approximately twice as high as currently used highest-speed household modems, i.e., 56 kbps, about three times as high as the high data rate of PHS terminals, i.e., 32 kbps, and approximately ten times as high as the data rate of cellular telephones, i.e., 9.6 kbps. As discussed above, at this data rate, graphics display data and moving pictures reflecting the high-efficiency encoding technique can be displayed in real time.
In practice, the actual data rate should be calculated by using the effective data rate obtained by subtracting the redundancy data rate, which takes up a few percent to a few tens of percent of the data rate calculated by the equations (1) and (2). Even at this decreased data rate, moving pictures can be sufficiently reproduced.
According to the foregoing embodiment, in the first period Tp of the time unit TU, the total data rate 6.4 kbps is divided into 4.8 kbps and 1.6 kbps. By using these respective data rates, the program Pc data Dp to be reproduced in real time and the second-period program Pm data Dcm1 are transmitted from the transmitting apparatus 18. In the first period Tp, the receiving/reproducing terminal 20 reproduces the character-based program Pc data Dp in real time and displays it on the LCD 74, and also stores the second-period program Pm data Dcm1 in the data memory 62. In the second period Tf, the data stored in the data memory 62 is read, and based on this data and the program Pm command data Dcm2 transmitted in real time at the total data rate, i.e., 6.4 kbps, high data-rate moving pictures can be reproduced on the LCD 74 in real time.
With this arrangement, a transmission infrastructure having a bandwidth small enough to be received by the portable and simple receiving/reproducing terminal 20 (such as a beeper system), high-quality graphics and moving pictures, which cyclically (regularly) require a large bandwidth, can be received and reproduced for a certain period of time.
In the first period Tp having a low reproduction data rate, characters and sound, or simple graphics are received and reproduced, and then, in the second period Tf having a high reproducing rate, moving pictures are reproduced. In this manner, in the receiving/reproducing terminal 20, two types of media requiring a high data rate and a low data rate can be received and reproduced. As a consequence, the receiving/reproducing terminal 20 becomes more convenient for the user, and is also used more efficiently by the content providers whose terminals 22 and 24 are connected to the public-line network 12.
It is also possible to insert high data-rate data, such as moving pictures, between programs, which are character-based content data, thereby enabling the construction of a media system which is commercially most effective.
In the embodiment shown in Figures 16, 17, and 18, the time-invariant content data Da and the time-varying content data Db are transmitted together in the first period Tp, and the reproducing command data Dc is transmitted in the second period Tf. Based on the reproducing command data Dc, a moving picture is reproduced. However, the present invention is not restricted to the above configuration. As stated above, only the time-invariant content data Da may be transmitted in the first period Tp, and the time-varying content data Db may be transmitted in the second period Tf in a desired order. With this modification, a moving picture can be reproduced on the LCD 74 according to the receiving order of the time-varying data Db, in which case, the reproducing command data Dc is made unnecessary.
It should be noted that the present invention is not limited to the disclosed embodiment. Instead, embodiments of the present invention are intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. For example, a download source of the download system 100 is not restricted to the optical disc 156, and may be tape, a ROM cassette, a modem, or the like.
According to the present invention, even by utilizing an infrastructure having a comparatively low data rate, images including moving pictures can be cyclically or non-cyclically reproduced in real time for a certain period of time on a receiving/reproducing terminal. Thus, it is expected that novel broadcast media can be constructed by the application of the broadcast system or the receiving/reproducing terminal of the present invention.
In the foregoing, a broadcast system and a receiving/reproducing terminal for reproducing broadcast content in real time has been described. Although the present invention has been described with reference to specific exemplary embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the invention as set forth in the claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.

Claims

A broadcast system transmitting and receiving content as data in real time, comprising:

a download unit transmitting time-invariant content data;

a transmitting apparatus transmitting time-varying content data as radio waves; and

a receiving/reproducing terminal including a storage device, the time-invariant content data transmitted from the download unit being stored in the storage device, and the receiving/reproducing terminal reproducing the content in real time from the time-invariant content data and the time-varying content data upon receiving the time-varying content data from the transmitting apparatus.
A broadcast system according to claim 1, wherein the time-invariant content data comprises one of background image data and outline image data, and the time-varying content data comprises image data of an image to be superimposed on one of a background image corresponding to the background image data and an outline image corresponding to the outline image data.
A broadcast system according to claim 1 wherein the time invariant content data is transmitted from the download unit prior to the time-varying content data being transmitted by the transmitting apparatus.
A broadcast system according to claim 3 wherein the time invariant content data is coded with a first identification code, and the time-varying content data is coded with a second identification code.
A broadcast system transmitting and receiving content as data in real time, comprising:

a download unit transmitting content data;

a transmitting apparatus transmitting reproducing command data as radio waves; and

a receiving/reproducing terminal including a storage device, the content data transmitted from the download unit being stored in the storage device in advance, and the receiving/reproducing terminal reproducing the content in real time from the downloaded content data based on the reproducing command data upon receiving the reproducing command data from the transmitting apparatus.
A broadcast system according to claim 5, wherein the content data transmitted from the download unit in advance comprises time-varying content data and time-invariant content data.
A broadcast system according to claim 6, wherein the time-invariant content data comprises one of background image data and outline image data, and the time-varying content data comprises image data of an image to be superimposed on one of a background image corresponding to the background image data and an outline image corresponding to the outline image data.
A broadcast system according to claim 6 wherein the time invariant content data is transmitted from the download unit prior to the time-varying content data being transmitted by the transmitting apparatus.
A broadcast system according to claim 8 wherein the time invariant content data is coded with a first identification code, and the time-varying content data is coded with a second identification code.
A broadcast system transmitting and receiving content as data in real time, comprising:

a transmitting apparatus transmitting time-invariant content data and time-varying content data as radio waves; and

a receiving/reproducing terminal including a storage device, the time-invariant content data transmitted from the transmitting apparatus being stored in the storage device in advance, and the receiving/reproducing terminal reproducing the content in real time from the time-invariant content data and the time-varying content data upon receiving the time-varying content data as the radio waves from the transmitting apparatus.
A broadcast system according to claim 10, wherein the time-invariant content data comprises one of background image data and outline image data, and the time-varying content data comprises image data of an image to be superimposed on one of a background image corresponding to the background image data and an outline image corresponding to the outline image data.
A broadcast system according to claim 11 wherein the time invariant content data is transmitted by the transmitting apparatus prior to the time-varying content data being transmitted by the transmitting apparatus.
A broadcast system according to claim 12 wherein the time invariant content data is coded with a first identification code, and the time-varying content data is coded with a second identification code.
A broadcast system according to claim 13 wherein the time invariant content data and time-varying content data are transmitted over a cyclical program, the cyclical program being divided into a sequence of time units, each time unit divided into a first time period and a second time period.
A broadcast system according to claim 14 wherein the time invariant content data is transmitted during the first time period, and the time-varying content data is transmitted during the second time period.
A broadcast system according to claim 15 wherein the first time period is longer than the second time period.
A broadcast system transmitting and receiving content as data in real time, comprising:

a transmitting apparatus transmitting time-invariant content data and time-varying content data as radio waves, and also transmitting reproducing command data; and

a receiving/reproducing terminal including a storage device, the time-invariant content data and the time-varying content data transmitted from the transmitting apparatus being stored in the storage device in advance, and the receiving/reproducing terminal reproducing the content in real time from the time-invariant content data and the time-varying content data based on the reproducing command data upon receiving the reproducing command data from the transmitting apparatus.
A broadcast system according to claim 17, wherein the time-invariant content data comprises one of background image data and outline image data, and the time-varying content data comprises image data of an image to be superimposed on one of a background image corresponding to the background image data and an outline image corresponding to the outline image data.
A broadcast system according to claim 17 wherein the time invariant content data is transmitted by the transmitting apparatus prior to the time-varying content data being transmitted by the transmitting apparatus.
A broadcast system according to claim 19 wherein the time invariant content data is coded with a first identification code, and the time-varying content data is coded with a second identification code.
A broadcast system according to claim 20 wherein the time invariant content data, time-varying content data, and reproducing command data are transmitted over a cyclical program, the cyclical program being divided into a sequence of time units, each time unit divided into a first time period and a second time period.
A broadcast system according to claim 21 wherein the time invariant content data and time-varying content data are transmitted during the first time period, and the reproducing command data is transmitted during the second time period.
A broadcast system according to claim 22 wherein the first time period is longer than the second time period.
A receiving/reproducing terminal comprising:

a data input unit inputting content data;

a data storage unit storing the content data;

a data reproduction unit reproducing the content data; and

a control unit controlling the data input unit, the data storage unit, and the data reproduction unit,
wherein the control unit stores time-invariant content data supplied from an external source via the data input unit in the data storage unit, and the control unit reproduces, upon receiving time-varying content data from the external source via the data input unit, the content from the time-varying content data and the time-invariant content data in real time by using the data reproduction unit.
A receiving/reproducing terminal according to claim 24, wherein the time-invariant content data comprises one of background image data and outline image data, and the time-varying content data comprises image data of an image to be superimposed on one of a background image corresponding to the background image data and an outline image corresponding to the outline image data.
A receiving/reproducing terminal comprising:

a data input unit inputting content data;

a data storage unit storing the content data;

a data reproduction unit reproducing the content data; and

a control unit controlling the data input unit, the data storage unit, and the data reproduction unit,
wherein the control unit stores time-invariant content data and time-varying content data supplied from an external source via the data input unit in the data storage unit in advance, and the control unit reproduces, upon receiving reproducing command data from the external source via the data input unit, the content from the time-varying content data and the time-invariant content data in real time based on the reproducing command data by using the data reproduction unit.
A receiving/reproducing terminal according claim 28, wherein the time-invariant content data comprises one of background image data and outline image data, and the time-varying content data comprises image data of an image to be superimposed on one of a background image corresponding to the background image data and an outline image corresponding to the outline image data.
A method of transmitting and receiving content as data in real time, comprising the steps of:

transmitting time-invariant content data from a download unit;

transmitting time-varying content data as radio waves from a transmitting apparatus;

storing the time-invariant content data transmitted from the download unit in a storage device of a receiving/reproducing terminal;

receiving the time-varying content data from the transmitting apparatus in the receiving/reproducing terminal; and

reproducing the content in real time in the receiving/reproducing terminal from the time-invariant content data and the time-varying content data upon receiving the time-varying content.
A method according to claim 28, wherein the time-invariant content data comprises one of background image data and outline image data, and the time-varying content data comprises image data of an image to be superimposed on one of a background image corresponding to the background image data and an outline image corresponding to the outline image data.
A method according to claim 28 wherein the step of transmitting the time invariant content data is performed prior to the step of transmitting the time-varying content data.
A method according to claim 30 further comprising the steps of:

coding the time invariant content data with a first identification code; and

coding the time-varying content data with a second identification code.
A method according to claim 28 further comprising the steps of:

transmitting reproducing command data as radio waves from the transmitting apparatus; and

reproducing the time invariant content data and time-varying content data in real time in the receiving/reproducing terminal based on the reproducing command data.
A method of transmitting and receiving content as data in real time, comprising the steps of:

transmitting time invariant content data as radio waves from a transmitting apparatus;

transmitting time-varying content data as radio waves from the transmitting apparatus;

receiving the time invariant content data and time-varying content data in a receiving/reproducing terminal;

storing the time-invariant content data transmitted from the transmitting apparatus in a storage device of the receiving/reproducing terminal; and

reproducing the content in real time from the time-invariant content data and the time-varying content data in the receiving/reproducing terminal upon receiving the time-varying content data from the transmitting apparatus.
A method according to claim 33, wherein the time-invariant content data comprises one of background image data and outline image data, and the time-varying content data comprises image data of an image to be superimposed on one of a background image corresponding to the background image data and an outline image corresponding to the outline image data.
A method according to claim 34 wherein the step of transmitting the time invariant content data is performed prior to the step of transmitting the time-varying content data.
A method according to claim 35 further comprising the steps of:

coding the time invariant content data with a first identification code; and

coding the time-varying content data with a second identification code.
A method according to claim 33 further comprising the steps of:

transmitting reproducing command data as radio waves from the transmitting apparatus; and

reproducing the time invariant content data and time-varying content data in real time in the receiving/reproducing terminal based on the reproducing command data.
A method according to claim 33 further comprising the steps of

transmitting the time invariant content data and time-varying content data over a cyclical program;

dividing the cyclical program into a sequence of time units; and

dividing each time unit into a first time period and a second time period.
A method according to claim 38 further comprising the steps of:

transmitting the time invariant content data during the first time period; and

transmitting the time-varying content data during the second time period.
A method according to claim 39 wherein the first time period is longer than the second time period.