Abstract:
An approach to recording of television programming for later viewing makes use of a small and relatively inexpensive handheld portable viewer. One or more television programs are loaded into the viewer from a receiver, such as a cable television set-top box. Later, the user selects a loaded program for viewing on the handheld viewer

Description:
BACKGROUND 
     This invention relates to viewing recorded television programming in a portable device. 
     Today, television programming is typically viewed on a television set that receives programming that is broadcast over the air from local television stations, or distributed over a cable or satellite-based television network to an in-home terminal such as a “cable box” (also known as a set-top box or a home communication terminal, HCT) that is connected to the viewer&#39;s television set. Portable television sets are available for receiving and viewing programming as it is broadcast from local television stations. 
     Television programming can be recorded on a video tape recorder for later viewing. The most common type of recorder uses VHS tape cartridges. Portable players for recorded VHS tapes are available, for example, integrated with television sets. However, such integrated units are typically large, heavy and not portable, although some players are available for use in cars. In addition to recording television programming on VHS tapes, users can buy or rent prerecorded VHS tapes, for example, with movies recorded on them. DVDs (Digital Video Disks, Digital Versatile Disks) are becoming more popular than VHS for prerecorded movies and programming, and relatively small but expensive portable DVD players are available. As in-home recorders for DVDs become available it is expected that recordable DVDs will begin to replace VHS tapes as a common type of recordable medium. Television programming can also be recorded on an internal storage device in a digital recorder (also known as a Personal Video Recorder, PVR) in the home for later viewing. 
     Recording and viewing of television programming using the approaches and devices described above either makes use of relatively large and heavy equipment, such as a VHS tape player and a portable television set, or uses expensive equipment such as an in-home DVD recorder and a portable DVD player. 
     SUMMARY 
     In a general aspect, the invention features an approach to the recording of television programming for later viewing on a small and relatively inexpensive hand-held viewer. One or more television programs are loaded into the viewer from a receiver, such as a cable television set-top box. Later, the user selects a loaded program for viewing on the handheld viewer. 
     In one aspect, in general, the invention features a method for portable viewing of television programs. One or more television programs are received at a terminal coupled to a television system. A first of the television programs is encoded at the terminal. This encoding includes digitally compressing the first of the television program. Communication is established between a portable device and the terminal. This includes downloading the encoded first of the television programs from the terminal to the portable device. At the portable device when it is not in communication with the terminal, a command is accepted from a user to play the downloaded first of the television programs. In response the play command from the use-, the portable device presents the downloaded program to the user using a screen on the portable device. 
     In another aspect, in general, the invention features a portable device for viewing of audio-video programs. The portable device has a communication port for communicating with a terminal coupled to a television system. A memory in the device is used for storing digitally compressed audio-video programs received through the communication port from the terminal, and a screen on the device is used for displaying video of the stored programming. The device includes a processor coupled to the communication port, the memory, and the screen. The processor is programmed to control operation of the device by downloading digitally compressed audio-video programming from the communication port, storing the programming in the memory, accepting commands from a user, and playing the stored programming to the user according to the accepted commands. 
     In yet another aspect, in general, the invention features a system for viewing television programs. The system includes a terminal coupled to a television system, such as a set-top box connected to a cable television system. The terminal includes a receiver for accepting television programs from the television system, a decoder for transmitting the programs to a television set, and an encoder for processing accepted television programs by digitally compressing the programs. The system also includes a portable device for viewing television programs. The portable device includes a communication port for communicating with the terminal, a memory for storing digitally compressed television programs received through the communication port from the terminal, a screen coupled for displaying video of the stored programming, and a processor. The processor is programmed to control operation of the device by downloading digitally compressed television programs through the communication port, storing the programs in the memory, accepting commands from a user, and playing the stored programs to the user according to the accepted commands. 
     Aspects of the invention can include one or more of the following advantages. 
     The device can be small and light, which increases its portability. For example, the device can be significantly smaller and lighter than a VHS tape player. 
     The device does not have to provide the full resolution of a television set. This can make the device less expensive, for example, as compared to a portable DVD player. 
     The functionality of the portable device can be provided, at least in part, by a commercially available programmable game console that accepts cartridges, which may make the device less expensive. 
     Other features and advantages of the invention are apparent from the following description, and from the claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a front view of a portable viewer; 
         FIG. 2  is a block diagram that illustrates use of a portable viewer in conjunction with a cable television system; 
         FIGS. 3A-3C  are diagrams that illustrate alternative program downloading approaches; 
         FIG. 3A  is a diagram that illustrates a cradle into which a portable cradle is inserted; 
         FIG. 3B  is a diagram that illustrates wireless downloading; 
         FIG. 3C  is a diagram that illustrates a recordable cartridge that is used to download programming; 
         FIG. 4  is a flowchart of operation of the system; and 
         FIG. 5  is a block diagram that illustrates components of a portable viewer and a cable box. 
     
    
    
     DESCRIPTION 
     1 Overview ( FIGS. 1 and 2 ) 
     Referring to  FIG. 1 , a portable viewer  140  is used to play a television program that a user previously downloaded to the viewer. The portable viewer  140  is battery operated and includes a built-in screen  150  for displaying the video for the program and a built-in speaker  148  for playing the audio for the program.  FIG. 1  shows one version of the viewer, illustrated approximately to scale and at actual size. Overall, this version of the viewer is approximately six inches high and four inches wide, thereby making it suitable for hand-held use. Optional or removable handles  144  protrude from the sides of the viewer to make it easier for a user to hold. The user controls the portable viewer  140  using an on-off switch  146 , which optionally also controls the volume of the audio played on the speaker  148 , and a brightness control  142 , that controls the brightness of the video displayed on the screen  150 . The portable viewer  160  also includes a keyboard  160 , which includes both alphabetic and numeric keys, through which the user enters commands or other information. As is discussed further below with reference to operation of the device, these commands include requests to display particular downloaded programs if multiple programs have been downloaded to the player. 
     Referring to  FIG. 2 , the user  100  downloads television programs from a cable television system  110  to the portable viewer  140 . In normal viewing of television programs, the user  100  uses a standard remote control  125  which controls a cable box  120  and a television set  130  to present television programs to the user  100 . For example, the user  100  uses the remote control to select a desired station on the cable box  120  and uses the remote control to adjust the audio volume on the television set  130 . 
     In addition to standard features, cable box  120  communicates with the portable viewer  140  to download data that encodes a television program to the portable viewer. Furthermore, the cable box  120  receives commands sent by the user  100  using the remote control  125  that cause the cable box  120  to download particular programs to the portable viewer. For example, one such command causes the cable box  120  to download the television program that is currently being presented on the television set  130  to the portable viewer  140 . This can be useful if the user  100  cannot watch the end of a program because the user can then command the cable box to download the remainder of the program so that he or she can later view it on the portable viewer  140 . 
     After the program is downloaded to the portable viewer  140 , the user  100  takes the viewer with him or her away from the cable box  120 , for example, to another room in the house or a trip in a car. While away, the user  100  uses the portable viewer  140  to watch the downloaded program. 
     2 Downloading Programs to the Portable Viewer  140  ( FIGS. 3A through 3C ) 
     Referring to  FIG. 3A , the first version of the portable viewer  140  uses a cradle  122  for communicating with the cable box  120 . The cradle  122  has a slot  124  into which the portable viewer  140  is inserted so that the cable box can download programs to the viewer. The slot includes the ends of wires leading to the cable box over which the downloaded television program is sent to the viewer, and the viewer includes wires that touch the wires in the cradle when it is inserted so that it can receive the downloaded television program. 
     In  FIG. 3A , the cradle  122  is shown as a being separate from the cable box  120 . In another version of the system the slot  124  can be built into the cable box so that the portable viewer  140  can be inserted directly into the cable box. 
     There are other ways in which the downloaded television program can be sent to other versions of the portable viewer  140 . Referring to  FIG. 3B , the portable viewer  140  can be placed close to the cable box  120  without actually plugging it in or inserting it into a slot or cradle. The downloaded television program is then sent through the air from a transmitter  128  on the cable box to a receiver  148  on the portable viewer  148 . For example, such wireless communication can work like a remote control so that the cable box shines a light that carries the television program to the portable viewer. This could also work like a radio so that the receiver  148  has a small radio receiver for receiving the television program transmitted from the cable box. 
     Referring to  FIG. 3C , another version of the portable viewer  140  uses a small cartridge  190 , which is similar to a Gameboy® cartridge. In this version of the system, there is again a cradle  122  as was shown in  FIG. 3A , but rather than inserting the entire portable viewer  140  into a slot, the cartridge  190  is inserted into another kind of slot  126 . The television program is sent from the cable box  120  to the cartridge  190 . The user then takes the cartridge out of the cradle  126  and inserts it into the portable viewer  140 . 
     3 Using the Portable Viewer  140  ( FIG. 4 ) 
     Referring to  FIG. 4 , operation of the system generally follows a sequence of steps shown in the figure. First, the user sends a command to the step-top box to select the program to download (step  210 ). This command can take a number of forms, including a command to download the current television program being viewed by the user, or a command to download a particular program at a later time. Choosing such a later program can involve browsing through a program guide that is displayed on the television set and selecting the program on the display. The user leaves the portable viewer  140  connected to the cable box  120 . 
     When the television program is available, the cable box  120  converts the television program so that it can be downloaded into the portable viewer  140  (step  220 ). In general, the screen  150  of the portable viewer has less resolution (for example, a fewer number of dots on the screen, fewer different colors that can be concurrently displayed, or fewer images per second) than a television set, so the video of the television program is converted so that it can be displayed at that lower resolution. Also, the portable viewer may have a limited amount of space to store the television program, so the cable box may have to convert the program so that it does not take up as much space using a digital compression approach, for example, also reducing the resolution. The audio part of the television program may also be converted so that it has an appropriate format and size for downloading to the portable viewer  140 . The cable box then downloads the converted television program to the portable viewer  140  using one of the types of mechanisms that are shown in  FIGS. 3A-3C . 
     The user then takes the portable viewer  140  with him or her, for example on a trip (step  230 ). The portable viewer  140  does not need to be turned on to keep the program stored in it. 
     Later, when the user wants to watch a downloaded television program, he or she turns on the portable viewer  140  using the on-off switch  146  and selects which program he or she wants to watch, for example, by typing the name of the television program on the keyboard  160  of the portable viewer  140  (step  240 ). 
     In response to the user&#39;s input that selects the program, the portable viewer  140  plays the downloaded television program using the screen  150  and the speaker  148  in the portable viewer (step  250 ). The user can also input commands to pause or rewind the program, and can adjust the brightness of the screen using the brightness knob  142 . 
     4 Internal Components ( FIG. 5 ) 
     Referring to  FIG. 5 , portable viewer  140  includes a number of internal components. The viewer includes a communication port  330  through which downloaded television programs pass from the cable box  120  to other components inside the portable viewer  140 . In the version of the portable viewer that plugs into a slot  124  in a cradle  122  (see  FIG. 3A ), the communication port  330  includes the wires and circuits that connect to the wires in the cradle. 
     The portable viewer  140  includes a computer processor (also referred to as a central processing unit, or CPU)  370  that runs a program that controls operation of the portable viewer. It uses a program that is stored in a memory  340 . One program that the CPU  370  runs is used to receive the downloaded television program from the communication port  330  and to store it in the memory  340 . 
     Another program that the CPU  370  runs lets the user choose the downloaded program to play. The CPU  370  can tell what the user is typing on the keyboard  160  using a keyboard interface  360  that includes electronic circuits that are connected to the keys of the keyboard. Based on the commands that the user types, the program gets the stored television program from the memory  340 . The stored television program needs to be converted so that it can be played on the screen  150  and speaker  148 . The portable viewer includes an audio/video decoder  350 , which includes specialized electronics for converting the stored television program into the appropriate form for playing. 
     In the versions of the portable viewer  140  that use a removable cartridge  190  (see  FIG. 3C ), the cartridge becomes part of the memory  340  when it is inserted in the portable viewer  340  so that the CPU  370  can get the stored television program to pass through the audio/video decoder  350 . 
     The cable box  120  includes a transceiver/tuner  310  that is used to communicate with the rest of the cable television system. For example, the transceiver/tuner includes the electronic circuits that tune the box to a chosen television station. The television programs come from the cable television system and are received by the transceiver/tuner before being passed to other components in the cable box  120 . For playing television programs on the television set, the cable box includes a decoder  315  that converts the television program into the appropriate format so that it can be played on an attached television set. For example, the decoder makes it look like the television program is coming in on channel  3  even through the cable box  120  is tuned to channel  25 . 
     In addition to these standard components, the cable box  120  includes an encoder  320 . Recall that the cable box  120  generally needs to convert the format of the television program so that it can be downloaded to the portable device. The encoder  320  is that part of the cable box that does this conversion. 
     The components of the cable box  120  are illustrated without showing whether they are implemented using electronic circuits, computer programs, or both. In general, they are implemented using a combination of specialized circuits and a computer processor that runs a program inside the cable box. 
     5 Other Versions 
     The versions of the portable viewer  140  described above can be specially built for playing television programs. Another version of the system uses portable devices that were designed for another purpose. One such version uses a portable game player, such as a Nintendo Gameboy Color® or a Gameboy Advance®. This version of the system is like the version shown in  FIG. 3C  with the cartridge being compatible for insertion into a Gameboy. Because the Gameboy was not designed to play television programs, part of the program that controls how the television programs are played is also stored on the Gameboy cartridge. 
     Another version of the system uses a portable viewer  140  that is built to play television programs. In addition, it has a slot so that a game cartridge, such as a Gameboy cartridge, can be plugged in and the portable viewer can be used to play a game. With this version, the user does not need two separate devices if he or she wants to both play games and view television programs on a trip. 
     If a cartridge version of the portable viewer becomes popular, stores could sell or rent cartridges to users so that they can view the programs that have already been downloaded to the cartridges. 
     Another version of the portable viewer  140  has a built-in television tuner so that the user can watch locally broadcast television programs that he or she did not download. 
     Another version of the viewer is meant for use in a car, and plugs into a cigarette lighter to get its power without running down its batteries. Another version for a car is built in and uses cartridges that are plugged into it. 
     Other versions of the viewer can be larger or smaller than the one shown in  FIG. 1 . The screen can be about two inches by two inches in size, or larger or smaller, and can be the same type that is used on laptop computers (for example, a liquid crystal display, LCD). Also, the arrangement of controls can be different than shown in  FIG. 1 . For example, the brightness knob  142  can be hidden behind a door so that it is not accidentally adjusted. Also, instead of a keyboard, other kinds of buttons with arrows or markings. 
     Another version of the system uses television programs that have already been recorded in a recorder in the user&#39;s house. For example, if the user has already recorded a program in a personal video recorder (PVR), such as a TiVo® record, the PVR rather than the cable box communicates with the personal viewer and downloads an appropriately formatted program into the portable viewer. 
     The approach described above can work equally well with a satellite television system as with a cable television system. The function of the cable box could also be performed by a personal computer that receives television programs and movies over a network such as the Internet. 
     The approach described above is equally applicable to television programs, including cartoons, as well as live people, as well as movies.