A system and a method for minimizing and maximizing the displays in a Television Field of the invention:
The present invention relates to a system and a method for switching between displays and more particularly to a system and a method for minimizing and maximizing the displays in a display device according to the user preference.
Background of the Invention:
At present, there are a large number of television channels, which users may select for viewing. During commercial interruptions, the users may opt for other channels to determine if there is something more interesting to watch than what is on the presently selected channel.
Channel selection systems with apparatus for swapping or exchanging two channels are known. A receiver with such swapping apparatus is disclosed in an article entitled "Farbfernsehgerat mit Mikroprozessor-Steuerung" by Wolfgang Baum appearing in German language magazine "Funkschau,"1977, Heft 17. This limits the usefulness of this type of channel swapping apparatus. While such channel swapping apparatus is acceptable for switching between two channels, e.g., to follow the progress of two sporting events, it is not well suited for switching between large number of channels and then returning to an originally selected channel. In addition, such channel swapping apparatus is not well suited for use with channel selection systems of the indirect type by which channels can only be selected by the use of "up" and "down" scanning buttons which cause the channel number to be sequentially increased or decreased since it does not permit the exchange or swapping of non-consecutive channels.
US Patent No. 4,271,532 overcomes the above-mentioned demerit. This patent discloses a television tuning system for swapping or exchanging a currently selected channel for a previously saved channel when a user operates a switch provided for that purpose. As depicted by Figure 1, the system is arranged so that the saved channel is unaffected by channel selections such that it may be used by a user to quickly return to an originally selected channel after scanning other channels, e.g., during commercial interruptions, as well as to follow the progress of two or more programs.

During commercial interruptions, the user may wish to examine other channels and sometimes may forget to switch back to the channel, which he/she was previously viewing. This patent does not have any provision for either recalling the channel number of saved program. If user forgets the channel he had stored, he has no option but to swap it back to the screen to check it. Further, since the starting point of such an operation in the disclosed apparatus is storing the originally selected channel, it is not particularly well suited to immediately select a certain favorite channel without having regard to the originally selected channel before a search. In other words, this arrangement only permits the channel originally selected before a search, to be immediately recalled.
An apparatus, which enables a user to store and then unconditionally recall a favorite channel, which is frequently watched, is disclosed in the US Patent No. 4,367,559. In addition, since channel swapping and favorite channel features are different, the apparatus according to this patent provides both features. This patent however, dos not provide any facility for selecting channels desired by a user or for minimizing and maximizing channels according to the user preference.
US6,865,746 provides an improved Electronic program guide with related-program search feature to view a large number of channels provided by the cable operator.
US 5,673,089 disclose an apparatus and method for selecting channels on a television system by theme. A remote controller for the television system includes a plurality of theme keys, each theme key corresponds to one theme of the plurality of themes, apparatus for entering channel indicators corresponding to each theme, apparatus for storing the entered channel indicators corresponding to each theme, apparatus for accessing and transmitting to the television system, each channel indicator corresponding to a first theme of the plurality of themes in sequence to control channel selection for the television system, if a first theme key corresponds to the first theme is pressed, apparatus for pausing a set period of time after accessing and transmitting a channel indicator before continuing to access and transmit channel indicators corresponding to the first theme in sequence, and apparatus for stopping the apparatus for accessing and transmitting from accessing

and transmitting each channel indicator corresponding to a first theme of the plurality of themes in sequence, if the first theme key is pressed again.
US 6,212,541 provide a system and method for switching between software applications in multi-window operating system. This is a computer implemented method and system for switching from one application to a second application.
US 6,963,611 provide a process and device for switching digital television programs. This is a process for coding compressed video data streams relating to television programs to provide adapted video data streams. This patent discloses a process of encoding unviewed incoming channels.
None of the above-mentioned patents disclose a system or method to recall a previously visited channels upon user request and display the program as a minimized channel at the bottom of the display screen or maximize the minimized channel when desired by the user,
It is therefore an object of the present invention to provide a user-friendly system and method to select channel according to the user's preference.
The features of the present invention is totally user independent and is based on the concept that it's the user who is the master and his preferences are not fixed but vary depending on his mood as well as content of channels. Generally, TV remote control provides "swap" functionality. Using this functionality, one can go to last visited channel but cannot switch between the channels of his/ her choice (which is dynamically decided). With the feature of the present invention, user can select and switch between n watched channels (visited channels are different from watched channels), which he wants to revisit after some gap. In most of the cases to differentiate between visited & watched channels a threshold time is set and if the user wants to make that particular channel as a watched channel, the user has to wait for a predetermined time interval which should be greater than threshold time.
However, in the present invention, the user has the complete control and just a key press will ensure that the particular channel is added to the minimized channel list.

Object and Summary of the Invention:
It is an object of the invention to provide a system and a method for switching between displays or channels.
It is another object of the invention to provide a system and method to recall previously visited channels upon user's request and display the program as a minimized channel on the screen display.
It is yet another object of the invention to maximize the minimized channel.
It is still another object of the invention to maintain a time frame of a display bar containing the minimized channels at the bottom of the screen.
To meet the above-mentioned objectives, the present invention provides a system for switching between displays comprising:
a display device having an on screen display;
an external device for generating at least one input signal corresponding to a key activated by a user, said external device having: an infrared transmitter; a first enabling key; a second enabling key, and an output key;
an infrared receiver for receiving said input signal; and
a controller coupled to said receiver for receiving the input signal, verifying the authenticity and processing said input signal for the particular key activated by the user by invoking the appropriate routine, said controller comprising
a storage means for storing the data generated responsive to the input signal
corresponding to the first enabling key;
a control module for retrieving the data from the storage means and displaying
said data on the on screen display of the display device and
a timer for setting time frame of a display bar.

In another embodiment, the present invention, provides a method for switching between displays comprising the steps of:
generating at least one input signal corresponding to a key activated by a user by
an external device;
receiving said input signal by an infrared receiver;
verifying the authenticity of the input signal and processing said input signal for a
particular key by a controller;
storing the data generated by the controller responsive to the input signal
corresponding to the first enabling key in a storage means;
retrieving the data from the storage means by a control module;
displaying said data on an on screen display; and
setting a time frame of a display bar by a timer.
Brief description of the accompanying drawings:
These and other aspects of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings in which like designations are used to designate substantially identical elements.
Figure 1 represent a system for switching between displays or channels according to the present invention. -
Figure 2 illustrates a flow chart for operating the system of the present invention. Detailed description of the invention
Although various embodiments of the present invention are possible but for the purpose of illustration and without any limitation the present invention is described with specific reference to a television set.
The term display wherever used in the description is interchangeable with channel.

Figure 1 is a system (200) according to the present invention for switching between displays or channels. The said system comprises an external device (201), an infrared receiver (202), a controller (203) and a display device (204). The external device may preferably include a remote control or a keyboard, The external device comprises a minimize key or a first enabling key (201.2), a left/right key or a second enabling key (201.3) and an enter key or an output key (201.4). The external device has an infrared transmitter (201.1), which generates an input signal corresponding to a key press by the user. The infrared receiver receives said input signal and generates an enabling signal or an activated signal to activate the controller (203) coupled to the infrared receiver. The controller receives said input signal sent by the infrared receiver and verifies the authenticity of the said input signal for the particular key activated by the user by invoking the appropriate routine and processes the said signal. The storage means (203.1) stores the data generated by the controller responsive to the input signal. In other words, when the user presses the minimize key/ first enabling key, the external device sends an input signal to the infrared transmitter, which is transferred to the controller. The controller then processes this signal by invoking the appropriate routine and stores the output generated by the controller in a memory. For example, if the user first select the HBO channel and wants to minimize it, then as soon as he/she presses the minimize key, the information in the HBO channel is stored in the memory. Similarly, the user can store more than one channel in the memory. The controller comprises a control module (203.3) for retrieving the data from the storage device and displays it on the on screen display (204.2) of the display device (204). The minimized channels are displayed in a display bar (204.2) preferably at the bottom of the screen of the display device so that user can easily select his/her desirable channel whenever required. The controller comprises a timer (203.2) for controlling the time for which minimized channels list bar or display bar is to be shown at the bottom. To maximize the minimized channel from the display bar, the user can use the output key or enter key. To switch back and forth between the two channels, user has to press left/right keys provided in the remote control or select the switching option provided in the on screen display.
In overall the controller performs the following functions: Track the user key responses, Initiate the appropriate function call routine, Display appropriate on screen display,

Maintain the timers,
Maintain the stack to perform the store/fetch/delete operations for individual
channels and
Memory store and fetch operation.
The present invention also provides a system and a method to recall and store previously visited channels upon user request and display the program as a minimized channel at the bottom of the screen. For example, if the user is watching a movie on HBO and during the commercial starts to surf other channels and finds a good match coming on ESPN. There's a good chance that he will forget the channel he was watching earlier. Now in the current scenario he can just minimize the current channel (HBO) before moving on to surf other channels.
The bar containing the minimized channel(s) is timed so as to suit user preference, with an additional option for permanent display of minimized programs.
Figure 2 illustrates a flow chart for operating the system of the present invention. The external device or remote control (201) generates an input signal corresponding to the key pressed by the user by an Infrared transmitter (201.1) in step 301. Then said input signal is received by an infrared receiver (202) in step 302. In step 303, the controller (202) verifies the authenticity of said input signal. If the input signal is proper and valid, the controller then selects the appropriate routine for encoding depending upon key pressed in step 305, else the user presses another key on the remote control as per his/her requirement in step 304. The controller checks whether the key pressed by the user is the left/right key or second enabling key of the remote control in step 306. If the key pressed is not the left/right key, the controller again checks whether the key pressed is the minimized key or the first enabling key in step 307. If the key pressed is the minimized key, then the current channel is added to the minimized channel list or to the display bar at the bottom of the screen of the display device in step 308. Then in step 309, the user switches to the next channel. If the key pressed by the user is other than the left/right key or minimized key, then the controller executes the desired key routine corresponding to the key selected by the user in step 310. On the other hand if the key pressed by the user is the left/right key, then the controller again verifies whether there is any minimized channel already existing in the minimized channel list or display bar

in step 311. If a minimized channel already exists in the display bar, then the controller moves the cursor one position left or right depending upon the key pressed in step 312. The controller again verifies whether the key pressed is left/right key in step 313. If the key pressed is left/right key, then steps 311 to 313 are repeated, else, the controller verifies whether the key selected by the user is the enter key or the output key in step 315. If the key pressed is the enter key then the controller verifies whether the current channel is the selected channel by the user in step 316. If the current channel is the selected channel by the user, then said channel is displayed on the on screen display in step 318, else the controller switches to new selected channel in step 317. On the other hand if the key pressed by the user is not the enter key the controller does the appropriate operation depending upon the key selected by the user in step 319.
In an overall the flow chart of Figure 2 shows the flow of routine in case the user presses a minimize key or any other related key. In this case:
- Controller will check whether the key pressed is the left/right key, in which case it will transfer the
control to the corresponding module which will move the cursor among the previously minimized
channels( if any).
- If the key pressed is the minimized key, the channel will be minimized and added to the
previously minimized channels list and the background will display the next channel.
- If Enter Key is pressed then the channel selected by cursor will be maximized.
User can minimize a channel he/she is viewing by either by:

a) Pressing a direct key (minimize key) on the remote control or
b) Selecting an option provided for the same in the OSD.
The channel minimized is shown as an icon on a display bar placed at the bottom of the screen and next channel is displayed as new channel. User can now change the channel on the screen to any other of his choice as normally done. The name of the minimized channel is fetched from stored memory and displayed on the icon for easy identification of the minimized channel.

To switch back and forth between two channels user has to:
a) Press left/right keys provided on the remote control or
b) Select the switching option provided in the OSD.
To minimize another channel same procedure needs to be followed. Now the icons in the bottom bar will increase to two.
The user can switch between the 3 channels in either cyclic manner by pressing left/right keys or switch directly to a channel by selecting option on the OSD wherein a menu will pop up showing currently minimized channels.
The display bar comprises minimized channels displays time will vary depending on user preference. OSD will have an option to set the time by the user for which bar is to be shown on screen along with an option for permanent display.
To close a minimized channel the user can either
a) Press the minimize key continuously for a predetermined time period or
b) Select Corresponding option from OSD menu.
All documents cited in the description are incorporated herein by reference. The present invention is not to be limited in scope by the specific embodiments and examples, which are intended as illustrations of a number of aspects of the invention and any embodiments which are functionally equivalent are within the scope of this invention. Those skilled in the art will know, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. These and all other equivalents are intended to be encompassed by the following claims.

We claim:
1. A system for switching between displays comprising: a display device having a on screen display;
an external device for generating at least one input signal corresponding to a key activated by a user, said external device having:
an infrared transmitter;
a first enabling key;
a second enabling key, and
an output key;
an infrared receiver for receiving said input signal; and
a controller coupled to said receiver for receiving the input signal, verifying the authenticity and processing said input signal for the particular key activated by the user by invoking the appropriate routine, said controller comprising
a storage means for storing the data generated by said controller responsive to the
input signal corresponding to the first enabling key;
a control module for retrieving the data from the storage means and displaying
said data on the on screen display of the display device.
a timer for setting time frame of a display bar.
2. A system as claimed in claim 1, wherein the external device is a remote control or keyboard.
3. A system as claimed in claim 1, wherein the display is a channel in the display device.
4. A system as claimed in claim 1, wherein the first enabling key is a switching key for
minimizing at least one channel.
5. A system as claimed in claim 1, wherein the second enabling key is a switching key for
selecting the minimized channel according to the user preference.

6. A system as claimed in claim 1, wherein the output key is a switching key for maximizing
the minimized channel.
7. A system as claimed in claim 1, wherein the display bar comprising at least one minimized
channel.
8. A system as claimed in claim 1, wherein the storage means is EEPROM,
9. A system as claimed in claim 1, wherein the on screen display comprising
a display menu for displaying the minimized channels.
a select module for minimizing a channel and closing a minimized channel;
a setting module for setting the time frame of the display bar.
10. A method for switching between displays comprising the steps of:
generating at least one input signal corresponding to a key activated by a user by
an external device;
receiving said input signal by an infrared receiver;
verifying the authenticity of the input signal and processing said input signal for a
particular key by a controller;
storing the data generated by the controller responsive to the input signal
corresponding to the first enabling key in a storage means;
retrieving the data from the storage means by a control module;
displaying said data on a on screen display; and
setting time frame of a display bar by a timer,
11. A method as claimed in claim 10, wherein the display is a channel in the display device.
12. A method as claimed in claim 10, wherein the external device generates a first input signal
corresponding to a first enabling key for minimizing at least one channel.

13. A method as claimed in claim 10, wherein the external device generates a second input
signal corresponding to a second enabling key for selecting the minimized channel
according to the user preference.
14. A method as claimed in claim 10, wherein the external device generates a third input
signal corresponding to an output key for maximizing the minimized channel.
15. A method as claimed in claim 10, wherein, the controller verifies the input signal,
minimizes a channel responsive to the first input signal and adds the minimized channel to
a display bar.
16. A method as claimed in claim 10, wherein, the controller verifies the input signal,
generates at least one control signal responsive to the second input signal for controlling
the corresponding module and for selecting the minimized channel according to the user
preference from the display bar.
17. A method as claimed in claim 10, wherein, the controller verifies the input signal,
maximizes the minimized channel responsive to the third input signal.
18. A method as claimed in claim 10, wherein, the on screen display performs at least one
step for
displaying the minimized channels by a display menu.
minimizing a channel and closing a minimized channel by a select module;
setting the time frame of the display bar by a setting module.
19. A system for switching between displays, substantially as herein described with reference
to the accompanying drawings.
20. A method for switching between displays, substantially as herein described with reference