METHOD AND APPARATUS FOR
CHANGING THE MODE OF A DISPLAY
CROSS REFERENCE TO RELATED 5
The present invention claims priority under 35 U.S.C. § 120 as a continuation of 09/406,931 now U.S. Pat. No. 6,326,935, filed Sep. 28, 1999, which is herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates generally to computer systems and, more particularly, to display devices for use with 15 computer systems such as personal computer systems.
BACKGROUND OF THE INVENTION
Personal computer systems, such as IBM personal computer systems, have attained widespread use. Historically, such systems have been information handling systems designed primarily to give independent computing power to a single user (or a relatively small group of users in the case of personal computers which serve as computer server systems).
Convergence products are now beginning to form a relatively new category of entertainment products, based on the convergence of personal computer (PC) technology and traditional consumer electronics technology. With this trend towards convergence, or using a personal computer with a large monitor as the heart an entertainment system, it is likely that standards will eventually be developed to assure the compatibility and interoperability of products. However, conventional interlaced television (broadcast and cabled) is still currently a widespread viable medium. Even if such standards are eventually developed, there will exist a very large number of "legacy" consumer electronic devices that users may wish to continue using, along with a large number of existing articles containing analog video information in well-established formats. Therefore, even if a computer is employed in an entertainment system, it is likely that users will wish to continue to view conventional (interlaced) video from sources such as broadcast and cabled television, inputs from other analog video sources such as videotape recorders (VTRs), laser disk players, video camcorder devices, and so forth.
It is known to receive an interlaced video source and convert it to a noninterlaced VGA format for display on a computer monitor. In so doing, it is also known to switch the monitor between an overscanned "TV mode" with increased brightness and altered color temperature for employing a computer monitor to view television content, and an underscanned"computer graphics mode" which generally has decreased brightness and sharper focus for viewing computer graphics content. However, even in television mode, the interlaced signal is not displayed directly, but is converted to a VGA signal.
Combination television/computer monitors are also known which are capable of displaying both a VGA (noninterlaced) signal and which further contain standard television tuning electronics. Although such devices may be interfaced to a computer, they are switched between the television and computer graphics modes only via the television-user interface, i.e., buttons or switches on the television itself or via a remote control television interface. Similarly, once the television mode has been selected, there
does not exist any method for controlling the traditional television features, such as channel selection, via the host computer. Therefore, there exists a need for a system and method for switching between the computer (noninterlaced) and television (interlaced) of such TV/monitor hybrid displays from a host computer system interface. There also exists a need for a method and system for controlling traditional television features from a host computer system interface.
SUMMARY OF THE INVENTION
In one aspect, the present invention provides a display apparatus for use with a host computer system, wherein the display apparatus is of the type capable of a television (interlaced) mode of operation mode and a computer (non interlaced) mode of operation. Displays capable of both types of operation are generally known in the art. As used herein, the terms television mode and interlaced mode will refer to an interlaced mode of display operation with any other modifications for optimizing the viewing of a television signal, such as overscanning, increasing brightness, changing the color temperature, and so forth. As used herein, the terms computer graphics mode and noninterlaced mode refer to a progressively scanned computer graphics mode of operation which is typically underscanned and generally is less bright and more sharply focused than the television mode of operation.
The display apparatus according to the present invention comprises a screen which is operable to display in a visually detectable manner output from the host computer system when operating in the interlaced mode of operation and which is further operable to display a television compatible signal such as an NTSC signal when operating in the noninterlaced mode of operation. The display apparatus further comprises a communication channel for transmitting commands from the host computer system to the display apparatus. The display apparatus contains a microprocessor for receiving commands from the host computer system, the microprocessor comprising control logic for switching the display between the interlaced and noninterlaced modes of operation.
In one embodiment, the communication channel between the display apparatus and the host system also allows the host system to control, in addition to the display mode, additional TV functions, such as changing channels, selecting a video source, making volume and picture adjustments, and so forth.
In another aspect, the present invention provides a computer system comprising a host computer system which comprises a processor, a memory coupled to the processor, a video controller coupled to the processor and memory, and the video display apparatus in accordance with the present invention as described herein.
In another aspect, the present invention provides a method of operating a computer system to control a display apparatus, the display apparatus coupled to a video controller of a host computer system. The computer system and display apparatus are coupled via a communication channel and the display apparatus comprises circuitry providing a first mode of operation and a second mode of operation, wherein the first mode of operation is one of an interlaced mode of operation and a noninterlaced mode of operation and wherein the second mode of operation is the other. The method according to the present invention comprises operating the display in the first display mode, receiving user input to change the display mode from the first mode to the