Video display mode for dual displays

• US 20030179154A1
• Filed: 03/20/2002
• Published: 09/25/2003
• Est. Priority Date: 03/20/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Demsky, Scott H., James, Donald A.
• Granted Patent: US 6,917,348 B2
• Time in Patent Office: Days
• US Class Current: 345/1.1
• CPC Class Codes: G06F 3/1438 using more than one graphics controller

Abstract

A video display controller for controlling images produced at first and second display units, connected respectively to first and second video ports of a computer system, is partitioned into discretely separate first and second video controller elements (VC1 and VC2 respectively), these elements linking respectively to the first and second video ports. In a first mode of operation, termed dual image (DI) mode, these controller elements are conditioned to potentially process different sets of video data, whereby different images are formed at the first and second display units. In a second mode of operation, termed single image (SI) mode, these control elements receive and process a common set of video data so as to form identical images at the first and second display units. In DI mode, video data applied to these controller elements represents portions of a virtual desktop having a display width exceeding the width resolution capabilities of both display units; the portions being constrained to form images within such resolution capabilities. In the same mode, first controller element VC1 is capable of processing video data ranging piecemeal over the entire virtual desktop while second element VC2 is constrained to process data in a fixed portion of the virtual desktop. In a preferred embodiment, the virtual desktop encompasses public and private areas, the private area being useful, for instance, to show private notes associated with matter contained in the public area. Here, VC1 is operated to be able to effectively pan across both areas in increments, whereas VC2 is constrained to process video data associated exclusively with the public area. In this way, a user of the invention making a public presentation could present the public area image to an audience, via VC2 and the second display port, while being able to view portions of both the private and public areas via VC1 and the first display port.

Claims

1. A dual video display controller for a digital computer system having separate first and second video output ports for connecting respectively to first and second video display units, said controller comprising:

a source of video data representing a logical map of a virtual desktop display image having a display resolution width greater than the resolution width capabilities of said display units; and

first and second control elements (VC1 and VC2) capable of receiving portions of said video data defining different parts of said virtual desktop, and for applying received portions respectively to said first and second video output ports;

whereby images of different parts of said virtual desktop are produced at said first and second display units.

2. A dual video controller in accordance with claim 1 wherein said virtual desktop image contains private and public image areas, said private area containing private information intended to be seen only by an immediate user of said computer system and said public area containing information intended for viewing by persons other than said immediate user;

and wherein;

said applied first portion of said video data define a display image spanning parts of both said private and public areas, and said applied second portion of said video data define a display image confined invariably to said public area.

3. A dual video display controller in accordance with claim 2 wherein said first display unit is incapable of displaying the entirety of said virtual desktop image in a single view, and wherein said first control element is adapted to handle said first portions of said video data in varied increments which effectively produce images that pan across the entirety of said virtual desktop.

4. A dual video display controller in accordance with claim 1 having single image (SI) and dual image (DI) modes of operation, wherein:

said video data representing said virtual desktop image is created only while said controller is operated in said DI mode; and

said first and second controller elements, when operated in said SI mode, are adapted to process a common set of video data representing a real desktop image conforming to image width resolution capabilities of both said first and second display units.

5. A dual video display controller in accordance with claim 3 wherein said public and private areas of said virtual desktop are each capable of occupying the entire viewing area of said first display unit;

and

said first controller element is adapted to be able to select portions of said video data so as to create display effects wherein portions of both said private and public areas of said virtual desktop are displayed simultaneously at said first display unit.

6. A program for use in a computer system having first and second video display output ports, said program comprising:

first and second control elements (VC1 and VC2) respectively controlling application of video data to said first and second ports;

said first and second elements being subject to operation independent of each other whereby data applied to said first and second ports may be used to generate different video images.

7. A program in accordance with claim 6 wherein said first and second elements may be operated to produce both different video images and identical video images.