Scanning display driver
US5831639A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 5, 1995 |
| Grant date | Nov 3, 1998 |
| Priority date | — |
| Expiry date | Jul 5, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2310/04
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A remote control program (230) includes a scanning display driver (232) that interacts with the graphics display driver (112) of a host computer (110) to provide to the display (122) of the remote computer (120) an image (117) generated on the display (116) of the host computer (110). The scanning display driver (232) employs device independent function calls to the GDI (112) of the host computer (110) to eliminate any hardware dependent artifacts from the remote computer display (122). A scanning module (234) in the scanning display driver (112) retrieves bit map segments (119) of the image (117) on the host display (116), calculates a checksum value for comparison with a stored checksum value (542), updates the stored value (542) when the bit map segment (119) has been changed, and sets a flag (544) to indicate a new checksum value has been stored. An update module (236) scans the flags (544) and operates in conjunction with a communication module (240) to transfer changed bit map segments (119) to the remote computer (120). Transferred bit map segments (129) are stored in the remote computer (120) and used to refresh the image (127) on the remote display (122) until a new checks…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.