The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 15, 1992
Filed:
Mar. 15, 1991
Hitachi, Ltd., Tokyo, JP;
Abstract
In the case where a map is used as a figure upon vertical scrolling for enlarging or reducing a map having a predetermined accuracy, a map having a higher accuracy as well as a map having a less amount of graphic data are subjected to vertical scrolling so that the map having a lower accuracy or the less amount of data is displayed superposing on the map having the higher accuracy. Upon vertical scrolling, the speed of vertical scrolling is improved in such a manner that the brightness of one of the maps which is gradually reduced is decreased to an extent in which a positional relation of the one map with the other map which is gradually enlarged is not unrecognizable to an operator and the one map displayed with a predetermined size is erased from a display device when the brightness of the one map is decreased to zero. Even in the case where the above-mentioned vertical scrolling and horizontal scrolling are used in combination, the scrolling is made with an improved speed. In the case where a three-dimensional figure is to be subjected to horizontal scrolling, a two-dimensional version of the three-dimensional figure from which information of height is eliminated is subjected to visual-point conversion and the visual-point converted two-dimensional figure is used upon horizontal scrolling, thereby improving the speed of horizontal scrolling.