Vtech Electronics Limited

Chi-ming Fong

Kam-chi Chao

Wai-sing Wong

A graphic video display system including at least one graphic layer having sizable, positionable windows and programmable priority values the sprites having fixed priority values. Portions of graphic layer windows and sprites which overlap with a current horizontal scan line of a video display are written to a line buffer. Overlapping objects are resolved by writing portions of objects overlapping the current horizontal scan line to the line buffer in order of the priority values of the objects.

Video display system including graphic layers with sizable, positionable

A scanning apparatus for uniquely identifying an actuated key on a keyboard and an actuated location in a drawing tablet. The scanning apparatus includes independently actuatable switches associated with the keyboard. The scanning apparatus also includes vertical and horizontal conducting traces juxtaposed one to another and electrically connected to a horizontal and vertical resistive bar, respectively, associated with the drawing tablet. The switches and traces are energized under control of the apparatus such that portions of each can be actuated by a user resulting in the generation of unique analog signals indicative of the particular key and particular location upon the drawing tablet actuated by the user. These unique analog signals are converted to digital signals for further processing.

Growing community of inventors

Hong Kong, China

Chi-ming Fong