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:
Apr. 25, 1995
Filed:
Oct. 02, 1991
Timothy C Barry, Fremont, CA (US);
John K Martinelli, Paso Robles, CA (US);
Charles E Ader, Concord, CA (US);
Microspeed, Inc., Fremont, CA (US);
Abstract
A trackball device for controlling a cursor on a display screen employs two rotatable shafts and a single nonrotatable support member in contract with the ball to convert rolling motion of the ball to X and Y positioning information. The nonrotatable support member has a number of spaced bearing surfaces and may be removed from and replaced in the trackball housing to present a different bearing surface to the ball, thereby prolonging the life of the device. The device may be provided with removable apertured phase slit members which can be replaced with phase slit members having different apertures therein, to modify the operating resolution of the device.