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. 05, 1995
Filed:
Jun. 16, 1993
Dennis W Prince, Banks, OR (US);
John K Grosspietsch, Vernon Hills, IL (US);
Benjamin R Clifton, Oregon City, OR (US);
Terry J Scheffer, Portland, OR (US);
In Focus Systems, Inc., Wilsonville, OR (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
The optical response of the pixels of many flat panel display devices, such as liquid crystal displays (2), depends upon the spectral components, as well as the rms value, of the pixel voltage waveform during a frame period. Because each row and column electrode (10 and 11) addresses multiple pixels (14), the spectral voltage components of the voltage across any pixel during a frame period will depend upon the optical state of other pixels in the same column (11). This crosstalk phenomena can be greatly reduced by modifying the addressing signals. One method of modifying the addressing signals is to modulate them so that the spectral components of all pixel voltage waveforms fall primarily in a frequency band (54) in which the optical response is nearly independent of the frequency. Another method is to analyze (220) the spectral components of the pixel voltage waveform over a frame period before it is displayed and adjust (222) the amplitude of the addressing signals to compensate for the frequency dependence of the optical response. When using a gray scale addressing method involving an adjustment factor, such as one based upon virtual pixels (266), the value of each virtual information element (270) is multiplied by a correction factor to compensate for the different frequency components associated with the virtual row.