专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

1. 发明专利

JPH1040007A POSITION READING DEVICE 失效
公开(公告)号：JPH1040007A
公开(公告)日：1998-02-13
申请号：JP19433696
申请日：1996-07-24
申请人： HITACHI LTD , HITACHI VIDEO IND INF SYST INC
发明人： SAKAI YASUO , TSUREDA YUTAKA , SUZUKI TETSUYA
IPC分类号： G06F3/041 , G06F3/033
摘要： PROBLEM TO BE SOLVED: To attain highly precise reading by level-fixing the driving signal of a display device among display control signals, preventing a noise component from mixing into the output signal of a tablet, and creating position information. SOLUTION: A position reading period signal generating circuit 9 counts a horizontal scanning signal, compares the counted value with a value preliminarily set by a CPU 1, and supplies a position reading period signal 108 to a signal fixing circuit 8 and a period informing circuit 10 as a low level output when the counted value is turned into the set value. Then, the signal fixing circuit 8 fixes the level of a display data transfer signal and a horizontal scanning signal in the scanning period of a position reading area so that the level changing point of the horizontal scanning signal and the signal changing point of a liquid crystal alternating signal can not be generated. Thus, a noise in the scanning period of the position reading area can be completely evaded and the highly precise position reading can be attained.

IPRDB