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:
Mar. 30, 1999
Filed:
Dec. 11, 1996
Keiichi Hayashi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
Data communications are carried out between portable information terminals through infrared radiation with an energy source which may be either a battery in each of the portable information terminals or an external power supply therefor, at a data transmission rate which is relatively low when the portable information terminal is operated by the battery. If the power source is the incased battery, the data transmission rate is switched to a low rate, data to be transmitted are compressed, and the respective numbers of bits '0' and '1' contained in the compressed data are compared with each other. If the number of bits which require a greater amount of electric energy for transmission is greater than the other number of bits, then the value of bits is inverted. Data indicative of the low data transmission rate, the compression of the data, and whether the value of bits has been inverted or not are coded into header data which are added to the compressed data for transmission. The data transmission rate is adjusted, the compressed data are expanded, and the inverted value of bits is inverted back by a controller in response to the header data at the receiver side.