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:
Jan. 14, 1992
Filed:
Oct. 17, 1989
Yoriyuki Takekawa, Higashimatsuyama, JP;
Hidekazu Oshizawa, Higashimatsuyama, JP;
Diesel Kiki Co., Ltd., Tokyo, JP;
Abstract
A display system for a vehicle is provided with a fluorescent display tube. An anode control circuit outputs a control signal for selecting one or more of anode electrodes of the display tube to output a first control signal in response to which the selected anode electrodes are supplied with a positive voltage to cause the flourescent display tube to make a display. A display condition judging circuit judges whether or not the anode control circuit is outputting the first control signal. A brightness judging circuit judges whether the surroundings of the fluorescent display tube are bright or dark. A filament control circuit outputs a second control signal for energizing a filament of the display tube when said display condition judging circuit judges that the anode control circuit is outputting the first control signal and/or when the brightness judging circuit judges that the surroundings of the display tube are bright. The filament control circuit ceases to output the second control signal when the anode control circuit does not output the first control signal and at the same time when the brightness judging circuit judges that the surroundings of the display tube are dark.