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. 15, 2008
Filed:
Oct. 21, 2004
Hiroaki Itoh, Kashihara, JP;
Naruichi Yokogawa, Kashihara, JP;
Takeshi Nishino, Nara, JP;
Ryosuke Kawashima, Katsuragi, JP;
Hiroaki Itoh, Kashihara, JP;
Naruichi Yokogawa, Kashihara, JP;
Takeshi Nishino, Nara, JP;
Ryosuke Kawashima, Katsuragi, JP;
Sharp Kabushiki Kaisha, Osaka-shi, JP;
Abstract
An infrared transmitter circuit causes an output current to flow to a light emission diode via a current mirror circuit constituted of three transistors by using a current supplied from a power source circuit, so that the light emission diode emits light. When a voltage Vvaried by charging a capacitor with a current flowing from the power source circuit exceeds a reference voltage (voltage V), an output of a comparator resets a D flip-flop, so that an output of the D flip-flop varies to '0'. Thus, an output of a NAND gate to which that output and a transmission signal are inputted causes a transistor (N-channel FET) to turn ON so as to stop operation of the current mirror circuit, and causes a transistor (P-channel FET) to turn OFF so as to cut a connection between the power source circuit and a power source line. Thus, it is possible to reduce power consumption in operation of a protection circuit which stops supplying the output current to the light emission diode.