JPH03232283A - Semiconductor laser drive circuit - Google Patents

Semiconductor laser drive circuit

Info

Publication number
JPH03232283A
JPH03232283A JP2029098A JP2909890A JPH03232283A JP H03232283 A JPH03232283 A JP H03232283A JP 2029098 A JP2029098 A JP 2029098A JP 2909890 A JP2909890 A JP 2909890A JP H03232283 A JPH03232283 A JP H03232283A
Authority
JP
Japan
Prior art keywords
laser diode
ldinh
forced stop
circuit
forced
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2029098A
Other languages
Japanese (ja)
Other versions
JP2965596B2 (en
Inventor
Yukio Yoshikawa
Takeshi Ishii
Yoshihiro Oyama
Shinichi Sato
Kazumasa Moriya
Original Assignee
Copal Co Ltd
Fujitsu Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Copal Co Ltd, Fujitsu Ltd filed Critical Copal Co Ltd
Priority to JP2029098A priority Critical patent/JP2965596B2/en
Priority claimed from US07/650,422 external-priority patent/US5163063A/en
Publication of JPH03232283A publication Critical patent/JPH03232283A/en
Application granted granted Critical
Publication of JP2965596B2 publication Critical patent/JP2965596B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Abstract

PURPOSE: To obtain a semiconductor laser drive circuit excellent in safety by a method wherein at least two or more forced quenching circuits independent of each other are provided.
CONSTITUTION: A semiconductor laser drive circuit is composed of a current feed circuit which supplies a drive current to a laser diode 1a responding to a lighting signal LDON to start it emitting light, a first forced quenching circuit which stops feeding a drive current to the laser diode 1a to forcedly turn off it responding to a forced stop signal LDINH 1, and a second forced stop circuit which responds to a forced stop signal LDINH 2. When an emergency occurs, the forced stop signal LDINH 1 is made to turn high in level, a transistor 12 becomes non-conductive, the second forced stop signal LDINH 2 is made to turn low in level, a transistor 15 becomes conductive, a voltage between the anode and the cathode of the laser diode 1a becomes smaller than a forward voltage, a current fed from a power supply line Vcc is made to flow through a transistor 15 bypassing the laser diode 1a, so that the laser diode 1a is forcedly turned OFF.
COPYRIGHT: (C)1991,JPO&Japio
JP2029098A 1990-02-07 1990-02-07 Semiconductor laser drive circuit Expired - Fee Related JP2965596B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2029098A JP2965596B2 (en) 1990-02-07 1990-02-07 Semiconductor laser drive circuit

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2029098A JP2965596B2 (en) 1990-02-07 1990-02-07 Semiconductor laser drive circuit
US07/650,422 US5163063A (en) 1990-02-07 1991-02-04 Semiconductor laser driving circuit
EP19910400295 EP0441709B1 (en) 1990-02-07 1991-02-07 Semiconductor laser driving circuit
DE1991622140 DE69122140T2 (en) 1990-02-07 1991-02-07 Driver circuit for semiconductor lasers

Publications (2)

Publication Number Publication Date
JPH03232283A true JPH03232283A (en) 1991-10-16
JP2965596B2 JP2965596B2 (en) 1999-10-18

Family

ID=12266878

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2029098A Expired - Fee Related JP2965596B2 (en) 1990-02-07 1990-02-07 Semiconductor laser drive circuit

Country Status (1)

Country Link
JP (1) JP2965596B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014524046A (en) * 2011-06-29 2014-09-18 マイクロビジョン,インク. Scanning laser projector with safety system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100158055A1 (en) * 2008-12-18 2010-06-24 Symbol Technologies, Inc. Method and apparatus for controlling and monitoring laser power in barcode readers

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014524046A (en) * 2011-06-29 2014-09-18 マイクロビジョン,インク. Scanning laser projector with safety system

Also Published As

Publication number Publication date
JP2965596B2 (en) 1999-10-18

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