JPS56153786A - Monitoring circuit for bias current of laser-diode - Google Patents
Monitoring circuit for bias current of laser-diodeInfo
- Publication number
- JPS56153786A JPS56153786A JP5618180A JP5618180A JPS56153786A JP S56153786 A JPS56153786 A JP S56153786A JP 5618180 A JP5618180 A JP 5618180A JP 5618180 A JP5618180 A JP 5618180A JP S56153786 A JPS56153786 A JP S56153786A
- Authority
- JP
- Japan
- Prior art keywords
- comparator
- output
- temperature
- diode
- set value
- 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.)
- Pending
Links
Landscapes
- Semiconductor Lasers (AREA)
Abstract
PURPOSE: To enable to monitor bias currents under a binary system of the output of a comparator by a method wherein a temperature sensing circuit is mounted which changes following the temperature characteristics of a laser diode, and the output of the temperature sensing circuit is forwarded to the comparator.
CONSTITUTION: When the temperaure of a laser diode LD changes to a low temperature from a high temperature, the resistance value of a sensor 2 increases. Thus, when bias current Io is within a proper value, the input of a comparator II is kept within a set value. Consequently, a LED4 of a normal condition displaying section III emits light. When the currents Io exceed the proper value, on the other hand, the input of the comparator II also exceeds the set value. as a result, the LED7 of an abnormal condition displaying section IV emits light. In this case, a bias circuit of the diode LD decreases the current Io because a feedback circuit flowing the proper currents Io in response to temperature is installed, thus hardly changing the output of a temperature sensing circuit I, then keeping the output within the set value. Accordingly, the quality of a function of the feedback circuit can be determined by monitoring the adequacy of the Io current.
COPYRIGHT: (C)1981,JPO&Japio
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5618180A JPS56153786A (en) | 1980-04-30 | 1980-04-30 | Monitoring circuit for bias current of laser-diode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5618180A JPS56153786A (en) | 1980-04-30 | 1980-04-30 | Monitoring circuit for bias current of laser-diode |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS56153786A true JPS56153786A (en) | 1981-11-27 |
Family
ID=13019929
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5618180A Pending JPS56153786A (en) | 1980-04-30 | 1980-04-30 | Monitoring circuit for bias current of laser-diode |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS56153786A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58107692A (en) * | 1981-12-21 | 1983-06-27 | Konishiroku Photo Ind Co Ltd | Protecting method for semiconductor laser |
| JPS61100162U (en) * | 1984-12-07 | 1986-06-26 | ||
| JPS61143053A (en) * | 1984-12-17 | 1986-06-30 | 富士電機株式会社 | Laser medical device |
| JPS6282758U (en) * | 1985-05-10 | 1987-05-27 | ||
| JPS62146012A (en) * | 1985-12-20 | 1987-06-30 | Omron Tateisi Electronics Co | Photoelectric switch |
| JPH02122463U (en) * | 1989-03-20 | 1990-10-08 | ||
| JPH04334078A (en) * | 1991-05-10 | 1992-11-20 | Fujitsu Ltd | Semiconductor laser controlling equipment |
| JP2002076506A (en) * | 2000-08-30 | 2002-03-15 | Nec Corp | Method and device for detecting abnormality of optical module |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52123185A (en) * | 1976-04-09 | 1977-10-17 | Fujitsu Ltd | Optical communication supervisory system |
-
1980
- 1980-04-30 JP JP5618180A patent/JPS56153786A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52123185A (en) * | 1976-04-09 | 1977-10-17 | Fujitsu Ltd | Optical communication supervisory system |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58107692A (en) * | 1981-12-21 | 1983-06-27 | Konishiroku Photo Ind Co Ltd | Protecting method for semiconductor laser |
| JPS61100162U (en) * | 1984-12-07 | 1986-06-26 | ||
| JPS61143053A (en) * | 1984-12-17 | 1986-06-30 | 富士電機株式会社 | Laser medical device |
| JPS6282758U (en) * | 1985-05-10 | 1987-05-27 | ||
| JPS62146012A (en) * | 1985-12-20 | 1987-06-30 | Omron Tateisi Electronics Co | Photoelectric switch |
| JPH02122463U (en) * | 1989-03-20 | 1990-10-08 | ||
| JPH04334078A (en) * | 1991-05-10 | 1992-11-20 | Fujitsu Ltd | Semiconductor laser controlling equipment |
| US5334826A (en) * | 1991-05-10 | 1994-08-02 | Fujitsu Limited | Method and apparatus for extending and confirming the service life of semiconductor laser of bar code reader by detecting current increase corresponding to temperature of semiconductor laser |
| JP2002076506A (en) * | 2000-08-30 | 2002-03-15 | Nec Corp | Method and device for detecting abnormality of optical module |
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