Title:
LIGHT EMITTING ELEMENT DRIVING CIRCUIT AND LIGHT EMITTING DEVICE HAVING IT
Document Type and Number:
Japanese Patent JP3725235
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To enable the high speed operation, without influence of the noise thereon, when a light emitting element is driven from a positive power source by providing a driving transistor connected to the anode of this element and current adjusting resistance with the cathode of this element connected to the lowest potential.
SOLUTION: A driving transistor 33 is connected to the anode of a light emitting element 31 to feed a pulse current and bias current to this element according to an input signal. A resistor 32 is provided for adjusting the pulse current and bias current of the transistor 33. The cathode of the element 33 is connected to the lowest potential GND. The element 31 is e.g. a semiconductor laser diode of 780nm in wavelength, and the transistor 33 is connected to a positive power source Vcc. A logic circuit 34 is to process and input signal DATA as specified.
Inventors:
Watako Watanabe
Application Number:
JP7794196A
Publication Date:
December 07, 2005
Filing Date:
March 29, 1996
Export Citation:
Assignee:
富士通株式会社
International Classes:
H01S5/00; H01S5/042; H01L33/00; H01S5/06; H05B44/00; (IPC1-7): H01S5/06; H01L33/00
Domestic Patent References:
| JP5950586A | ||||
| JP58190085A | ||||
| JP63285990A | ||||
| JP63312687A | ||||
| JP57171854A | ||||
| JP7240554A |
Foreign References:
| US4182977 |
Attorney, Agent or Firm:
Tadahiko Ito
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