JPS5494291A - Modulating system - Google Patents
Modulating systemInfo
- Publication number
- JPS5494291A JPS5494291A JP56678A JP56678A JPS5494291A JP S5494291 A JPS5494291 A JP S5494291A JP 56678 A JP56678 A JP 56678A JP 56678 A JP56678 A JP 56678A JP S5494291 A JPS5494291 A JP S5494291A
- Authority
- JP
- Japan
- Prior art keywords
- waveform
- pulse train
- modulating signal
- binary
- linear
- 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
Links
Landscapes
- Circuit Arrangement For Electric Light Sources In General (AREA)
- Led Devices (AREA)
Abstract
PURPOSE: To obtain the light output of an LED having been subjected to analog luminance modulation free from non-linear distortions by pulse-density-modulating the analog modulating signal to binary current pulse train of changing densities in proportion to the modulating signal.
CONSTITUTION: The analog modulating signal v(t) of the waveform (a) having been applied to terminal (a) is converted to the binary voltage pulse train of changing densities of pulses in proportion to the modulating signal with a PDM modulator 41. This binary pulse train is converted to a binary current pulse train by a driving circuit 42, which is then applied to a light emitting element (LED) 43, whereby the modulated light output L(t) such as the waveform (c) or (d) is obtained. The current-light converting characteristics of the LED are non-linear but the increase in its light output owing to cumulation of the driving current pulses in the time axis direction is linear and therefore the modulation outputs free from non-linear distortions like the waveform (c) may be obtained. The waveform (d) is neither the waveform having received distortions and may therefore be readily shaped with an LPF or the like after electric conversion on the receiving side. In this way, the system may be readily utilized for optical transmission of analog signals.
COPYRIGHT: (C)1979,JPO&Japio
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP53000566A JPS581555B2 (en) | 1978-01-09 | 1978-01-09 | Modulation method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP53000566A JPS581555B2 (en) | 1978-01-09 | 1978-01-09 | Modulation method |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5494291A true JPS5494291A (en) | 1979-07-25 |
JPS581555B2 JPS581555B2 (en) | 1983-01-11 |
Family
ID=11477257
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP53000566A Expired JPS581555B2 (en) | 1978-01-09 | 1978-01-09 | Modulation method |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS581555B2 (en) |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS50153593A (en) * | 1974-05-29 | 1975-12-10 | ||
JPS51147983A (en) * | 1975-06-14 | 1976-12-18 | Fujitsu Ltd | Driving circuit for light emission diode |
-
1978
- 1978-01-09 JP JP53000566A patent/JPS581555B2/en not_active Expired
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS50153593A (en) * | 1974-05-29 | 1975-12-10 | ||
JPS51147983A (en) * | 1975-06-14 | 1976-12-18 | Fujitsu Ltd | Driving circuit for light emission diode |
Also Published As
Publication number | Publication date |
---|---|
JPS581555B2 (en) | 1983-01-11 |
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