Title:
光源装置、投写型表示装置、及び、半導体装置
Document Type and Number:
Japanese Patent JP6988515
Kind Code:
B2
Abstract:
To improve linearity of the optical output from a semiconductor light source to the on-duty ratio of PWM signal by simple circuitry, without using a target value table based on the actual characteristic curve.SOLUTION: A light source device includes a semiconductor light source, a first switching element connected in series with the semiconductor light source, a drive circuit for turning the first switching element on when a PWM signal is activated, a power supply circuit including a second switching element and supplying a current to the semiconductor light source, a current detector for detecting a current flowing to the semiconductor light source and outputting a current detection signal, a compensation circuit generating a compensatory signal having a voltage which changes according to the on-duty ratio of the PWM signal, an adder circuit for adding the current control signal and the compensatory signal at a prescribed ratio, an error amplifier generating an error signal by amplifying the difference of the output signal from the adder circuit and the current control signal, and a power supply control circuit for controlling the power supply circuit on the basis of the error signal.SELECTED DRAWING: Figure 1
Inventors:
Atsushi Yamada
Application Number:
JP2018010296A
Publication Date:
January 05, 2022
Filing Date:
January 25, 2018
Export Citation:
Assignee:
Seiko Epson Corporation
International Classes:
H05B45/325; H01L33/00; H05B45/14
Domestic Patent References:
| JP2017511579A | ||||
| JP2011014828A | ||||
| JP2012118313A | ||||
| JP2014026954A |
Attorney, Agent or Firm:
Satoshi Nakai
Hiroki Matsuoka
Hiroki Matsuoka
Previous Patent: Drive device
Next Patent: Operating status monitoring device, operating status monitoring system, operating status monitoring ...
Next Patent: Operating status monitoring device, operating status monitoring system, operating status monitoring ...