| 摘要 |
PROBLEM TO BE SOLVED: To eliminate pulse width errors which occurs, when remote control signals are demodulated from infrared-ray carrier signals. SOLUTION: An infrared-ray receiving section 201 receives infrared-ray carrier signals from an infrared-ray remote controller 100 and an infrared-ray carrier demodulating section 202 demodulates remote control signals, by integrating the received signals by means of an integration circuit composed of a capacitor and a resistor. When the section 202 demodulates the remote control signals, an error is produced in the pulse width of the demodulated remote control signals, because the discharge from the capacitor continues, even if the pulse of the remote control signals becomes low level signals. A waveform correcting section 203 for the remote control signals integrates the remote control signals with a long time constant in the forefront section of the pulse of the remote control signals from the demodulating section 202 and with a short time constant in the terminal section of the pulse. Then the section 203 shapes the waveform of the remote control signals into a rectangular waveform, depending on the integrated results, that is, whether the results are higher than a reference level. Since the remote control signals are integrated with the long time constant in the forefront section of the pulse, such an error is eliminated. |
