RECORDING AND REPRODUCING DEVICE OF DIGITAL SIGNAL

摘要

PURPOSE:To attain the recording with high density by making a data recording length on a fixed level after converting every (n) bits of the digital signal into a pulse having changed width with addition of a fixed wavelength and then adding the signal component obtained by subtracting a certain data from the largest information quantity. CONSTITUTION:An analog signal is converted into a digital signal by an A/D converter 2 and supplied to a bit train/bit length converting circuit 3 to be converted into a pulse having the width changed in response to the contents of information every prescribed (n) bits. Then a wavelength lambda0 is added and the data information having the width varying by the information based on the wavelength lambda0 is obtained. This signal is supplied to an optical modulator 6 and recorded in the form of bits. The optical signal of a disk 9 detects the duty of a reproduction signal via an RF signal processing circuit 15 and a reproduction duty correcting circuit 16. Then the duty of the reproduction signal is corrected, and this corrected signal is supplied to a bit length/bit train converting circuit 17. The circuit 17 converts the pulse signal having the width varying in response to the recording information into the digital signal of the original bit train. This digital signal is converted into an analog signal and extracted as a reproduction signal. Thus the recording is possible with high density.