Optical data recording/reproducing apparatus

A data recording/reproducing apparatus comprising:

• light source means for emitting write laser light and read laser light;
• high frequency (HF) oscillating means, connected to said light source means, for supplying an HF signal for reducing laser noise to said light source means;
• a shield case for housing said light source means and said HF oscillating means;
• write driving means for supplying a write drive signal to said light source means through a write line;
• read driving means for supplying a read drive signal to said light source means through a read line provided independently of said write line in at least said shield case;
• undesired radiation preventing means, connected to said read line, for preventing undesired radiation of the HF signal from said HF oscillating means;
• and
• control means for making a circuit constant of said undesired radiation preventing means in a write mode differ from a circuit constant in a read mode.

A data recording/reproducing apparatus comprising:

• first light source means for emitting write laser light;
• second light source means for emitting read laser light;
• high frequency (HF) oscillating means, connected to said second light source means, for supplying an HF signal for reducing laser noise to said second light source means;
• a shield case for housing said second light source means and said HF oscillating means;
• and
• filter means, connected to a drive line of said second light source means in said shield case, for preventing transmission of the HF signal from said HF oscillating means to outside said shield case.

A data recording/reproducing apparatus comprising:

• light source means for outputting data write laser light with a variable intensity and data read laser light with a fixed intensity;
• high frequency (HF) oscillating means for superposing an HF signal on a drive signal for said light source means;
• a shield case for housing said HF oscillating means to prevent propagation of noise of the HF signal;
• driving means, arranged outside said shield case, for generating the drive signal for said light source means;
• HF cutoff filter means having a coil arranged inside said shield case on a signal line connecting said driving means and said light source means;
• and
• control means for controlling an inductance of said coil such that an inductance in a write mode is smaller than an inductance in a read mode.