Optical pickup apparatus

An optical pickup apparatus which records or reproduces information on or from an optical recording medium, comprising:

• a light source for emitting light;
• an objective lens opposed to the optical recording medium, for focusing light originating from the light source on the information recording surface of the optical recording medium;
• a light separation optical element disposed between the light source and the objective lens, for transmitting or reflecting the light originating from the light source;
• a collimator lens disposed between the light separation optical element and the objective lens, for converting the light originating from the light source into generally parallel light;
• an optical path changing reflector disposed between the collimator lens and the objective lens, for reflecting the light originating from the light source to change its optical path;
• optical output power detecting means for detecting part of light that is emitted from the light source, passes through the collimator lens, and goes by the optical path changing reflector instead of shining on it;
• and
• optical power control means for controlling the power of the light emitted from the light source in accordance with a detection output of the optical output power detecting means.

An optical pickup apparatus which records or reproduces information on or from an optical recording medium by using light, comprising:

• a light source for emitting light;
• light detecting means for detecting part of the light emitted from the light source;
• light collecting means for directing, to the light detecting means, part of the light emitted from the light source that is not used for information recording or reproduction;
• and
• control means for controlling the power of the light emitted from the light source in accordance with an output of the light detecting means.

An optical pickup apparatus which records or reproduces information on or from an optical recording medium by using light, comprising:

• a light source for emitting light;
• light detecting means for detecting part of the light emitted from the light source;
• light separating means for separating part of the light emitted from the light source that is to be used for information recording or reproduction and directing, to the light detecting means, the part of the light;
• and
• control means for controlling the power of the light emitted from the light source in accordance with an output of the light detecting means.

An optical pickup apparatus which records or reproduces information on or from an optical recording medium by using light, comprising:

• a light source for emitting light;
• light reflecting means for reflecting part of the light emitted from the light source that is not used for information recording or reproduction;
• monitoring light detecting means for detecting the light reflected from the light reflecting means;
• control means for controlling the power of the light emitted from the light source in accordance with a detection output of the monitoring light detecting means;
• focusing means for focusing light that originates from the light source and is used for information recording or reproduction on the information recording surface of the optical recording medium;
• and
• light detecting means for detecting light reflected from the optical recording medium.