Optical pickup head and information recording/reproducing device
A technology for information recording and optical pickup, which is applied to optical recording/reproducing, optical recording heads, beam guiding devices, etc., and can solve problems such as inability to read information faithfully, inability to detect TE signals, and uneven light intensity of beam aberrations.
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Embodiment 1
[0077] figure 1 It is a figure which shows the structure of the optical pickup head of Example 1 of this invention.
[0078] A semiconductor laser light source 1 serving as a light source emits a linearly polarized divergent light beam 70 having a wavelength λ1 of 405 nm. The divergent light beam 70 emitted from the semiconductor laser light source 1 is determined by the focal distance f 1 The collimator lens 53 with a diameter of 15 mm converts the parallel light into parallel light, and then enters the diffraction grating 58 to be separated into 3 beams of 0-order diffracted light and ±1-order diffracted light. The 0th-order diffracted light is the main beam 70a for recording / reproducing information, and the ±1st-order diffracted beams are sub-beams 70b and 70c. The sub-beams 70b and 70c are used in the DPP method for stably detecting TE signals. The diffraction efficiency ratio of the 0th-order diffracted light to the 1st-order diffracted light is usually set at 12:1-20:...
Embodiment 2
[0100] The optical pickup of the second embodiment of the present invention has a semiconductor laser light source having a different configuration and arrangement from the optical pickup of the first embodiment. Other configurations are the same as those of the optical pickup head of the first embodiment.
[0101] Example 2 uses a semiconductor laser emitting a light beam with a wavelength of 450 nm or less as a light source. In this case, the substrate constituting the light source and the track on the optical recording medium are arranged so as to be optically parallel.
[0102] The materials used in lasers that emit laser beams with wavelengths below 450nm, such as gallium nitride and zinc selenide, have many lattice defects or weak shielding effects of current and light in the active layer due to self-compensation effects, making it easy to emit light from places other than the light-emitting point. A natural emission light is emitted which may be the cause of tracking t...
Embodiment 3
[0110] The composition of the optical pick-up head of embodiment 3 of the present invention uses Figure 7 to illustrate.
[0111] The light beam 70 with a wavelength of 405nm emitted from the semiconductor laser light source 1 converges on the optical recording medium 41 through the collimator lens 52, the diffraction grating 58, the composite beam shaping prism 4, and the upward mirror 5 with the objective lens 56. On the optical recording medium 41, the main beam 70a, the sub-beam 70b, and the sub-beam 70c corresponding to recording / reproducing are converged. The main beam 70a, the sub-beam 70b and the sub-beam 70c reflected by the optical recording medium 41 are changed by the composite beam shaping prism 4 and enter the beam splitter 16 through the detection lens 59 .
[0112] The beam splitter 16 splits the incident main beam 70a, sub-beam 70b, and sub-beam 70c into two. One of the light beams separated by the beam splitter 16 bends the optical path by approximately 90...
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Abstract
Description
Claims
Application Information
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