Abstract: A solar cell structure includes a semiconductor substrate having a front side and a back side. A pyramid structure is disposed on the front side of the semiconductor substrate. The pyramid structure has an aspect ratio between 0.5-1.2. A front passivation layer is disposed on the pyramid structure. A first anti-reflection layer is disposed on the pyramid structure. The first anti-reflection layer is a multi-layered, graded anti-reflection layer having at least three coating layers. The at least three coating layers comprise a silicon oxynitride layer having a thickness of 15-30 nm and a refractive index between 1.65 and 1.75. The silicon oxynitride layer is an outermost layer of the multi-layered, graded anti-reflection layer.

Abstract: A solar cell structure includes a semiconductor substrate having a front side and a back side; a pyramid structure disposed on the front side of the semiconductor substrate; a front passivation layer disposed on the pyramid structure; and a first anti-reflection layer disposed on the pyramid structure. The first reflective layer is a multi-layered anti-reflection layer having at least three coating layers. A front electrode is provided on the first anti-reflection layer. A rear passivation layer is provided on the back side of the semiconductor substrate. A second anti-reflection layer is disposed on the rear passivation layer. A back electrode is disposed on the second anti-reflection layer.

Abstract: A solar cell structure includes a semiconductor substrate having a front side and a back side; a pyramid structure disposed on the front side of the semiconductor substrate; a anti-reflection layer disposed on the pyramid structure; a front electrode provided on the anti-reflection layer; a passivation layer provided on the back side of the semiconductor substrate; a dielectric layer disposed on the passivation layer; and a back electrode disposed on the dielectric layer. The reflective layer is a multi-layer anti-reflection layer having at least three coating layers.

Abstract: A controller and a control method is provided to control a spherical aberration correcting device provided in an optical pick-up head to change a spherical aberration compensate value according to different controlling states during the spherical aberration correcting device changes the spherical aberration compensate value. For the mechanical type spherical aberration correcting device, the controlling states are the different speeds for the actuators to drive the lenses. For the liquid crystal type spherical aberration correcting device, the controlling states are the control values for the driver to drive liquid crystal spherical aberration corrector.

Abstract: A laser power control unit used for controlling the laser power of an optical pick-up unit (OPU) is provided. The laser power control unit includes: at least one analog-to-digital converter (ADC) electrically coupled to the OPU for transferring a front photodiode output signal into a digital feedback signal; and at least one digital control circuit electrically coupled to the ADC for generating a power control signal and outputting the power control signal to the OPU in order to control the laser power of the OPU. The digital control circuit has a compensation circuit used for generating a compensation value according to a difference between the digital feedback signal and a digital target feedback signal so as to adjust the power control signal. The front photodiode output signal corresponds to the laser power of the OPU.

Abstract: A method of identifying an optical disc is disclosed. The method includes enabling an optical pick-up unit to emit a first laser beam having a first wavelength to the optical disc; controlling the optical pick-up unit to move a focus point of the first laser beam in a direction of thickness of the optical disc; obtaining a first focus error (FE) signal corresponding to the first laser beam; counting a first s-curve number corresponding to s-curve occurring in the first FE signal; and identifying the optical disc according to the first s-curve number.

Abstract: A device for canceling a land-groove offset component of a focusing error signal in an optical storage system includes first and second circuits, and an adder. The first circuit processes a radio (or wobble) frequency ripple signal to obtain a first processed signal that is multiplied by a first gain value (G1) so as to result in a first signal. The second circuit processes a tracking error signal to obtain a second processed signal that is multiplied by a second gain value (G2) so as to result in a second signal. The adder is coupled to the first and second circuits, and adds the first and second signals to produce a compensative land-groove offset component that is to be fed into a focusing device of the optical storage system so as to enable the focusing device to cancel out the land-groove offset component of the focusing error signal.

Abstract: A laser power control unit used for controlling the laser power of an optical pick-up unit (OPU) is provided. The laser power control unit includes: at least one analog-to-digital converter (ADC) electrically coupled to the OPU for transferring a front photodiode output signal into a digital feedback signal; and at least one digital control circuit electrically coupled to the ADC for generating a power control signal and outputting the power control signal to the OPU in order to control the laser power of the OPU. The digital control circuit has a compensation circuit used for generating a compensation value according to a difference between the digital feedback signal and a digital target feedback signal so as to adjust the power control signal. The front photodiode output signal corresponds to the laser power of the OPU.

Abstract: A laser power controller for performing an auto power control to control the laser power of an optical pick-up unit (OPU) includes: a sample/hold circuit used for sampling and holding a front photodiode output signal to generate an analog feedback signal; an analog-to-digital converter (ADC) electrically coupled to the sample/hold circuit for transferring the analog feedback signal into a digital feedback signal; and a digital control circuit electrically coupled to the ADC for generating a power control signal and outputting the power control signal to the OPU in order to control the laser power of the OPU. The front photodiode output signal corresponds to the laser power of the OPU.

Abstract: An optical disc drive includes a spindle motor and a computer program. The spindle motor is adapted for rotating an optical disc. The computer program configures the optical disc drive to perform consecutive steps of a method for detecting eccentricity of the optical disc, including: a) while the optical disc drive operates under focused and track-locked conditions, controlling the spindle motor to rotate the optical disc at a specified rotation speed; b) measuring an eccentricity value of the optical disc being rotated by the spindle motor; and c) comparing the eccentricity value measured in step b) with a reference value to determine extent of eccentricity of the optical disc.

Abstract: A laser power controller for performing an auto power control to control the laser power of an optical pick-up unit (OPU) includes: a sample/hold circuit used for sampling and holding a front photodiode output signal to generate an analog feedback signal; an analog-to-digital converter (ADC) electrically coupled to the sample/hold circuit for transferring the analog feedback signal into a digital feedback signal; and a digital control circuit electrically coupled to the ADC for generating a power control signal and outputting the power control signal to the OPU in order to control the laser power of the OPU. The front photodiode output signal corresponds to the laser power of the OPU.

Abstract: A device for canceling a land-groove offset component of a focusing error signal in an optical storage system includes first and second circuits, and an adder. The first circuit processes a radio (or wobble) frequency ripple signal to obtain a first processed signal that is multiplied by a first gain value (G1) so as to result in a first signal. The second circuit processes a tracking error signal to obtain a second processed signal that is multiplied by a second gain value (G2) so as to result in a second signal. The adder is coupled to the first and second circuits, and adds the first and second signals to produce a compensative land-groove offset component that is to be fed into a focusing device of the optical storage system so as to enable the focusing device to cancel out the land-groove offset component of the focusing error signal.

Abstract: An optical disc drive includes a spindle motor and a computer program. The spindle motor is adapted for rotating an optical disc. The computer program configures the optical disc drive to perform consecutive steps of a method for detecting eccentricity of the optical disc, including: a) while the optical disc drive operates under focused and track-locked conditions, controlling the spindle motor to rotate the optical disc at a specified rotation speed; b) measuring an eccentricity value of the optical disc being rotated by the spindle motor; and c) comparing the eccentricity value measured in step b) with a reference value to determine extent of eccentricity of the optical disc.