Abstract: A method for measuring a tilt angle of a pickup head. The method includes the steps of: moving the pickup head to a track to be measured; radiating a laser beam with a constant power; defining a proper range of tilt control values; controlling the tilt angle of the pickup head according to the range of tilt control values, acquiring a RF signal corresponding to each tilt control value, and storing an associated value of a associated signal; detecting the maximum among the stored associated values; selecting and storing the tilt control value corresponding to the maximum as the optimum tilt control value for the track if there is a maximum; and modifying the range of tilt control values and executing the previous steps if there is no maximum. The so-called associated signal includes a tracking error signal, a reading/writing RF signal, an S-curve signal, or the RF signal.

Abstract: A method for calibrating tilt control values of a PUH in real time is applied to an optical disk drive and includes the steps of: creating a look-up table, the look-up table including several optical disk data/physical addresses of track zones and the corresponding tilt control values; reading tilt control values as reference values from the look-up table corresponding the track position of a PUH; calculating a current tilt control value according to the reference values; controlling the PUH according to the current tilt control value; reading a decoding error generated during a decoding procedure of the optical disk drive; calibrating the tilt control values and updating the look-up table. When the decoding error is larger than a decoding error threshold, the tilt control values of the track zone is calibrated. Hence, even an irregularly deformed optical disk can be calibrated to obtain better tilt control values.

Abstract: A method for measuring a tilt angle of a pickup head. The method includes the steps of: moving the pickup head to a track to be measured; radiating a laser beam with a constant power; defining a proper range of tilt control values; controlling the tilt angle of the pickup head according to the range of tilt control values, acquiring a RF signal corresponding to each tilt control value, and storing an associated value of a associated signal; detecting the maximum among the stored associated values; selecting and storing the tilt control value corresponding to the maximum as the optimum tilt control value for the track if there is a maximum; and modifying the range of tilt control values and executing the previous steps if there is no maximum. The so-called associated signal includes a tracking error signal, a reading/writing RF signal, an S-curve signal, or the RF signal.

Abstract: A warning light device includes a light member, and a coupling device for coupling the light member to the accelerator pedal of the vehicle, to actuate the light member to generate warning light when the accelerator pedal of the vehicle is released by the drivers, in order to indicate the releasing of the accelerator pedal of the vehicle, and for allowing the following drivers to have a longer time to make responses or to take actions. A rack may be coupled to the accelerator pedal, and a gear may be rotatably engaged onto a spindle of a generator, to actuate the generator to energize the light member when the accelerator pedal is released by the drivers.

Abstract: A method for calibrating a relative tilt angle between a disc and a pickup head using a focus signal. The method includes the steps of moving the pickup head to a first position and performing the focusing operation; obtaining a first variation of a focus signal of the pickup head at a first position; moving the pickup head by a default distance to a second position and performing the focusing operation; obtaining a second variation of the focus signal of the pickup head at a second position; and calculating the relative tilt angle according to the default distance and the first and second variations. The focus signal includes a focus error signal and a focus control signal, both of which have been stored in a control circuit of an optical disc drive. Consequently, the invention utilizes the focus signal to detect the tilt angle of the pickup head without adding any displacement sensor.

Abstract: A method for calibrating tilt control values of a PUH in real time is applied to an optical disk drive and includes the steps of: creating a look-up table, the look-up table including several optical disk data/physical addresses of track zones and the corresponding tilt control values; reading tilt control values as reference values from the look-up table corresponding the track position of a PUH; calculating a current tilt control value according to the reference values; controlling the PUH according to the current tilt control value; reading a decoding error generated during a decoding procedure of the optical disk drive; calibrating the tilt control values and updating the look-up table. When the decoding error is larger than a decoding error threshold, the tilt control values of the track zone is calibrated. Hence, even an irregularly deformed optical disk can be calibrated to obtain better tilt control values.

Abstract: A method for measuring a tilt angle of a pickup head. The method includes the steps of: moving the pickup head to a track to be measured; radiating a laser beam with a constant power; defining a proper range of tilt control values; controlling the tilt angle of the pickup head according to the range of tilt control values, acquiring a RF signal corresponding to each tilt control value, and storing an associated value of a associated signal; detecting the maximum among the stored associated values; selecting and storing the tilt control value corresponding to the maximum as the optimum tilt control value for the track if there is a maximum; and modifying the range of tilt control values and executing the previous steps if there is no maximum. The so-called associated signal includes a tracking error signal, a reading/writing RF signal, an S-curve signal, or the RF signal.

Abstract: An auto gain adjustment apparatus and method are provided for the focusing/tracking control of the optical pickup of an optical disc drive. The gain is obtained by utilizing the self-sustained oscillation from a non-linear component in the optical disc drive, such as a relay circuit with hysteresis. This gain adjustment apparatus and method is more advantageous than the prior art in that the gain can be automatically adjusted without involving manual work and the need to apply an externally generated oscillating test signal. The apparatus and method therefore allows the manufacture and utilization of the optical disc drive to be more efficient and cost-effective.

Abstract: A control device to locate the pickup head on the desired position yielded by the operation of seek is taken in two parts. The first part is utilizing the velocity control to prevent the fluctuation problem of the bi-mass system and the second part is switching the operation to the mode of position control gradually, so that the pickup head can reach the destination precisely and minimize the problem of fluctuation and increase the successful rate of the tracking control. Moreover, this invention has utilized a feedforward control to properly compensate the steady state error originated from the characteristics of system or friction, a position feedback control and a switching factor to gradually switch between the modes of velocity and position. Thus, the position and velocity of the sled motor can be controlled at the same time to allow the pickup head to reach the destination smoothly as expected by the designed of the velocity profile. The tracking control therefore is done smoothly.