Patent application number | Description | Published |
20090135686 | OFFSET COMPENSATION METHOD FOR LASER POWER CONTROL CIRCUIT - A method for compensating the offset of a laser power control circuit, which predetermines a fixed reference voltage, adjusts the offset voltage by adding the reference voltage, outputs a summed voltage to a pick-up head, tries to ignite the pick-up head, detects the voltage of the pick-up head, checks whether the detected voltage rises to a specific threshold voltage, continues adjusting the offset voltage if the detected voltage has not risen to the specific threshold voltage and records the offset voltage if the detected voltage has risen to the specific threshold voltage, and configures the offset voltage to be the voltage offset compensation for the laser power control circuit, thereby eliminating feature differences of different pick-up heads of the laser power control circuit. | 05-28-2009 |
20090135697 | METHOD FOR DISTINGUISHING OPTICAL DISCS - The invention is to provide a method for distinguishing optical discs, which first locks a focus on a data layer of an optical disc to cross the grooves and the lands of the optical disc, then starts testing and counting the time for testing, records a detected RF signal, checks if the time for testing reaches a predetermined time, continues locking the focus on the data layer to test if it has not, finds out the maximum intensity of the detected RF signal among the recorded RF signals, and compares the maximum intensity of the detected RF signal with the parameters regarding formats of optical discs previously stored in order to correctly distinguish the optical disc. | 05-28-2009 |
20100157767 | METHOD FOR IDENTIFYING AN ABNORMAL DISC - A method for identifying an abnormal disc includes the steps of: forming three testing spherical aberration (SA) values including an SA value of a thinner data layer, a standard SA value and an SA value of a thicker data layer; adjusting to one of the testing SA values; performing focus for a target disc and recording a focus error signal; obtaining a maximum focus error signal and a corresponding testing SA value by way of comparison; and checking whether the corresponding testing SA value is equal to the standard SA value, and identifying the target disc as a normal disc if yes, or otherwise identifying the target disc as the abnormal disc and re-adjusting the SA value to enhance the signal quality. | 06-24-2010 |
20100177606 | METHOD FOR IDENTIFING A LAYER NUMBER OF AN OPTICAL DISC - A method for identifying a layer number of an optical disc is provided. Firstly, a SA value is adjusted to a standard SA value of each of two data layers in sequence. Next, focusing courses are performed so as to enable the focus point to pass through the optical disc. Then, maximum amplitudes of focusing error signals in the focusing courses are recorded. After that, whether the maximum amplitudes of the focusing error signals recorded in the focusing courses are equal is checked. If the maximum amplitudes are equal, the optical disc is identified as a double-layered disc. If the maximum amplitudes are not equal, the optical disc is identified as a single-layered disc. | 07-15-2010 |
Patent application number | Description | Published |
20090135695 | Method of detecting an abnormal disc - A method of detecting an abnormal disc is provided. Firstly, an objective lens is moved along a one-way path for enabling the light beam of the objective lens to pass through the data layer of a disc. Next, the path having RF signal is detected and recorded. Then, whether the terminal of the one-way path is reached is determined: if the terminal is not reached, the method continues to move the objective lens; if the terminal is reached, the method calculates the length of vibration path on which RF signal is detected. After that, whether the length of vibration path is larger than a path threshold is determined: if the length of vibration path is not larger than a path threshold, the disc is a normal disc; if the length of vibration path is larger than the path threshold, the disc is an abnormal disc. | 05-28-2009 |
20090135865 | Method for controlling power of an optical disk drive - A method for controlling laser power of an optical disk drive is provided. Firstly, a power-controlling curve of a first loop circuit is formed according to a real test. Next, two test points are selected from the power-controlling curve. Then, the voltage outputted from a second loop circuit is adjusted. After that, whether the generated internal power signal is equal to the internal power signal of the two test points is checked. Afterwards, the voltage outputted from the second loop circuit is recorded. Then, the gain of the two loop circuits under the same change of the internal power signal is calculated. Lastly, a gained power-controlling curve of the first loop circuit is used as a power-controlling curve of the second loop circuit, such that the power-controlling curve is quickly obtained. | 05-28-2009 |
20090135867 | Temperature compensation method for laser power of an optical disk drive - A temperature compensation method for laser power in an optical disk drive is provided. A predetermined linear-fitting power curve and a temperature-changing slope curve are previously stored in the optical disk drive. Firstly, an output of laser power is controlled according to the predetermined linear-fitting power curve to read/write data. Next, the temperature of the disk drive is detected. Then, whether the temperature has changed is checked. If the temperature has not changed, the method continues to read/write data. If the temperature has changed, the method obtains a relative slope from the slope curve by use of the temperature of the disk drive, displaces the slope of the predetermined linear-fitting power curve with the obtained relative slope to form a new linear-fitting power curve for replacing the predetermined linear-fitting power curve, and controls the output of laser power. | 05-28-2009 |
20090285060 | METHOD OF ADJUSTING GAIN BALANCE OF OPTICAL TRANSDUCER - A method of adjusting gain balance of an optical transducer includes the following steps. First, two external gains are predetermined. Next, the projection position of a reflection spot is adjusted toward one side of the optical transducer, and the current output values of the optical transducer each corresponding to one of the external gains are measured, respectively, Next, the projection position of the reflection spot is adjusted toward the other side of the optical transducer, and the current output values of the optical transducer each corresponding to one of the external gains are measured, respectively. Then, a gain balance value of the optical transducer is adjusted, and is set as the external gain. Next, the projection position of the reflection spot is adjusted. Finally, the projection position of the reflection spot, where the current output value of the transducer is equal to 0, is locked to complete the adjustment rapidly. | 11-19-2009 |