Abstract: A circuit for detecting a predetermined symbol of a digital data stream includes a frequency shifter, a correlator, a filter and a decision unit. The frequency shifter performs inverse-frequency shifting upon a first data to generate a first frequency-shifted data. The correlator calculates correlation upon the first frequency-shifted data and a second data to generate a correlated data. The filter, coupled to the correlator, filters and the correlated data to generate a filtered correlated data according to a time-domain windowing length. The decision unit, coupled to the filter, determines the predetermined symbol from the digital data stream according to the filtered correlated data.

Abstract: A color light guide panel, suitable for differentiating an incident light into multiple color lights is provided. The color light guide panel includes a substrate and a color light output structure. The substrate has multiple pixel regions, and the color light output structure is disposed in each of the pixel regions. The color light output structure includes a first nano-pattern, a second nano-pattern and a third nano-pattern. The incident light is scattered by the first nano-pattern for producing a first color light, scattered by the second nano-pattern for producing a second color light, and scattered by the third nano-pattern for producing a third color light. The color light guide panel can output uniform and high luminous first, second and third color light. Moreover, a liquid crystal display device having the above color light output structure is also provided.

Abstract: The invention provides a method for adjusting a speed-detection device for an object lens in an optical pickup head. The invention provides an adjusted optical disc drive, wherein the optical pickup head is accelerated/decelerated and the speed-detection device outputs a standard signal level. Next, the optical pickup head of an unadjusted optical disc drive is accelerated/decelerated under the same condition, and the speed-detection device outputs a speed signal level. Finally, the gain of a programmable gain amplifier is adjusted until the speed signal is equal to the standard signal.

Abstract: The invention provides a method for adjusting a speed-detection device for an object lens in an optical pickup head. The invention provides an adjusted optical disc drive, wherein the optical pickup head is accelerated/decelerated and the speed-detection device outputs a standard signal level. Next, the optical pickup head of an unadjusted optical disc drive is accelerated/decelerated under the same condition, and the speed-detection device outputs a speed signal level. Finally, the gain of a programmable gain amplifier is adjusted until the speed signal is equal to the standard signal.