Patent application number | Description | Published |
20090129510 | FREQUENCY SHIFT KEYING (FSK) DIGITAL SIGNAL RECEIVING APPARATUS - A frequency shift keying digital signal receiving apparatus includes a detecting portion detecting a new signal on the basis of a signal, from which a correlated ambient noise is filtered out by an adaptive filter, a holding portion holding a first electric power for the signal received before a new signal is detected, a calculating portion calculating a second electric power for the signal received after the new signal is detected, a comparing portion comparing levels of the first and second electric powers, a selector selecting the signal, from which the correlated ambient noise is filtered out, when the first electric power is higher than the second electric power and selecting the signal bypassing the adaptive filter when the first electric power is lower than the second electric power, and a demodulating portion demodulating a desired signal on the basis of the signal selected by the selecting portion. | 05-21-2009 |
20090129520 | DIGITAL SIGNAL RECEIVING APPARATUS - A digital signal receiving apparatus includes: detection-judging portion judging a possible presence of a desired signal when a signal level of a smoothed signal is greater than a reference level; wherein said first smoothed signal and said second smoothed signal are compared in order to generate a detection signal representing a judgment of a possible presence of a desired signal, said second smoothed signal having a convergence speed slower than that of the first smoothing filter, a filter controlling portion switching an adaptive filter from an adaptive mode to a non-adaptive mode when the detection-judging portion judges the possible presence of the desired signal and switching from the non-adaptive mode to the adaptive mode when the detection-judging portion judges the absence of the desired signal; a limiting portion limiting a signal level of an auto-correlation signal to the signal level of the smoothed signal; and a demodulating portion demodulating the auto-correlation signal having the signal level limited by the limiting means so as to generate a demodulated signal, wherein the input to the demodulator is limited to the level of a smoothed signal, said smoothed signal being generated from the input of the detection judging portion. | 05-21-2009 |
20090129523 | DIGITAL SIGNAL RECEIVING APPARATUS - A digital signal receiving apparatus includes a detection-judging portion having a first smoothing filter generating a first smoothed signal by smoothing an auto-correlation signal and judging a possible presence of a desired signal when a signal level of the first smoothed signal is greater than a reference level and an absence of the desired signal when being smaller than the reference level. The smoothing filter includes a limiting portion limiting a fluctuation width of the first smoothed signal; and an adjusting portion configured to adjust the fluctuation width of the first smoothed signal limited by the limiting portion to be reduced while an elapsing time after the detection-judging means judges the possible presence of the desired signal is increasing. | 05-21-2009 |
Patent application number | Description | Published |
20130329121 | VARIABLE MAGNIFICATION OPTICAL SYSTEM AND IMAGING APPARATUS - A variable magnification optical system consists of a negative first lens group, a stop that is fixed relative to an image plane during magnification change, and a positive second lens group, which are in this order from an object side. A distance between the first lens group and the second lens group in an optical axis direction becomes shorter when magnification is changed from a wide-angle end to a telephoto end. The first lens group consists of a positive lens having a convex object-side surface and two negative lenses, in this order from the object side. The variable magnification optical system satisfies the following formula (1) about Abbe number νd1 of the positive lens in the first lens group for d-line: | 12-12-2013 |
20130335831 | VARIABLE MAGNIFICATION OPTICAL SYSTEM AND IMAGING APPARATUS - A variable magnification optical system includes a positive first lens group, a negative second lens group, a stop, a positive third lens group and a positive fourth lens group, which are in this order from an object side. The first lens group, the stop and the third lens group are fixed, but the second lens group and the fourth lens group move in an optical axis direction during magnification change. The fourth lens group has a focusing function. The third lens group includes at least an aspherical surface, and consists of, in the following order from the object side, a positive lens and a cemented lens of a positive lens and a double-concave lens cemented together. The variable magnification optical system satisfies a predetermined formula. | 12-19-2013 |
20140347749 | IMAGING LENS AND IMAGING APPARATUS - The imaging lens substantially consists of a first lens group, an aperture stop, a positive second lens group which is a focusing group, and a third lens group in this order from the object side. The first lens group substantially consists of a positive first sub lens group composed of a negative meniscus lens, a positive meniscus lens, and a positive lens; and a second sub lens group including a negative lens and a cemented lens, in this order from the object side. The second lens group substantially consists of a positive single lens or a cemented lens. The third lens group substantially consists of a cemented lens, a positive lens, and a negative lens in this order from the object side. | 11-27-2014 |
20140362455 | IMAGING LENS AND IMAGING APPARATUS INCLUDING THE SAME - The imaging lens substantially consists of a front group having positive refractive power, an aperture stop, a rear group having positive refractive power in this order from the object side. The front group substantially consists of a lens having a negative meniscus shape with a convex surface toward the object side, a negative lens, and a positive lens in this order from the object side. The rear group substantially consists of a positive lens, a negative lens, a positive lens, and a positive lens in this order from the object side. In the case that the Abbe numbers with respect to the d-line of the first lens and the second lens from the object side in the front group are respectively ν1 and ν2, conditional expressions (1) and (2) below are satisfied: | 12-11-2014 |