Abstract: A display device includes a liquid crystal display panel that varies a phase of polarized light via liquid crystal molecules, and having first and second polarizing plates respectively disposed on opposite sides of the liquid crystal display panel; a first light guide plate including a surface having a plurality of recessed patterns, to reflect light input through a side surface of the first light guide plate, and to output two-dimensional light towards the liquid crystal display panel; and a second light guide plate including a surface having a plurality of recessed patterns, the plurality of recessed patterns of the second guide plate facing the plurality of recessed patterns of the first light guide plate.

Abstract: Disclosed is a transparent display device including a light guide plate formed with a plurality of concave patterns at the lower surface thereof to totally reflect polarized light entered in a lateral direction while transmitting natural light entered from a lower direction therethrough; a light source disposed in a lateral direction of the light guide plate to emit visible light including first and second polarized lights; a first polarizing plate disposed at a lateral portion of the light guide plate to transmit either one of the first and second polarized lights through the light guide plate; a liquid crystal panel for driving liquid crystals to change the phase of the polarized light; and a second polarizing plate for controlling an amount of the polarized light according to the changed phase of the polarized light.

Abstract: Disclosed is a method for evaluating a moving image resolution capable of quantitatively evaluating a moving image resolution for a display device. The method comprises displaying a test pattern on a screen, and moving the test pattern in a predetermined direction; obtaining an image of the test pattern on the screen; removing noise from the image; detecting edge regions of the image having noise removed therefrom; emphasizing the detected edge regions; scanning the emphasized edge regions by rotating any reference line a plurality of times, the reference line passing through a center point of the emphasized edge regions; and analyzing a pattern of the scanned result, and comparing it with the original test pattern.

Abstract: A fiber to the home (FTTH) system based on a passive optical network (PON) includes an optical line terminal (OLT) block, an optical network terminal (ONT) block, and an optical distribution network (ODN). The ONT block includes a video-optical line terminal (V-OLT) and an OLT to output optical signals of the V-OLT and the OLT by multiplexing the optical signals. The V-OLT receives cable TV (CATV), master antenna (MATV), and satellite broadcasting (SB) optical signals inputted from a broadcasting service network to output received signals as a first optical signal having a predetermined wavelength band. The ONT block includes a video-optical network terminal (V-ONT) and an (ONT) to split multiplexed data communications signals, and CATV broadcasting, MATV broadcasting, and (SB) optical signals. The V-ONT processes the split CATV broadcasting, MATV, and (SB) optical signals to provide subscribers with the split cable CATV, MATV and SB optical signals.

Abstract: A broadband light source includes an optical amplifier having amplifying mediums connected in series outputs an amplified spontaneous emission light over a wide wavelength range forward or backward. A circulator connected in series to the optical amplifier returns back to the amplifier spontaneous emission light outputted backwardly from the amplifier. A first pumping means located between the circulator and the optical amplifier pumps a pumping light to the optical amplifier, and a second pumping means located after the optical amplifier pumps a pumping light to the optical amplifier.

Abstract: A solution for allowing conditional access to IP-based broadcast services in a passive optical network is disclosed. When a subscriber requests broadcast services by selecting a broadcast channel, an IP set-top converts the request into an IGMP join message and forwards the message to an ONU/ONT, a unit on the subscriber's side. The ONU/ONT delivers the message to an OLT interworking with a router while storing mapping information of the port that received the message and a MAC address of the selected channel. Thereafter, the OLT extracts information on MAC address of the IP set-top box and the requested broadcast data. The OLT compares the extracted information to the subscriber's subscription information and determines whether to provide the requested broadcast services. If the broadcast services may be provided, the broadcast data provided from the broadcast server is transmitted to the IP set-top box via ONU/ONT based on the stored mapping information.

Abstract: An automatic gain controller for controlling gain values of an optical fiber amplifier. The automatic gain controller includes a first opto-electric conversion unit for converting a portion of optical signals that are input into the optical fiber amplifier into electrical signals to output the converted electrical signals. A second opto-electric conversion unit converts a portion of output optical signals output from the optical fiber amplifier into electrical signals and then outputs the converted electrical signals. A transient suppressing unit generates pulse typed waveforms when a change in channel number is generated during monitoring outputs of the first opto-electric conversion unit, and a comparing unit compares the sum of output signals of the transient suppressing unit and output signals of the first opto-electric conversion unit with output signals of the second opto-electric conversion unit.

Abstract: A broadband light source includes an optical amplifier having amplifying mediums connected in series outputs an amplified spontaneous emission light over a wide wavelength range forward or backward. A circulator connected in series to the optical amplifier returns back to the amplifier spontaneous emission light outputted backwardly from the amplifier. A first pumping means located between the circulator and the optical amplifier pumps a pumping light to the optical amplifier, and a second pumping means located after the optical amplifier pumps a pumping light to the optical amplifier.

Abstract: A fiber to the home (FTTH) system based on a passive optical network (PON) includes an optical line terminal (OLT) block, an optical network terminal (ONT) block, and an optical distribution network (ODN). The ONT block includes a video-optical line terminal (V-OLT) and an optical line terminal (OLT) in order to output optical signals of the video-optical line terminal (V-OLT) and the optical line terminal (OLT) by multiplexing the optical signals. The VOLT receives cable TV, master antenna TV, and satellite broadcasting optical signals inputted from a broadcasting service network so as to output received signals as a first optical signal having a predetermined wavelength band. The OLT includes a first downstream data optical transmitter and a first upstream data optical receiver and outputs a data communication signal inputted from a data service network as a second optical signal having different wavelength from the video-optical line terminal.

Abstract: An automatic gain controller for controlling gain values of an optical fiber amplifier. The automatic gain controller includes a first opto-electric conversion unit for converting a portion of optical signals that are input into the optical fiber amplifier into electrical signals to output the converted electrical signals. A second opto-electric conversion unit converts a portion of output optical signals output from the optical fiber amplifier into electrical signals and then outputs the converted electrical signals. A transient suppressing unit generates pulse typed waveforms when a change in channel number is generated during monitoring outputs of the first opto-electric conversion unit, and a comparing unit compares the sum of output signals of the transient suppressing unit and output signals of the first opto-electric conversion unit with output signals of the second opto-electric conversion unit.