Abstract: A method and device for adequately controlling the DC bias of each of the optical modulating sections of an optical modulator even while the optical modulator is operating in normal mode and even with a simple structure.

Abstract: The present invention provides a broadcast receiving terminal which improves power conservation, in which a user does not miss broadcast contents s/he likes. The broadcast receiving terminal (100) includes: a display unit (120) for displaying TV program content; a state administration unit (112) which judges whether or not to display the TV program content, based on the user's operation; and a first processing unit (110), which receives a digital broadcast wave and operates as follows: executes decoding on stream information, and causes the TV program content to be displayed in the display unit (120) when the TV program content are judged to be displayed. The first processing unit (110) presents an outline indicating real-time TV program information so that the outline is synchronized with the TV program content when the TV program content are judged not to be displayed.

Abstract: The present invention provides a cost-saving and space-saving optical modulator enabling application of modulation signals with high phase difference accuracy without using a separate component for generating a phase difference outside of the optical modulator, when identical modulation signals having a predetermined phase difference are applied into a plurality of modulation electrodes.

Abstract: A terminal determines a target value of stream data to be stored in its buffer in relation to its buffer capacity and the transmission capacity of the network. Also, the terminal arbitrarily determines a delay time from when the terminal writes a head data of the stream data to the buffer to when the terminal reads the data to start playback in a range not exceeding a value obtained by dividing the buffer capacity by the transmission capacity. The target value and the delay time are then both notified to a server. Based on those notified values, the server controls the transmission speed so that the buffer occupancy of the terminal changes in the vicinity of the target value without exceeding the target value.

Abstract: A method and device for stabilizing operation point and optical output of an external optical modulator. A low-frequency signal below a lower limit of signal frequency band of an input signal inputted to optical modulator is superimposed onto direct current bias. A low-frequency component included in detector output is extracted. On the basis of the low-frequency signal, output of the low-frequency component is normalized, and output-light of light source is controlled in accordance with normalized low-frequency component. Means of controlling optical output of light source, in control of output-light of light source, detects the output-light, compares the value of detected output-light to a standard value of primary optical output, and adjusts the output-light. The standard value is modified according to a ratio of primary value of normalized low-frequency component to a subsequent value, and means controlling optical output of light source is operated on the basis of modified standard value.

Abstract: Present invention offers an optical modulator capable of efficiently transmitting electric signals to an acting portion of a signal electrode with acting on an optical waveguide even when the electric signals are in high frequency zone, and capable of performing high frequency broad band operation. The optic modulator comprises a substrate 1 formed of a material having electro-optical effect, an optical waveguide formed on the substrate, and an electrode 3 for modulating the light passing through the optical waveguide. The optical modulator is characterized in that an electric signal connection pad unit 6 is provided on a part of the electrode, and in that the thickness of the substrate which is located at least on a lower part of the electric signal connection pad unit 6 and directly or indirectly continuous to the electric signal connection pad unit 6 is thinner than the thickness of other parts of the substrate.

Abstract: The purpose of present invention is to provide the method and device for stabilizing the operation point and optical output of external optical modulator, which can control the wave pattern deformation of electrical signal array and set up stably the operation point of modulation curve of optical modulator and the optical output from optical modulator, even in case there is an optical output variation of the light source itself or a transmission factor variation in optical modulator.

Abstract: A content transmission system capable of realizing UI operations which are adapted to each specific content which is transmitted to a terminal device is provided. In the content transmission system, a content described in hypertext is transmitted from a content server 1 to a terminal device 3 via the network so as to be displayed at the terminal device 3. The content contains program identification information. In the content server 1, a server controlling section 11 transmits the content stored in the content storage section 12 to the terminal device 3, and transmits a UI operation program stored in a program storage section 13. In the terminal device 3, a display processing section 35 displays the content which has been transmitted from the content server 1. A UI operation execution section 34 executes the operations described in the UI operation program which has been transmitted from the content server 1.

Abstract: A terminal determines a target value S_target of stream data to be stored in its buffer in relation to its buffer capacity and the transmission capacity of the network. Also, the terminal arbitrarily determines a delay time T_delay from when the terminal writes a head data of the stream data to the buffer to when the terminal reads the data to start playback in a range not exceeding a value obtained by dividing the buffer capacity by the transmission capacity. Those target value and the delay time are then both notified to a server. Based on those notified values, the server controls the transmission speed so that the buffer occupancy Sum of the terminal changes in the vicinity of the target value without exceeding the target value.