Abstract: When a second communication unit receives an identifier received last in time by a second terminal apparatus from the second terminal apparatus as a last identifier, a relay recording control unit causes the second communication unit to transmit a list of identifiers recorded in a recording unit after the last identifier to the second terminal apparatus, and that, when the second communication unit receives the identifier included in the list from the second terminal apparatus as a transmission request identifier, extracts a first sound signal corresponding to the transmission request identifier from the recording unit and causes the recording unit to transmit the first sound signal extracted to the second terminal apparatus as the second sound signal.

Abstract: The semiconductor laser apparatus includes a semiconductor laser, a detection element for detecting the intensity of the output light from the semiconductor laser, an error detection circuit containing a gain controllable operation amplifying circuit and a gain-fixed type control amplifying circuit connected to a next stage to the gain controllable operation amplifying circuit, to which a semiconductor laser drive control signal is input and an output signal of the detection element is input as a negative feedback signal, for outputting an error signal corresponding to a difference between the two input signals, a high-frequency signal generating circuit for generating a high-frequency signal having a predetermined frequency, a high-frequency signal superimposing circuit for superimposing the high-frequency signal onto the output signal from the error detection circuit, and a laser drive circuit for supplying a drive current to the semiconductor laser on the basis of the output signal from the high-frequency

Abstract: The semiconductor laser apparatus includes a semiconductor laser, a detection element for detecting the intensity of the output light from the semiconductor laser, an error detection circuit containing a gain controllable operation amplifying circuit and a gain-fixed type control amplifying circuit connected to a next stage to the gain controllable operation amplifying circuit, to which a semiconductor laser drive control signal is input and an output signal of the detection element is input as a negative feedback signal, for outputting an error signal corresponding to a difference between the two input signals, a high-frequency signal generating circuit for generating a high-frequency signal having a predetermined frequency, a high-frequency signal superimposing circuit for superimposing the high-frequency signal onto the output signal from the error detection circuit, and a laser drive circuit for supplying a drive current to the semiconductor laser on the basis of the output signal from the high-frequency

Abstract: The semiconductor laser apparatus includes a semiconductor laser, a detection element for detecting the intensity of the output light from the semiconductor laser, an error detection circuit containing a gain controllable operation amplifying circuit and a gain-fixed type control amplifying circuit connected to a next stage to the gain controllable operation amplifying circuit, to which a semiconductor laser drive control signal is input and an output signal of the detection element is input as a negative feedback signal, for outputting an error signal corresponding to a difference between the two input signals, a high-frequency signal generating circuit for generating a high-frequency signal having a predetermined frequency, a high-frequency signal superimposing circuit for superimposing the high-frequency signal onto the output signal from the error detection circuit, and a laser drive circuit for supplying a drive current to the semiconductor laser on the basis of the output signal from the high-frequency