Abstract: A pulsed light generating method for generating a pulsed light by cutting out a laser light outputted from a laser light source with an intensity modulation type electro optic modulator, wherein: the electro optic modulator is driven by use of a drive signal that changes a voltage applied to the electro optic modulator between a voltage lower than a reference voltage and a voltage higher than the reference voltage, the reference voltage being a voltage applied to the electro optic modulator at which a transmittance of the laser light transmitting through the electro optic modulator is local maximum.

Abstract: A pulsed light generating method for generating a pulsed light by cutting out a laser light outputted from a laser light source with an intensity modulation type electro optic modulator, wherein: the electro optic modulator is driven by use of a drive signal that changes a voltage applied to the electro optic modulator between a voltage lower than a reference voltage and a voltage higher than the reference voltage, the reference voltage being a voltage applied to the electro optic modulator at which a transmittance of the laser light transmitting through the electro optic modulator is local maximum.

Abstract: A laser device includes: an optical fiber amplifier that amplifies and emits a signal light; a control unit that controls pumping power for pumping the optical fiber amplifier; and a signal light detector that detects signal light being propagated to the optical fiber amplifier or an ASE photodetector that detects light that is emitted from the optical fiber amplifier and that has wavelength for which the gain is higher than for the signal light, wherein the control unit suppresses the pumping power for pumping the optical fiber amplifier, when the intensity of the signal light detected by the signal light detector becomes less than or equal to a predetermined signal reference value, or when the intensity of the spontaneously emitted light detected by the ASE photodetector becomes greater than or equal to a predetermined ASE reference value.

Abstract: A light source device including a seed light generation device, a light amplification unit which optically amplifies seed light generated by the seed light generation device, and a wavelength conversion unit which converts the wavelength of the light optically amplified by the light amplification unit. The seed light generation device includes a pulsed light generation unit which generates pulsed light having a single wavelength, a pulse modulation unit which selectively passes and extracts a part of the pulsed light, and a timing adjustment unit which relatively adjusts the extracting timing of the pulsed light by the pulse modulation unit during the generation period of the pulsed light by the pulse generation unit, according to an operation.

Abstract: A laser device includes: an optical fiber amplifier that amplifies and emits a signal light; a control unit that controls pumping power for pumping the optical fiber amplifier; and a signal light detector that detects signal light being propagated to the optical fiber amplifier or an ASE photodetector that detects light that is emitted from the optical fiber amplifier and that has wavelength for which the gain is higher than for the signal light, wherein the control unit suppresses the pumping power for pumping the optical fiber amplifier, when the intensity of the signal light detected by the signal light detector becomes less than or equal to a predetermined signal reference value, or when the intensity of the spontaneously emitted light detected by the ASE photodetector becomes greater than or equal to a predetermined ASE reference value.

Abstract: A light source device including a seed light generation device, a light amplification unit which optically amplifies seed light generated by the seed light generation device, and a wavelength conversion unit which converts the wavelength of the light optically amplified by the light amplification unit. The seed light generation device includes a pulsed light generation unit which generates pulsed light having a single wavelength, a pulse modulation unit which selectively passes and extracts a part of the pulsed light, and a timing adjustment unit which relatively adjusts the extracting timing of the pulsed light by the pulse modulation unit during the generation period of the pulsed light by the pulse generation unit, according to an operation.

Abstract: A ranging apparatus 1 comprises a laser light emitter 3 for emitting pulsed laser light, a reflected light receiver 4 for receiving reflected light, a distance computer 10 for finding the distance from the elapsed time until the reflected light is received, and a distance display 8 for displaying this distance. The distance computer 10 has a counter 11 for counting the frequency when the reflected light satisfies a specific condition, a table production component 12 for producing a frequency distribution table corresponding to distance by adding up the counts, a distance determiner 13 for determining as the distance to the object of measurement the point when the frequencies in the frequency distribution table exceed a threshold, and a distance selector 15 for selecting a specific distance when a plurality of distances are determined, and displaying this distance on the distance display 8.

Abstract: A ranging apparatus 1 comprises a laser light emitter 3 for emitting pulsed laser light, a reflected light receiver 4 for receiving reflected light, a distance computer 10 for finding the distance from the elapsed time until the reflected light is received, and a distance display 8 for displaying this distance. The distance computer 10 has a counter 11 for counting the frequency when the reflected light satisfies a specific condition, a table production component 12 for producing a frequency distribution table corresponding to distance by adding up the counts, a distance determiner 13 for determining as the distance to the object of measurement the point when the frequencies in the frequency distribution table exceed a threshold, and a distance selector 15 for selecting a specific distance when a plurality of distances are determined, and displaying this distance on the distance display 8.

Abstract: A ranging apparatus 1 comprises a laser light emitter 3 for emitting pulsed laser light, a reflected light receiver 4 for receiving reflected light, a distance computer 10 for finding the distance from the elapsed time until the reflected light is received, and a distance display 8 for displaying this distance. The distance computer 10 has a counter 11 for counting the frequency when the reflected light satisfies a specific condition, a table production component 12 for producing a frequency distribution table corresponding to distance by adding up the counts, a distance determiner 13 for determining as the distance to the object of measurement the point when the frequencies in the frequency distribution table exceed a threshold, and a distance selector 15 for selecting a specific distance when a plurality of distances are determined, and displaying this distance on the distance display 8.

Abstract: An information recording and playback device for use with disk-type medium formatted in a ZCAV format. Sector marks are written on the disk-type recording medium and differ in frequency according to the zone to which the sector belongs. Where frequencies in adjacent zones are close, sectors in adjacent zones can be written with different polarities or sizes. The information recording and playback device is provided with a number of sector mark detection circuits, which number the same or less than the number of zones formed on the recording surface of the disk. Each sector mark detection circuit is set to correspond to one zone, and output a signal when the pattern of the sector marks of the zone to which that sector mark detection circuit corresponds can be detected. When the sector mark is detected by one of these sector mark detection circuits, the actual position of the head is determined.

Abstract: An optical disk replay device for replaying information from an optical disk recorded in a modified constant angular velocity (MCAV) format. The optical disk replay device has an optical head to output a reproduced signal based on the information stored in the optical disk. The signal from the optical head is passed through a series of delay circuits which output delayed signals based on the reproduced signal. Thereafter, a calculating circuit sums, or subtracts, the delayed signals and outputs an intermediate reproduced signal to a band limiting circuit which attenuates the frequency of the intermediate reproduced signal. A control circuit changes the amount of delay imparted by the delay circuits and to adjust the frequency range of the band limiting circuit.

Abstract: A karaoke system includes a plurality of terminal systems respectively reproducing music and video images of music pieces, and a center system connected to the plurality of terminal systems. The center system includes a musical performance information storage unit for storing digital performance information relating to music pieces to be reproduced and video image control information relating to video images to be reproduced simultaneously with the music, a plurality of music information generators for generating music information of the music piece on the basis of the digital performance information, video image storage unit for storing a plurality of video images, video image generator for generating a video image from the video image storage unit in accordance with the video image control information, and information transmitter for transmitting the digital performance information and the reproduced video image to the plurality of terminal systems.

Abstract: A laser power monitor circuit for monitoring the power of a laser used in a magneto-optical disk device and other related devices. In order to provide marks in the recording medium, a write power of the laser is required, and in between the marks, the laser is to have a pedestal power. During recording on the magneto-optical disk, recording corrections are performed at the start of the pedestal power and write power of the laser to provide marks in the recording medium which are properly shaped. The laser power monitor circuit accurately monitors the power of the laser light on a recording medium and includes a reverse correction circuit to provide reverse correction of the recording corrected values among the monitored values of laser power to bring the laser to the appropriate write power or pedestal power.

Abstract: A binary threshold value setting circuit comprises: a first detecting section to detect the positive polarity side of an input signal, a second detecting section to detect the negative polarity side of the signal; a first envelope detecting section to perform an envelope detection to the signal detected by the first detecting section, a second envelope detecting section to perform an envelope detection to the signal detected by the second detecting section, a threshold value setting section to generate a signal at a level between the level of the signal which has been envelope detected by the first envelope detecting section and the level of the signal which has been envelope detected by the second envelope detecting section, and a capacitor connected between the output side of the first detecting section and the output side of the second detecting section.

Abstract: There are disclosed an apparatus adapted to generate musical information of a synthetic sound in accordance with the MIDI (Musical Instrument Digital Interface) standard to carry out PCM (Pulse Code Modulation) recording of a natural effect sound including natural sound and/or a human voice such as back chorus to mix them to generate musical accompaniment, thus to mix a voice of singing sung with the musical accompaniment, and a recording medium used for such an apparatus.

Abstract: A laser drive circuit for modulating a laser beam intensity emitted from a laser device to a maximum power and a minimum power in accordance with a first and second values of a binary signal comprises: a photo-detector for detecting the laser beam emitted from the laser device to produce a detection output signal; a first differential amplifier for producing a maximum error detection signal representing a difference between the detection output signal applied thereto and a maximum reference; a second differential amplifier for producing a minimum error detection signal representing a difference between the detection output signal applied thereto and a minimum reference, a first sample and hold circuit for sampling and holding the maximum error detection signal at a timing of the first value of the binary signal and outputting the same as a maximum error signal; a second sample and hold circuit for sampling and holding the minimum error detection signal at a timing of the second value of the binary signal and

Abstract: In an image reproducing apparatus, a music information reproducing unit reproduces musical information, lyrics information or still picture information from a music information recording medium on which the musical information, the lyrics information or the still picture information relating to a plurality of music pieces are recorded, and an image information reproducing unit retrieves moving picture information in a predetermined order in correspondence with respective music pieces in the music information recording medium from an image information recording medium on which moving picture information divided into a plurality of moving picture information segments is recorded, and reproducing said picture information segments.

Abstract: A musical accompaniment playing apparatus comprises a MIDI sound source, a phoneme information memory, a playing information memory, a control means, a mixing means and a sound output means.When a user sings a song with a musical accompaniment and a back chorus, the control means controls the MIDI sound source to output an audio signal in accordance with a phoneme information stored in the phoneme memory and a playing information stored in the playing information memory. The output audio signal is mixed with a singing voice of the user at the mixing means and output from the sound output means as a song in harmony with the back chorus.

Abstract: A user management system is provided for a musical accompaniment playing (KARAOKE) apparatus. The system comprises an individual information recording medium, an input unit, a music information reproducing unit, a control unit and a calculation unit. The input unit is used to input user identification information and music piece selection. The control unit serves to set a musical environment and to record changes in the environment for the user. The calculation unit makes adjustments based on the number of music pieces recorded on the individual information recording medium.

Abstract: In a musical accompaniment playing apparatus, a reproducing unit reproduces control information from a recording medium on which control information is recorded according to a MIDI standard, a sound source unit generates musical accompaniment information by the control information, a transducer transforms a singer's voice to voice information, a control unit controls a volume level of the musical accompaniment information according to the singer's ability, mixing unit mixes the musical accompaniment information with the voice information, and an output unit outputs the mixed information as sound.