Abstract: A D/A conversion apparatus includes a high-frequency amplifying and interpolating circuit for amplifying and interpolating only a high-frequency component of an input digital signal so as to produce an amplified and interpolated component together with the other components except the high-frequency component; a D/A converting circuit for converting an output digital signal of the high-frequency amplifying and interpolating circuit into an analog signal; and a suppressing circuit for suppressing a high-frequency component of the analog signal. Accordingly, the apparatus produces an audio signal waveform in which quantizing noise is reduced and high-frequency sound characteristics are improved.

Abstract: A method for recording and reproducing information, including plural channel audio signals on and from a recording medium. A sampling operation at a predetermined sampling frequency is respectively performed against plural channel audio signals, a modulation operation of a predetermined modulation system is performed respectively for each of a plurality of channels of the sampled data, an identification code identifying each channel is added to each of plural channel coded information signals, and subsequently the coded information signals are multiplexed by a time division multiplexing operation and recorded on the recording medium, together with one channel analog audio signal or by themselves.

Abstract: Method of recording and reproducing picture information and a recording medium on which the picture information is recorded by the method, and an apparatus for playing such a recording medium. In addition to a coded information signal, graphic codes including picture information occupying N (N being a natural number equal to or greater than 2) channels and inserted as the subcode of the coded information signal are recorded on the recording medium. One of the graphic codes which occupies one of the N channels consists of at least a code train group obtained by arranging consecutively a plurality of code trains which relate to a series of information obtained by said coded information signal and include picture information of the same picture. At the time of playing of the recording medium, only one of the graphic codes occupying the one of said N channels is stored in a memory in response to a command and a picture signal corresponding to contents stored in the memory is generated.

Abstract: A recording medium playing apparatus having a sound field control function. A memory stores sound field data representing specified sound field patterns in conjunction with recording medium ID data. Upon playback, appropriate sound field data is retrieved based on the ID data and is used to correct audio signals with the corresponding sound field. Every time a new recording medium is set, the relevant sound field is automatically established.

Abstract: A disc playing apparatus allows to set the reproduction speed of subcode information at a designated speed. The subcode read-out by a reading device is decoded by a decoding device and each piece of digital data successively output from the decoding device is transmitted at a predetermined transmission rate. The interval between pieces of the digital data is varied in response to a designated reproduction speed, and at the same time each piece of the digital data is transmitted at the predetermined transmission rate.

Abstract: A recording media playing apparatus including tonal response control circuit configured to control the tone of reproduced sounds, by controlling signal levels of frequency components in a plurality of frequency bands, which are set to divide the frequency range of audio signals read out from the recording media, to designated variation ratios.

Abstract: Method and apparatus of recording and reproducing picture information on a recording medium. In addition to video format signal and a coded information signal, graphic codes including picture information are recorded on the recording medium, by inserting the graphic codes as a subcode of the coded information signal. At the time of reproduction, a signal according to the graphic codes is mixed with the video format signal. When the recording medium is played back, a portion of the video format signal corresponding to a predetermined period of the video format signal read-out from the recording medium is written in a memory, and the signal according to the graphic code is mixed with a still picture video format signal which is produced by repeatedly reading the stored content of the memory.

Abstract: Method and apparatus of recording and reproducing picture information on a recording medium. In addition to a coded information signal, subcodes together with an identification code for identifying the coding system of the subcodes are recorded in a first recording area of a recording medium. The subcodes are preferably graphic codes including picture information and character codes having predetermined bit patterns, and are decoded in accordance with the identification code at the time of the playback of the recording medium.

Abstract: Method of recording and reproducing picture information and a recording medium on which the picture information is recorded by the method, and an apparatus for playing such a recording medium. In addition to video format signal and a coded information signal, graphic codes including picture information are recorded on the recording medium correspondingly to playback sections of the video format signal, the graphic codes being inserted as the subcode of the coded information signal. At the time of playback of the recording medium, a video signal according to the graphic codes corresponding to the playback section of the video format signal is generated each time one playback section of the video format signal is played back. Preferably, presence or absence of the graphic codes is displayed each time one playback section of the video format signal is played back.

Abstract: An apparatus for reproducing and processing picture information for forming a picture signal corresponding to a graphic code obtained from a recording medium on which, in addition to a video format signal and a coded information signal, graphic codes including picture information are recorded, the graphic codes being inserted as a subcode of the coded information signal, and for mixing the picture signal in the video format signal obtained from the recording medium.The apparatus is provided with a display mode changing device for changing a mode of display of the picture signal in response to the display mode changing command. According to another feature, a plurality of memories for storing a plurality of graphic codes are provided, and a graphic code of a designated channel is read-out when the designation of channel is changed.

Abstract: An input data processor of the present invention has a dither signal adder for adding a dither signal to digital data which corresponds to an alternating signal of the type which crosses the zero level each time the alternating signal varies from a maximum to a minimum (i.e., positive max to negative max). The resultant signal of the digital signal added to the dither signal is sent to a level shift circuit which shifts the digital data output from the adder to a positive or negative level, which has sufficient magnitude to prevent the signal from crossing the zero level during variation from max to min. By eliminating zero crossing with this shifting operation, the present invention prevents inversion of the MSB of the digital signal, which also prevents glitches in the analog output. These glitches were previously caused by inversion of the MSB.

Abstract: Playback method for use in an apparatus for playing a recording medium having a lead-in area, a first area in which only a coded information signal is recorded, and a second area in which a video format signal and a coded information signal are recorded by using a multiplexing operation. The method is characterized by the operations of reading information recorded in the lead-in area in response to a command, moving an information reading point of the pickup to the first area of the recording medium when subcode picture presence information, which indicates that a graphic code including picture information is inserted in a subcode of the coded information signal, is detected from information recovered from the lead-in area, and reproducing information of the first area preferentially to other areas of the recording medium.

Abstract: An apparatus for playing a disc on which, in addition to a coded information signal, a digital information signal divided into blocks is recorded as a subcode together with a block identification signal for identifying the blocks, comprises a reading device for reading the coded information signal and the subcode from the disc, a decoder for decoding the subcode to produce an information signal, a repeater for repeating the subcode read out by the reading device to the decoder in response to a repeat command, and a controller for controlling the reading device and the repeater.

Abstract: Method of recording and reproducing picture information and a recording medium on which the picture information is recorded by the method, and an apparatus for playing such a recording medium. In addition to a coded information signal, graphic codes including picture information and audio codes made up of codes by which data can be compressed at a compression rate higher than that of the coded information signal. The graphic codes and said audio codes are inserted as the subcode of the coded information signal together with identification codes indicating whether the codes include the picture information or the audio information. At the time of playback of the recording medium, the subcode is demodulated in accordance with the identification codes.

Abstract: At least one group of division screen data is inserted and recorded, together with music data groups, on a disc in each of a plurality of groups of music data which are divided by Q channel data in a subcode in a CD format, and one group of music data group is successively selected and read from the disc. The division screen data group contained in the read music data group is written into the corresponding division screen storage regions, and the written data are read from a total storage region composed of all the division screen storage regions in a prescribed reading sequence, thus providing an image signal representing a total screen composed of division screens indicated by the divided screen data group. Accordingly, a displayed image can be formed or varied to indicate the progress or sequence of audio information as it is progressively reproduced or played back.

Abstract: An apparatus for reproducing and processing picture information for forming a picture signal corresponding to a subcode obtained from a recording medium on which, in addition to a coded information signal, graphic codes including picture information occuyping N (N being a natural number equal to or greater than 2) channels and a recording medium code for specifying the recording medium are recorded, the graphic codes and the recording medium code being inserted as the subcode of the coded information signal.

Abstract: A disk player for a disk having video signals and digital audio signals recorded thereon. The disk player includes a video reproducing system for reproducing video signals recorded on the disk, an audio reproducing system for reproducing digital audio signals recorded on the disk as analog audio signals, and a processing circuit for converting the digital audio signals into a video signal so that the audio signals recorded on the disk can be displayed.

Abstract: Method of recording and reproducing picture information and a recording medium on which the picture information is recorded by the method, and an apparatus for playing such a recording medium. In addition to a coded information signal, graphic codes including picture information being inserted as a subcode of the coded information signal and identification information indicating areas of the recording medium in which predetermined sections of the subcode are recorded are recorded on the recording medium. At the time of playback of the recording medium, the areas are searched in response to a command by using the identification information and a picture signal corresponding to the graphic codes obtained by reading information recorded in that areas of the recording medium.

Abstract: A dither circuit including an adder for receiving an input signal and a dither signal which is generated by a dither signal generator, a level detection circuit for detecting the signal level of the input signal, and a dither control circuit for stopping the feeding of the dither signal to the adder when the level detection circuit detects that the signal level of the input signal is zero.

Abstract: A signal processing circuit in a playback system, according to the present invention, comprises a storage device for temporarily storing a digital signal output from a digital output stage of the playback system and a controller for controlling the data stored in the storage device in such a manner that the data is sent out from the storage means with a time difference.