Abstract: A DMD (digital micromirror device) includes a substantially rectangular element face made up of plural mirror elements arranged in a matrix. The DMD is provided with a light shielding cover having a light transmitting portion which corresponds to the element face. Radiated from the illumination optical system including a rod integrator, the illumination light enters the element face, on a flat surface including the diagonal line of the element face, at an inclined angle with respect to the normal to the element face. Near a light exit face of the rod integrator, a mask plate is disposed to regulate a part of the illumination light. The mask plate has a mask aperture of substantially rhombus shape. The illumination light passing the mask aperture is reshaped so that an illumination area can be a substantially rectangular shape on the element face.

Abstract: Music piece data of so-called managed music pieces, each of which requires allowance of performance for each karaoke apparatus are stored in a hard disk in the same manner as music piece data of other karaoke music pieces. A ROM (20), which has stored therein key data for allowing performance of a managed music piece, is produced for each of the managed music pieces and for each of karaoke apparatuses. Performance of a managed music piece is allowed by setting a corresponding ROM (20) into a karaoke apparatus. Accordingly, a karaoke apparatus is not required to have a medium such as a CD-ROM for each of managed music pieces, and the copyright holder of a managed music piece can physically manage the number of allowed performances by way of the ROM (20).

Abstract: A projection type video reproducing apparatus includes a video display element that visualizes a video signal, a video display element drive circuit that drives the video display element, a high-speed response light source that applies projection light onto the video display element, a light source drive circuit that turns the light source on, and a video signal conversion portion.

Abstract: A DMD (digital micromirror device) includes a substantially rectangular element face made up of plural mirror elements arranged in a matrix. The DMD is provided with a light shielding cover having a light transmitting portion which corresponds to the element face. Radiated from the illumination optical system including a rod integrator, the illumination light enters the element face, on a flat surface including the diagonal line of the element face, at an inclined angle with respect to the normal to the element face. Near a light exit face of the rod integrator, a mask plate is disposed to regulate a part of the illumination light. The mask plate has a mask aperture of substantially rhombus shape. The illumination light passing the mask aperture is reshaped so that an illumination area can be a substantially rectangular shape on the element face.

Abstract: In an informing mode, a coin box outputs informing pulses, the number of which corresponds to the number of remaining credits, in response to pulses supplied from a service providing apparatus (steps S23 to S26). The service providing apparatus counts the number of informing pulses to detect the number of remaining credits. In an accounting mode, when the coin box detects a pulse output from the service providing apparatus, the coin box decrements the number of remaining credits one by one for every detection of a pulse output from the service providing apparatus (steps S27 to S29). In this way, the accounting is performed by decrementing the number of remaining credits in the coin box by the number of pulses corresponding to the service compensation.

Abstract: Even music piece data of so-called managed music pieces each of which requires allowance of performance for each karaoke apparatus are stored in a hard disk in the same manner as music piece data of other karaoke music pieces. A ROM (20), which has stored therein key data for allowing performance of a managed music piece, is produced for each or the managed music pieces and for each of karaoke apparatuses. Performance of a managed music piece is allowed by setting a corresponding ROM (20) into a karaoke apparatus. Accordingly, a karaoke apparatus is not required to have a medium such as a CD-ROM for each of managed music pieces, and the copyright holder of a managed music piece can physically manage the number of allowed performances by way of the ROM (20).

Abstract: In an informing mode, a coin box outputs informing pulses the number of which corresponds to the number of remaining credits, in response to pulses supplied from a service providing apparatus (steps S23 to S26). The service providing apparatus counts the number of informing pulses to detect the number of remaining credits. In an accounting mode, when the coin box detects a pulse output from the service providing apparatus, the coin box decrements the number of remaining credits one by one for every detection of a pulse output from the service providing apparatus (steps S27 to S29). In this way, the accounting is performed by decrementing the number of remaining credits in the coin box by the number of pulses corresponding to the service compensation.

Abstract: A digital communication system communicates data between a transmitter station and a receiver station by means of a carrier wave. The transmitter station has a packet assembler for assembling data having an original format into a packet, an encoder for encoding the data in the packet from an initial eight-bit form into a fourteen-bit form, and a modulator for modulating a carrier wave by the encoded data so as to transmit the packet of encoded data in the fourteen-bit form. The receiver station has a demodulator receptive of the modulated carrier wave for demodulating the same to separate therefrom the packet of encoded data, a decoder for decoding the encoded data in the packet from the fourteen-bit form into the initial eight-bit form, and a packet disassembler for disassembling the packet of decoded data to restore the original format of the data having the initial eight-bit form.

Abstract: A karaoke apparatus is provided with a first storage for storing a plurality of karaoke data files corresponding to a plurality of karaoke songs and containing an accompaniment data and a picture index data, a second storage for storing a plurality of primary pictures, and a third storage for storing a plurality of secondary pictures which are mixed to the primary pictures. Upon requesting a desired karaoke song to select the corresponding karaoke data file, particular ones of the primary pictures and the secondary pictures are retrieved from the second and third storages according to the picture index data contained in the selected karaoke data file. A video mixer operates for mixing the retrieved secondary picture to the retrieved primary picture to synthesize a composite picture which meets a mood of the requested karaoke song. A tone generator operates according to the accompaniment data contained in the selected karaoke data file to sound an instrumental accompaniment of the requested karaoke song.

Abstract: A karaoke network system includes a central station for serving karaoke data and image data, and a group of karaoke terminals connected to the central station through a communication line having a common channel and a plurality of parallel channels for locally presenting a karaoke accompaniment and a background picture. The central station includes a first server responsive to a request command from karaoke terminal for transmitting to the common channel requested karaoke data individually addressed to the karaoke terminal, and a second server operative independently of the first server for transmitting to the parallel channels a plurality of different image data continuously broadcast to each karaoke terminal.

Abstract: A digital signal processing device is disclosed. At an intermediate time point between respective sample data of a digital signal input is interpolated data expressed by the formula ##EQU1## wherein R.sub.l, m and n are positive integers. The digital signal interpolated with this interpolation data d is applied to a digital-to-analog converter where it is converted to an analog signal. This interpolation serves as a low-pass filter for removing unnecessary harmonic components, with the result that a analog filter used in a posterior stage after the digital-to-analog converter requires no steep characteristics and hence can be of a remarkedly simple structure and be manufactured at reduced cost.

Abstract: An FM stereophonic receiver is arranged so that a central processing unit assigned for selection of a broadcasting station is burdened, based on a clock pulse of the central processing unit, to generate sub-carriers synchronized with a pilot signal contained in a composite signal, for being used in multiplex demodulation, whereby to improve signal-to-noise ratio of the multiplex demodulated signals, and to simplify the circuit arrangement of the receiver.

Abstract: An FM stereo demodulation circuit comprises a resistor voltage dividing network having a plurality of outputs; a first switch circuit having a plurality of analog switches which respectively couple the outputs of the voltage dividing network to a first output terminal; a second switch circuit having a plurality of analog switches which respectively couple the outputs of the voltage dividing network to a second output terminal; and a switch control circuit which sequentially enables the analog switches of the first and second switch circuits over one cycle period of a subscarrier signal in response to a pilot signal in an FM stereo composite signal. The circuits produce a staircase-wave multiplying signal having a waveshape which depends on the setting of the resistance values of resistors of the voltage dividing network.

Abstract: A DC voltage having a magnitude proportional to the amplitude of a pilot signal in a composite signal which is employed in the commercial FM stereo broadcasting is generated and divided to plural voltage levels through a resistor voltage dividing network having a plurality of outputs. The output voltages of the voltage dividing circuit network are reciprocatingly multiplexed to a common terminal over a multiplexing cycle in response to the pilot signal. A sinusoidal-wavelike staircase waveform signal having a fundamental frequency the same as the frequency of pilot signal is taken out of the common terminal by appropriately setting values of resistors in the voltage dividing circuit network. The sinusoidal-wavelike staircase waveform signal is smoothed to generate a sinusoidal cancel signal which is then combined with the composite signal to cancel out the pilot signal in the composite signal.

Abstract: A display device for digitally displaying a numerical value of plural figures on a display unit includes a detector for detecting the variation rate of the numerical value to be displayed. The brightness of a display section for an arbitrary figure of the numerical value is controlled in accordance with the detector output. The display device may be used in a radio receiver for displaying the receiving frequency.

Abstract: A magnetic recording and reproducing system is disclosed in which a frequency-modulated input signal is recorded on a magnetic medium together with a further signal which is discriminative from the frequency-modulated signal. The recorded frequency-modulated signal and further signal are frequency-demodulated so that the former reverts to the input signal and the latter represents an FM noise signal which is generated due to the wow and flutter during the recording and/or reproducing process. The extracted noise signal is mixed with the reproduced input signal thereby canceling an FM noise component in this reproduced signal. The mentioned further signal may be an amplitude-modulated signal of or a carrier wave signal for the frequency-modulated input signal.

Abstract: A radio receiver comprises a phase locked loop and an automatic frequency control loop which are selectively coupled with a voltage-controlled local oscillator to control a local oscillator frequency. The phase locked loop and the automatic frequency control loop have a common loop filter which supplies the voltage-controlled oscillator with a control voltage. The loop filter is arranged so that its time constant may be switched from a small value to a great value in response to switching of the operation mode of the voltage-controlled oscillator from a phase locked loop control mode for the selection of broadcasting station to an automatic frequency control loop control mode for the maintenance of the local oscillator frequency after tuning of the radio receiver. The radio receiver can be arranged so that the local oscillator frequency may be maintained by the phase locked loop after the tuning of the receiver to a weak broadcast signal when muting control is rendered ineffective by a muting switch.

Abstract: A signal level display apparatus arranged so that an ac signal is superposed upon either an input signal or a reference voltage of a comparator to display the input signal with differences in degrees of brightness of illumination of light-emitting elements constituting a display unit when viewed externally, to thereby distinguish the level of the input signal which is closer to the level of the reference voltage from the level departing away therefrom. This apparatus also displays simultaneously on said display unit the level of two different input signals in distinguished degrees of illumination of the light-emitting elements.

Abstract: A radio receiver comprises a voltage-controlled oscillator acting as a local oscillator, a capacitor to supply a control voltage to the voltage-controlled oscillator, a phase locked loop incorporating the voltage-controlled oscillator and adapted for a preset selection of a broadcast station, a charge/discharge control circuit to charge or discharge the capacitor adapted for automatic or manual selection of a broadcast station, and an automatic frequency control circuit adapted for maintenance of a local oscillator frequency when the broadcast station is received. A control circuit is provided which couples the phase locked loop or charge/discharge control circuit to the capacitor in response to the selection of one of the station select modes and couples the automatic frequency control circuit to the capacitor in response to the reception of the broadcast station in a good receiving condition.

Abstract: In an FM detecting circuit of either the ratio detecting circuit type or the quadrature detecting circuit type arranged to have an LC resonance circuit and to detect the amount of deviation of an FM input signal relative to the resonance frequency by utilizing the resonance characteristic of the LC resonance circuit in the vicinity of the resonance frequency to thereby perform FM detection, a semiconductor element is connected to the LC resonance circuit to expand the rectilinear region of the resonance characteristic and to reduce detecting distortions.