Abstract: During a normal operation, a tracking control signal from a tracking controller is supplied to an adder via a first switch and to a radial deviation component detector. The radial deviation component detector determines a radial deviation component EC of AC caused by radial deviation of an optical disk from the tracking control signal and supplied that component to the adder via another switch. For a track jump, the first switch is turned OFF, cutting off the tracking control signal. Thus, the radial deviation component EC and a jump pulse signal from a jump signal generator are added together by the adder. However, an offset of the tracking control signal TC detected by a DC component detector is further added. To avoid instability, the track jump is compensated so as to be normally carried out even if a DC offset is added to a tracking control signal.

Abstract: For changing services to readers who desires to obtain electronic books exactly or minutely, an electronic book management system 1 distributes at least electronic purchase certificates relating to books which are stocked at a bookstores owing a bookstore terminal device 2, in advance, to that bookstore terminal device 2. When buying the book(s), a reader obtains in an IC card 4 owned by her/him a purchase certificate(s) of that book(s) which she/he bought, from the bookstore terminal 2. When ordering to obtain the electronic book(s), the reader transmits the purchase certificate(s) from a reader terminal device 3 to the electronic book management system 1 through a communication network 5. The electronic book management system 1 changes over it's service when supplying the electronic book(s) to that reader depending upon the existence of the purchase certificate(s).

Abstract: A focus jump technique enables focus control on recording layers of a disc in such a manner that its effect is not absorbed by disturbance or a variation in the movement speed of an objective lens. The technique involves monitoring level of a focus error signal and rejecting noise from the error signal. A speed sensor detects movement speed of an objective lens; and a speed control circuit generates a voltage for controlling the objective lens, based on the detected movement speed. Movement speed of the objective lens is detected during focus jump, a corresponding lens drive signal is generated, and an end position is determined from behavior of the error signal immediately before the end of the jump. A focus control is pulled, from a focus point corresponding to one recording layer, into a focus point corresponding to another recording layer forcibly in a stable manner.

Abstract: A focus jump technique enables focus control on recording layers of a disc in such a manner that its effect is not absorbed by disturbance or a variation in the movement speed of an objective lens. The technique involves monitoring level of a focus error signal and rejecting noise from the error signal. A speed sensor detects movement speed of an objective lens; and a speed control circuit generates a voltage for controlling the objective lens, based on the detected movement speed. Movement speed of the objective lens is detected during focus jump, a corresponding lens drive signal is generated, and an end position is determined from behavior of the error signal immediately before the end of the jump. A focus control is pulled, from a focus point corresponding to one recording layer, into a focus point corresponding to another recording layer forcibly in a stable manner.

Abstract: A focus jump technique enables focus control on recording layers of a disc in such a manner that its effect is not absorbed by disturbance or a variation in the movement speed of an objective lens. The technique involves monitoring level of a focus error signal and rejecting noise from the error signal. A speed sensor detects movement speed of an objective lens; and a speed control circuit generates a voltage for controlling the objective lens, based on the detected movement speed. Movement speed of the objective lens is detected during focus jump, a corresponding lens drive signal is generated, and an end position is determined from behavior of the error signal immediately before the end of the jump. A focus control is pulled, from a focus point corresponding to one recording layer, into a focus point corresponding to another recording layer forcibly in a stable manner.

Abstract: A focus jump technique enables focus control on recording layers of a disc in such a manner that its effect is not absorbed by disturbance or a variation in the movement speed of an objective lens. The technique involves monitoring level of a focus error signal and rejecting noise from the error signal. A speed sensor detects movement speed of an objective lens; and a speed control circuit generates a voltage for controlling the objective lens, based on the detected movement speed. Movement speed of the objective lens is detected during focus jump, a corresponding lens drive signal is generated, and an end position is determined from behavior of the error signal immediately before the end of the jump. A focus control is pulled, from a focus point corresponding to one recording layer, into a focus point corresponding to another recording layer forcibly in a stable manner.

Abstract: A track jump is set so as to be normally carried out even if a DC offset is added to a tracking control signal.

Abstract: In a control apparatus for operating with program data, it is possible to alter the operation of a control circuit by rewriting the data of the program memory built in an LSI, with ease and at a low cost independently of the operation of the control circuit.

Abstract: In a control apparatus for operating with program data, it is possible to alter the operation of a control circuit by rewriting the data of the program memory built in an LSI, with ease and at a low cost independently of the operation of the control circuit. For that purpose, the control apparatus includes a ROM, a SRAM, a means for writing data in the SRAM, a selection means for selecting the output from the ROM or the SRAM in accordance with the addresses supplied to the ROM and the SRAM, and a control means for outputting the addresses to the ROM and the SRAM and operating with the output from the selection means as program data.

Abstract: In a control apparatus for operating with program data, it is possible to alter the operation of a control circuit by rewriting the data of the program memory built in an LSI, with ease and at a low cost independently of the operation of the control circuit.

Abstract: An object of the invention is to make it possible to perform, stably in a short time, a focus jump for enabling a focus control on each of a plurality of recording layers of a disc in such a manner that its effect is not absorbed by disturbance or a variation in the movement speed of an objective lens. To attain this object, there are provided means for monitoring the level of a focus error signal, means for rejecting noise from the focus error signal, speed detecting means for detecting a movement speed of an objective lens, and speed control voltage generating means for generating a voltage for controlling the objective lens based on the movement speed detected by the speed detecting means.

Abstract: A video recording/reproducing apparatus capable of discriminating commercial message portions even when a broadcasting mode is the same. A magnetic head records television broadcasting signals to a magnetic tape and reproduces the television broadcasting signals from this magnetic tape. When the television broadcasting signals are reduced by recording/reproducing apparatus, an audio-free portion detector detects audio-free portions from audio signals in the television broadcasting signals. Commercial message (CM) portion detector detects the commercial message portions in the television broadcasting signals by the time intervals among a plurality of audio-free portions detected by the audio-free portion detector, and a CM information memory circuit stores the information of the recording positions of the commercial message portions detected by this commercial message portion detector to the magnetic tape.

Abstract: A video recording/reproducing apparatus capable of discriminating commercial message portions even when a broadcasting mode is the same. A magnetic head records television broadcasting signals to a magnetic tape and reproduces the television broadcasting signals from this magnetic tape. When the television broadcasting signals are reduced by recording/reproducing apparatus, an audio-free portion detector detects audio-free portions from audio signals in the television broadcasting signals. Commercial message (CM) portion detector detects the commercial message portions in the television broadcasting signals by the time intervals among a plurality of audio-free portions detected by the audio-free portion detector, and a CM information memory circuit stores the information of the recording positions of the commercial message portions detected by this commercial message portion detector to the magnetic tape.

Abstract: On the occasion of stopping the tape running at a high speed, a winding radius of the tape supply reel is detected to set the tape deceleration rate (a) on the basis of the detected winding radius of the supply reel. After the tape running speed is decelerated up to the allowable speed VL in the predetermined deceleration rate (a), the tape is stopped by effectuating the brake. Thereby, the tape can be driven at the speed higher than the allowable speed VL without generating any damage, enabling reduction of time required for the fast-forward/rewind operation. Moreover, application flexibility is improved by providing a couple of tape running modes at the first high speed V1 which is higher than the allowable speed VL and the second high speed V2 which is lower than the allowable speed VL.

Abstract: On the occasion of stopping the tape running at a high speed, a winding radius of the tape supply reel is detected to set the tape deceleration rate (a) on the basis of the detected winding radius of the supply reel. After the tape running speed is decelerated up to the allowable speed VL in the predetermined deceleration rate (a), the tape is stopped by effectuating the brake. Thereby, the tape can be driven at the speed higher than the allowable speed VL without generating any damage, enabling reduction of time required for the fast-forward/rewind operation. This can improve application flexibility by providing a couple of tape running modes at the first high speed V1 which is higher than the allowable speed VL and the second high speed V2 which is lower than the allowable speed VL.

Abstract: A video recording/reproducing apparatus capable of discriminating commercial message portions even when a broadcasting mode is the same. A magnetic head records television broadcasting signals to a magnetic tape and reproduces the television broadcasting signals from this magnetic tape. When the television broadcasting signals are reduced by recording/reproducing apparatus, an audio-free portion detector detects audio-free portions from audio signals in the television broadcasting signals. Commercial message (CM) portion detector detects the commercial message portions in the television broadcasting signals by the time intervals among a plurality of audio-free portions detected by the audio-free portion detector, and a CM information memory circuit stores the information of the recording positions of the commercial message portions detected by this commercial message portion detector to the magnetic tape.

Abstract: On the occasion of stopping the tape being run at a high speed, a winding radius of the tape supply reel is detected, and a tape deceleration rate is set in response to the detected winding radius. After the tape running speed is decelerated in the deceleration rate up to a preset speed, VL, at which the tape being run can be stopped without damage, the tape is stopped by a brake means. Thereby, the tape can be driven at a higher speed than the speed, VL, without damage, enabling a reduction of time required for a fast forward/rewind operation.

Abstract: A motor speed control device includes a frequency signal generating circuit for generating a frequency signal proportional to a rotation frequency of a motor, a frequency measuring circuit for measuring a frequency of the frequency signal, a speed error signal extracting circuit for extracting a speed error signal by operation comparing the frequency of the frequency signal with a predetermined control target period, a filter circuit for eliminating rotation frequency components of the motor contained in the frequency signal or the speed error signal and harmonic components thereof to output another speed error signal, and a speed error signal feedback circuit for feeding-back negatively the other speed error signal from the filter circuit to the motor, in which owing to the fact that the filter circuit has predetermined transfer functions, it suppresses non-uniform components contained in the speed error signal and the phase error signal due to the frequency signal (DFG signal) proportional to the rotation s

Abstract: In a digital signal processor for an imaging system, a first pixel signal including first and second color information items and a second pixel signal including third and fourth color information items are alternately outputted to generate an image signal, which is subdivided into a portion to be delayed by a horizontal scanning period and a portion not to be delayed such that these signals are thereafter combined to form an image signal having respective pixel signals so as to achieve a matrix processing on the resultant signal to attain red, blue, and green signals.