Abstract: A disk apparatus (10) includes a spindle (62) to which a magnetooptical disk (60) is attached. An FCM is formed on the magnetooptical disk (60) along a track at intervals of a predetermined period, a laser beam having a different light amount depending on a time of an execution and an interruption of a recording process is incident upon the track. The FCM signal detection circuit (36) detects an FCM signal based on the laser beam reflected from the track, a comparator (42) compares a level of the FCM signal and a slice level, and a PLL circuit (54) generates a clock signal based on a comparison result by the comparator (42). When a change request between an execution/interruption of the recording process is applied, a predetermined first slice level is set to the comparator (42) until 200 mili seconds passes since a reception of the change request. When 200 mili seconds passes, a second slice level calculated based on a peak level of the FCM signal is set to the comparator (42).

Abstract: A disc apparatus (10) includes an optical lens (14). A laser beam is irradiated onto a recording surface of the magneto-optical disc (68) through the optical lens (14), and a TE signal or an RF signal is detected on the basis of the laser beam reflected by the recording surface. Herein, an MPU (50) replaces the optical lens (14) in an optical axis direction, and a TE signal detection circuit (42) or an RF signal detection circuit (60) detects the TE signal or the RF signal at each of lens positions. A laser power is adjusted by the MPU (50) such that amplitude of each of the TE signal or the RF signal detected is below a saturation value. When a parameter is adjusted, a position of the optical lens (14) is controlled such that the amplitude of the TE signal or the RF signal detected thereafter is maximized.

Abstract: In a case of recording data into an optical disk (100), a disk apparatus (10) rotates the optical disk (100) by a ZCLV system, and in a case of reading out the data from the optical disk, the disk apparatus rotates the optical disk by a ZCAV system. By rotating the optical disk by the ZCLV system, a DSP (28) performs a read of a modified read carried out before recording, and a read of a verification carried out after the recording, and thereby, no occurrence of a change of a rotating speed of the optical disk among the modified read, the recording, and the verification.

Abstract: A disk apparatus (10) includes an optical pick-up (12) and a DSP (28), and irradiates a laser beam onto a recording surface of a disk recording medium (100) by the optical pick-up. In a case that a time period (access time period) required for a seek is shorter than a time period (changing time period) required for the number of rotations, the DSP does not simultaneously perform a change of the number of rotations and the seek. To the contrary, the DSP delays the seek by |access time period?changing time period|, and performs a recording and a reproduction after the change of the number of rotation is ended.

Abstract: A disk reproducing apparatus includes a variable gain amplifier (VCA) (32), and the VCA applies a radial push-pull signal including an address signal and an FCM leakage-in signal to a switch (38). The switch outputs only the address signal to a peak-hold circuit (40) on the basis of an FCM mask signal from a mask signal generation circuit (36). The peak-hold circuit generates a peak-hold signal of the address signal so as to be output to a DSP (30), and the DSP controls a gain of the VCA on the basis of the peak-hold signal. Then, the radial push-pull signal in which the gain is controlled on the basis of the address signal is applied to an address detection circuit (42), and the address signal is detected therein.

Abstract: A disk apparatus (10) includes an optical pick-up (12) and a DSP (28), and irradiates a laser beam onto a recording surface of a disk recording medium (100) by the optical pick-up. In a case that a time period (access time period) required for a seek is shorter than a time period (changing time period) required for the number of rotations, the DSP does not simultaneously perform a change of the number of rotations and the seek. To the contrary, the DSP delays the seek by |access time period?changing time period|, and performs a recording and a reproduction after the change of the number of rotation is ended.

Abstract: A disk apparatus includes a DSP (Digital Signal Processor), and the DSP performs a test writing and a test reading on a magneto-optical disk rotated in a ZCLV system to obtain an optimal reproduction laser power value (reference reproduction laser power value) “Pt” at a linear velocity of 30 Mbps in the ZCLV system. Next, by use of a relational expression between a power coefficient and a linear velocity, a linear velocity coefficient “?x” as an optimal reproduction laser power value at a desired linear velocity (zone) “Vx” in a ZCAV system is obtained when the reference reproduction laser power value is multiplied. Then, the optimal reproduction laser power value at the zone in the ZCAV system is obtained by multiplying the reference reproduction laser power value “Pt” by the linear velocity coefficient “?x”.

Abstract: A disc apparatus (10) includes an optical lens (14). A laser beam is irradiated onto a recording surface of the magneto-optical disc (68) through the optical lens (14), and a TE signal or an RF signal is detected on the basis of the laser beam reflected by the recording surface. Herein, an MPU (50) replaces the optical lens (14) in an optical axis direction, and a TE signal detection circuit (42) or an RF signal detection circuit (60) detects the TE signal or the RF signal at each of lens positions. A laser power is adjusted by the MPU (50) such that amplitude of each of the TE signal or the RF signal detected is below a saturation value. When a parameter is adjusted, a position of the optical lens (14) is controlled such that the amplitude of the TE signal or the RF signal detected thereafter is maximized.

Abstract: In a case of recording data into an optical disk (100), a disk apparatus (10) rotates the optical disk (100) by a ZCLV system, and in a case of reading out the data from the optical disk, the disk apparatus rotates the optical disk by a ZCAV system. By rotating the optical disk by the ZCLV system, a DSP (28) performs a read of a modified read carried out before recording, and a read of a verification carried out after the recording, and thereby, no occurrence of a change of a rotating speed of the optical disk among the modified read, the recording, and the verification.

Abstract: A disk apparatus (10) includes a spindle (62) to which a magnetooptical disk (60) is attached. An FCM is formed on the magnetooptical disk (60) along a track at intervals of a predetermined period, a laser beam having a different light amount depending on a time of an execution and an interruption of a recording process is incident upon the track. The FCM signal detection circuit (36) detects an FCM signal based on the laser beam reflected from the track, a comparator (42) compares a level of the FCM signal and a slice level, and a PLL circuit (54) generates a clock signal based on a comparison result by the comparator (42). When a change request between an execution/interruption of the recording process is applied, a predetermined first slice level is set to the comparator (42) until 200 mili seconds passes since a reception of the change request. When 200 mili seconds passes, a second slice level calculated based on a peak level of the FCM signal is set to the comparator (42).

Abstract: A disk reproducing apparatus includes a variable gain amplifier (VCA) (32), and the VCA applies a radial push-pull signal including an address signal and an FCM leakage-in signal to a switch (38). The switch outputs only the address signal to a peak-hold circuit (40) on the basis of an FCM mask signal from a mask signal generation circuit (36). The peak-hold circuit generates a peak-hold signal of the address signal so as to be output to a DSP (30), and the DSP controls a gain of the VCA on the basis of the peak-hold signal. Then, the radial push-pull signal in which the gain is controlled on the basis of the address signal is applied to an address detection circuit (42), and the address signal is detected therein.

Abstract: A magnetic head drive circuit comprises a control circuit for receiving a recording signal for recording data on a recording medium with use of magnetism and producing a control signal based on the recording signal, and a switch circuit comprising switching FETs for changing the direction of current to be passed through a field coil of a magnetic head based on the control signal received from the control circuit. Pch FETs and Nch FETs are both used as the switching FETs. The maximum value of the gate voltage of the switching FETs is lower than the voltage Vd of a coil power source for supplying the current to be passed through the field coil and higher than the gate threshold voltage of the switching FETs.

Abstract: Apparatus for providing MPEG data through which any MPEG decoder, without containing special functionality, can decode and display a slow motion picture. Specifically, to do so, the apparatus when, operating in a normal play mode, provides picture data included in original MPEG data, but when operating in a slow motion mode, provides not only the picture data, included in the original MPEG data, but also dummy data for repeatedly displaying the picture data several times in accordance with a slow motion speed.

Abstract: In tracing a tape with a signal recording head to form tracks having digital data recorded thereon, a plurality of tracks provide each of blocks, and a usual playback data area NA and trick playback areas TH and TL are arranged on each of the tracks included in each block. The trick playback areas are enlarged to provide increment areas TA with a decrease in the bit rate of usual playback data. In recording image data as to a plurality of programs on a tape conjointly, signal recording tracks are formed on the tape, and a usual playback data area and a trick playback data area are formed on each of the tracks or on one track per plurality of tracks, as arranged longitudinally of the track, whereby the image data as to programs A to D is conjointly recorded on the same tape.

Abstract: The present invention relates to a method of converting two-dimensional images into three-dimensional images. In the present invention, a right eye image signal and a left eye image signal between which there is relatively a time difference or a luminance difference are produced from a two-dimensional image signal, thereby to convert two-dimensional images into three-dimensional images. According to the present invention, therefore, it is possible to convert the existing two-dimensional image software into pseudo three-dimensional image software to obtain three-dimensional images.

Abstract: A two-side video disc is manufactured by laminating a top side face disc having a HDTV video signal with red color signal component recorded and a back side face disc having a HDTV video signal with blue color signal component recorded at a position corresponding to the recorded signal on the top side face. Visual end marks are formed at the respective ends of recording tracks of the top side face and back side face discs. The two discs are laminated so that the positions of the end marks coincide with each other. This minimizes deviation in timings between the reproduced signals from the two sides of the disc to reduce significantly the memory capacity of a delay circuit.

Abstract: An erasing beam B1 and a recording beam B2 emitted from a laser diode array 20 are focused on different tracks of a optical magnetic disk D, the erasing beam B1 being focused on a track located ahead of a track on which the recording beam B2 is focused. The reflected beams of the erasing beam B1 and the recording beam B2 are separated respectively into two polarized components by means of a polarized beam splitter 17 and the polarized components are received by photo sensor means 23 and 24. Based on outputs of the photo sensor means 23 and 24, an address signal, a focus error signal and a tracking error signal are obtained. At the time of reproduction, the laser diode array 20 emits a reproducing beam so that the photo sensor means provide a reproducing signal.