Abstract: Magnetic recording and reproducing apparatus including a rotary head drum and power system. The rotary head drum includes at least a rotary head and preamplifier mounted therein. A rotary transformer communicates information signals to/from the rotary head drum and also transmits high-frequency powers signals for operating the pre-amplifer. The transmission occurs at time periods during which recording and reproducing action cannot be performed.
Abstract: A magnetic recording apparatus capable of efficiently erasing data in accordance with a type of magnetic recording medium, comprises a current source, an erase head for erasing data recorded on a recording medium using a supplied erase current, and a current supplying section for supplying an erase current from the current source to the erase head in accordance with input erase current control data. The current supplying section comprises a selecting section for selecting a combination of a plurality of control elements in accordance with the input erase current control data, and a supplying section for supplying an erase current determined in accordance with the selected combination from the current source to the erase head.
Abstract: An improved high speed process for thermomagnetic duplications of color video tapes employing, as the copy tape, tape having a chromium dioxide loading of approximately 10 to 60 mg/dm.sup.2. Also a prerecorded tape made by the improved process.
Abstract: A magnetic recording and reproducing apparatus which can write magnetic information in different recording periods so that information stored in a magnetic medium can be modified or corrected therewith in whichever recording period it is recorded. The apparatus comprises a bias change-over circuit for changing over the voltage to be applied to a magnetic head to effect recording in a recording period which is different from recording and reproducing characteristics of the magnetic head, and a writing circuit for supplying a writing current to the magnetic head in response to a voltage from the bias change-over circuit. Thus, by changing over the writing current, a recording period for recording on the magnetic medium can be modified.
Abstract: A pulse code modulation (PCM) recording and reproducing apparatus for recording analog signals from N channels which are sampled at a predetermined sampling frequency and converted into samples of a variable number of bits each. The samples of PCM data are assembled into a frame consisting of a specific number of samples and the frames are assembled into a number of blocks of PCM data comprising a specific number of tracks. The number of bits per frame is set to a value equal to the least common multiple of all values of bit quantization numbers which the samples may have such that digital signal sources of varying bit quantization formats may be accomodated by the recording apparatus utilizing a simplified structure.
Abstract: A copying apparatus (1) for copying a magnetic pattern from a master magnetic tape (5) on a duplicate magnetic tape (6) comprises two facing elongate platens (9, 10) having mutually parallel gap sides (9A, 10A) which bound a gap (13). Copying means (20) are provided to promote the signal transfer from the master to the duplicate magnetic tape. In the gap sides (9A, 10A) of the platens (9, 10) passages (18) are arranged, through which passages a pressurized fluid is fed into the gap (13), so that the tapes are intimately pressed against one another inside the gap (13). In the gap sides (9A, 10A) expulsion means (16A, 10E, 10K, 23) are provided to expel air present between the tapes, the expulsion means in each gap side, in a view at the gap side, being arranged in at least one V-shape having an axis of symmetry which extends substantially parallel to the longitudinal direction of the platens (9, 10), at least a number of the passages being situated within the outline of the V-shape.
Abstract: Because of increase in data recording density on a magnetic disk in recent years, a minute defect which posed no problem in the past exerts adverse influence upon the recording and reproducing characteristics. An object of the present invention is to provide a method and an apparatus for detecting minute defects on a magnetic disk. In order to achieve this object, the present invention was made on the basis of the recognition that a large defect on the magnetic disk largely decreases the amplitude of the reproduced signal and shifts its phase, whereas a small defect does not decrease the amplitude of the reproduced signal so largely but causes a phase shift. Therefore, defects on the magnetic disk are detected by monitoring the amplitude decrease and phase shift of the reproduced signal.
Abstract: A rotary head type recording apparatus according to the present invention can record information signals on a tape-shaped magnetic recording medium based on a plurality of kinds of recording modes in which track pitches are different from each other, and the track pitches of the recording tracks formed on the taped-shaped magnetic recording medium are varied depending on the kinds of the recording modes and at the same time a pattern of a signal-for-erasion supplied to a rotary type erasing head with wider width in the direction perpendicularly crossing a tracing direction of the head than that of a rotary type magnetic head is varied depending on the kinds of the recording modes, so that the undesirable influence of the signal-for-erasion over the recording of the information signals is reduced and at the same time power consumption is also reduced.
Abstract: A pulse signal conditioner filters and equalizes signal pulses representing digital data whether or not obtained from a magnetic recording device. Modified low pass filters filter the pulse signals and also derive and feed forward the second time derivative of the filtered pulse signals. The filtered pulse and the second time derivative thereof are combined to slim the pulse. Further slimming is provided by delay line equalizers having three paths. A first path for attenuating the pulse signals, a second path for delaying the pulse signals for a first delay, and a third path for delaying the pulse signals for a second delay and attenuation. Pulse signals from the three paths are combined to further slim the pulse.
December 31, 1985
Date of Patent:
October 17, 1989
International Business Machines Corporation
Martin H. Dost, Emil Hopner, Constantin M. Melas, Lionel D. Provazek
Abstract: A data modulation/demodulation system reproducing data that is divided and recorded in a plurality of blocks on a recording medium. The data modulation/demodulation system utilizes the steps of modulating the data by adding specified data bit patterns to the data bits of each block and reproducing the data which have been obtained by adding specified code bit patterns. The bit rows are independently demodulated by demodulation clocks which differ in phase. The demodulation bit pattern of the above code bit pattern which was added at the time of recording and the bit pattern which was demodulated by the different modulation clocks are compared with each other to determine which data is wrong. The correct demodulated data is selected according to this comparison and transmitted.
Abstract: In a magnetic tape recording system having a single master tape player and a plurality of slave recording devices each including at least one rotary magnetic head for repeatedly scanning a respective magnetic recording tape, and each receiving, from the single master tape player, a signal to be recorded along with an external sync or reference signal; each of the slave recording devices is provided with a respective time base adjusting memory in which the signal to be recorded is written in synchronism .with the external reference signal, and from which the signal to be recorded is read-out in synchronism with a reference pulse generated in timed relation to a predetermined rotational position of the respective rotary magnetic head.
Abstract: A multichannel communications recorder with capability to display channel activity, failsafe back-up, and a unique identification code; and apparatus for securing access to the recorder. The recorder is formed from modular elements configurable into a large number of selectable configurations. One or more record decks are controlled by a control module which includes a system control microprocessor and a CRT control microprocessor. Control is provided by selecting functions defined in accordance with a displayed page or moving to another page using softkeys. Access to various pages is controlled by various passwords. Because of the need to provide physical security for recorded tapes, each tape deck is secured by an electro-mechanical lock, which operates under system control. The system is provided with the capability to be configured in configuration providing back-up for selected channels.
Abstract: A method of formatting a storage medium into sectors format the sectors such that each contains an ID field for storing ID information. The ID information includes addresses of a plurality of sectors, preferably the address of the sector containing the ID field and the address of at least one subsequent sector. A drive unit for use with the storage medium formatted as described above reads the ID information from the ID field, and then temporarily stores either the ID information of a sector other than the sector containing the ID field or the result of an evaluation of the ID information, and refers to the stored ID information when the address of the sector corresponding to the stored information is later examined.
June 26, 1986
Date of Patent:
August 29, 1989
Matsushita Electric Industrial Co., Ltd.
Abstract: A recordable data device includes a case and a magnetic disk rotatably contained therein. There, in the case, an insertion opening through which a magnetic head of a disk drive device, constructing a part of a data processing system, can contact the magnetic disk, onto which a recessed identifying embossment has been formed. The magnetic disk drive device comprises an insertion opening or inserting the data recording device and an identifying symbol of a projected embossment which is formed near the insertion opening. When the recordable data device is loaded into the disk drive device, the recessed embossment of the identifying symbol of the magnetic disk is fitted into the projected embossment of the identifying symbol of the magnetic disk drive device. If the data recording device is authentic, the data processing system allows the disk drive device to data to or read data from the magnetic disk.
Abstract: An indicator for representing a selectable recording state of a magnetic disk cassette, for example, a write-protection state, wherein a sliding piece fitted over a thin flat part contiguous with an opening in a lower cassette half is selectively visible through a window through an upper cassette half.
Abstract: An apparatus for recording and reproducing a digital data signal carrying digital information at each periodically appearing reference "P1" phase includes a detector for detecting and producing a phase data signal at each sampling point. Two subsequently sampled phase data are stored in latches for use of the digital data signal by three signal comparators. The first comparator compares the first sampled phase data signal and the second sampled phase data signal. The second comparator compares the first sampled phase data signal with a predetermined value, and the third comparator compares the second sampled phase data signal with the same predetermined value. Utilizing the outputs of the three comparators, a phase condition detector detects whether or not a reference phase is contained between two subsequent sampling points. A detection pulse generator is provided which generates a data detection pulse when the phase condition detector detects the reference phase.
June 18, 1986
Date of Patent:
July 4, 1989
Sharp Kabushiki Kaisha
Hiroshi Ii, Katsubumi Koyanagi, Syuhei Yasuda
Abstract: An automatic cassette tape recorder stop apparatus which can drive a plurality of magnetic tapes simultaneously or individually and includes a sensor for each of the tapes; and a lock release block which receives the load applied to each sensor, rotates a trigger lever through a conversion lever, and actuates a cam gear, a lock release plate and a lock plate. The automatic stop apparatus further includes a load-receiving resilient member for each sensor which does not allow the load on the sensor to be transmitted to the trigger lever while the tape is running but allows the load to be transmitted to the trigger lever for its rotation when the tape has been wound to the end.
Abstract: A vehicle safety and personal message system primarily designed to be incorporated into a vehicle to provide the driver with a pre-recorded speech message pertaining to either a vehicle safety alert or a personal message. The safety alerts include such events as: door ajar, burgler alarm ON or OFF, speed limit exceeded and a fire/police siren detector. The personalized messages includes reminders such as birth dates, anniversaries, meeting date/time and scheduled maintenance periods. All the messages can be recorded in any language and in any local or ethnic jargon and the personal messages may be programmed to occur at anytime within a one-year period. Although the system's primary usage is for vehicles, it can also be adapted for use on many other products that utilize short messages. These products include robotics, ATM machines, telephone answering machines, fire detection devices, toys and numerous other consumer oriented products.
Abstract: A data smoother for a streaming cartridge tape drive includes a circuit for generating a clock signal and a circuit for comparing the phase of the clock signal with the phase of the data signal input to the data smoother. The frequency of the clock signal is increased when the data signal leads the clock signal by an amount which is directly proportional to the phase difference between the clock signal and the data signal, and the frequency of the clock signal is decreased when the data signal lags the clock signal by an amount which is directly proportional to the phase difference between the clock signal and the data signal.
Abstract: When recording domains are formed locally on a recording medium and information is recorded and reproduced by using rise and fall in a reproduced waveform obtained from the recording domains as data, timing patterns indicating start of demodulation are recorded for the lead-edge and the tail-edge of the recording domains, respectively; time interval between the timing signal for starting demodulation detected from the rise in the reproduced waveform and the timing signal for starting demodulation detected from the fall in the reproduced waveform is detected; time shifts of the signals detected from the lead-edge and the tail-edge of the recording domains succeeding the timing patterns for starting demodulation by using the time interval thus detected; and the information is stably detected as time sequential data having no jitter.